1
Introduction
Over the last 30 years, the blood lipid level in the Chinese population has gradually
increased, and the incidence of dyslipidemia has significantly increased. A nationwide
survey in 2012 showed that the average serum total cholesterol (TC) value in adults
was 4.50 mmol/L and that the prevalence of hypercholesterolemia was 4.9%; the average
value of triglyceride (TG) was 1.38 mmol/L, and the prevalence of hypertriglyceridemia
was 13.1%; the average value of high-density lipoprotein cholesterol (HDL-C) was 1.19
mmol/L, and the prevalence of HDL-C hypolipidemia was 33.9%.[1] The overall prevalence
of dyslipidemia among Chinese adults reached 40.4%, which has substantially increased
since 2002. The increase of serum cholesterol level in the population will increase
by approximately 9.2 million cases of cardiovascular events in China between 2010
and 2030.[2] The prevalence of hypercholesterolemia among Chinese children and adolescents
is also significantly increasing,[3] suggesting that the development of dyslipidemia
and the relevant disease burdens in Chinese adults will continue to increase.
Dyslipidemia characterized by the increase of low-density lipoprotein cholesterol
(LDL-C) or TC is an important risk factor for atherosclerotic cardiovascular diseases.
The reduction of LDL-C levels can significantly decrease the development and mortality
risks of atherosclerotic cardiovascular diseases.[4] Other types of dyslipidemia (e.g.,
increases of TG or decreases of HDL-C) are also correlated with the increase of developing
atherosclerotic cardiovascular diseases.[5]–[7]
The effective control of dyslipidemia has important significance for the management
of atherosclerotic cardiovascular diseases in China. Encouraging people to adopt a
healthy lifestyle is the basic strategy for managing dyslipidemia and atherosclerotic
cardiovascular diseases. The focus of dyslipidemia management is to increase the awareness,
treatment, and control rates of dyslipidemia. Although the awareness and treatment
rates of Chinese adult dyslipidemia patients have increased over recent years,[8]
they remain at low levels. Therefore, the management work of dyslipidemia urgently
needs to be strengthened.
In 2007, a joint committee of multidisciplinary experts together formulated the “Chinese
Guidelines for the Management of Dyslipidemia in Adults” (referred to as "Guidelines"
hereafter). Based on the full adoption of epidemiological and clinical study results
from the Chinese population and combined with international study results and guideline
recommendations, the “Guidelines” proposed recommendations that were more appropriate
for the management of dyslipidemia in the Chinese population. These recommendations
had important guiding functions for the management of dyslipidemia in China.[9]
Since 2007, more clinical study results have further validated the effectiveness and
safety of cholesterol-lowering treatments on the primary and secondary prevention
of atherosclerotic cardiovascular diseases. Many international academic institutions
successively updated or formulated new management guidelines for dyslipidemia. During
this period, studies in the clinical blood lipid field in China made significant progress.
Prospective cohort studies on the Chinese population obtained new 20-year follow-up
data. Based on the 10-year overall risk assessment program recommended by the 2007
Guidelines, the lifetime risk assessment program was proposed.[10]
In November 2013, supported by the Department of Diseases Control of the National
Health and Family Planning Commission of the People's Republic of China (NHFPC), the
National Expert Committee on Cardiovascular Diseases of the National Center for Cardiovascular
Diseases, the Chinese Society of Cardiology of Chinese Medical Association, the Chinese
Diabetes Society of the Chinese Medical Association, the Chinese Society of Endocrinology
of the Chinese Medical Association, and the Chinese Society of Laboratory Medicine
of the Chinese Medical Association formed a joint committee to revise the blood lipid
guidelines. These committee members extensively collected core issues to be addressed
by the new guidelines. After discussion, 17 core issues across 4 aspects (the overall
principle of guideline revisions, the overall cardiovascular risk assessment, the
goals of lipid-lowering treatment, and lipid-lowering treatments for special populations)
were eventually confirmed. The guideline-revision working group targeted these core
issues to formulate specific literature retrieval and evaluation strategies as well
as comprehensively evaluate and screen the relevant literature. The literature retrieval
databases included the Chinese Biomedicine Literature Database (CBM), Wanfang Data
Knowledge Service Platform, China National Knowledge Infrastructure (CKNI), the American
Biomedical Literature Database (PubMed), and the Dutch Excerpta Medica database (EMBASE).
In addition, new data from long-term cohort studies in China were used to conduct
targeted analyses. The recommendations and suggestions proposed by the revised guidelines
were developed after repeated discussion among multidisciplinary experts based on
a systemic assessment. When the expert opinions disagreed, the consensus of the majority
of experts was accepted based on a full consideration of the different opinions.
The guideline revision referenced the standard procedures developed by the World Health
Organization (WHO) and the Chinese Medical Association's clinical guidelines.[11]
During the process of guideline revision, the National Center for Cardiovascular Diseases
raised funds to avoid conflicts of interest with vendors.
The definitions of the recommendation classifications in the “Guidelines” reference
the definitions in the relevant European and American blood lipid guidelines.[12],[13]
The specific descriptions are shown below:
Class I: Manipulations or treatments that have been confirmed/unanimously recognized
as beneficial, useful, and effective are recommended.
Class II: Manipulations or treatments that still have contradictions or different
opinions according to useful/effective evidence.
Class IIa: Relevant evidence/opinions tend to be useful/effective. The application
of these manipulations or treatments is reasonable.
Class IIb: Relevant evidence/opinions cannot be fully confirmed as useful/effective.
Its application can be considered.
Class III: It has been confirmed/consistently recognized as useless/ineffective and
manipulations or treatments might be harmful in some cases. Its application is not
recommended.
The definitions of the level of evidence in the “Guidelines” are described below:
Evidence level A: Evidence based on many randomized clinical trials or meta-analyses.
Evidence level B: Evidence based on single randomized clinical trials or many non-randomized
controlled studies.
Evidence level C: Only expert consensus opinion or based on the results of small-scale
studies, retrospective studies, or registry studies.
2
Blood lipids and lipoproteins
Highlights: Blood lipids are the collective term for cholesterol, TG, and lipoids
(e.g., phospholipids) in the serum. Blood lipids that have a close clinical association
are primarily cholesterol and TG. Cholesterol in the human body primarily exists in
the forms of free cholesterol and cholesteryl ester. TG is formed by the fatty acid
esterification of the three hydroxyl groups in the glycerol molecule. Blood lipids
are insoluble in water, and they can be dissolved in water after binding to special
proteins, lipoproteins (Apo), to form lipoproteins that are transferred to tissues
to be metabolized. Lipoproteins are classified as CM, VLDL, IDL, LDL, HDL, and Lp
(a).
Blood lipids are the collective term for cholesterol, TG, and lipoids (e.g., phospholipids)
in serum. Blood lipids that have close clinical association are primarily cholesterol
and TG. The blood lipids that have a close clinical association are primarily cholesterol
and TG. Cholesterol in the human body primarily exists in the forms of free cholesterol
and cholesteryl ester. TG is formed by the fatty acid esterification of the three
hydroxyl groups in the glycerol molecule. Blood lipids are insoluble in water, but
they can be dissolved in water after binding to special proteins, apolipoproteins
(Apo), to form lipoproteins that are transferred to tissues to be metabolized.
Lipoproteins are classified as chylomicrons (CM), very-low-density lipoprotein (VLDL),
intermediate-density lipoprotein (IDL), LDL-C, and HDL-C. One type of lipoprotein
is known as lipoprotein (a) (Lp[a]). The physical properties, main components, sources,
and functions of lipoproteins are listed in Table 1.[14],[15]
Table 1.
The characteristics and functions of lipoproteins.
Classification
Hydration density, g/mL
Particle diameter, nm
Main component
Major apolipoproteins
Sources
Functions
CM
< 0.950
80–500
TG
B48, A1, A2
Synthesis in small intestine
Transfers TG and cholesterol in food from small intestine to other tissues
VLDL
0.950–1.006
30–80
TG
B100, E, Cs
Synthesis in liver
Transfers endogenous TG to the peripheral tissues to release free fatty acids after
lipase hydrolysis
IDL
1.006–1.019
27–30
TG, cholesterol
B100, E
Formed after lipase hydrolysis of TG in VLDL
Belongs to the LDL-C precursor; some are metabolized in liver
LDL-C
1.019–1.063
20–27
Cholesterol
B100
Formed after lipase hydrolysis of TG in VLDL and IDL
The major carrier of cholesterol, taken-up (mediated by LDL-C receptors) and used
by the peripheral tissues. Directly associated with ASCVD
HDL-C
1.063–1.210
8–10
Phospholipid, cholesterol
A1, A2, Cs
Primarily synthesized by liver and small intestine
Promotes the removal of cholesterol from the peripheral tissues. Transfers cholesterol
to liver or other tissues for re-distribution. HDL-C is negatively correlated with
ASCVD
Lp (a)
1.055–1.085
26
Cholesterol
B100, (a)
Complex formed by lipoprotein (a) and LDL-C through disulfide bonds in liver
Might be associated with ASCVD
ASCVD: atherosclerotic cardiovascular disease; CM: chylomicron; HDL-C: high-density
lipoprotein cholesterol; IDL: intermediate-density lipoprotein; LDL-C: low-density
lipoprotein cholesterol; Lp (a): lipoprotein(a); TG: triglyceride; VLDL: very-low-density
lipoprotein cholesterol.
2.1
CM
CM is the largest lipoprotein particle in the blood. The major component is TG, which
accounts for approximately 90% of CM. The density is low. Blood collected after healthy
individuals fast for 12 h shows that no CM exists in serum. After a meal or under
certain pathological conditions when the blood contains a large amount of CM, the
appearance of the blood shows a white turbidity. When the serum tube is stored at
4°C overnight, CM will float to the upper layer of the serum to aggregate, and the
shape is like butter. This simple method is used to examine the presence of CM.
2.2
VLDL
VLDL is synthesized by the liver. Its TG content accounts for approximately 55% of
its mass. VLDL and CM are collectively termed as “TG-rich lipoproteins”. In serum
without the presence of CM, the TG concentration can reflect the amount of VLDL. Because
the VLDL molecule is smaller than CM, the serum after fasting for 12 h is clear and
transparent. When the TG level in fasting serum is > 3.4 mmol/L (300 mg/dL), the serum
will exhibit emulsion luster until it becomes turbid.
2.3
LDL-C
LDL-C is converted from VLDL and IDL (of which TG forms LDL-C after lipase hydrolysis).
The LDL-C particle contains approximately 50% cholesterol, and it is the lipoprotein
in blood with the highest cholesterol content; therefore, it is called a “cholesterol-rich”
lipoprotein. In simple hypercholesterolemia, the increase of the cholesterol concentration
parallels the serum LDL-C level. Because LDL-C particles are small even when the concentration
of LDL-C is high, the serum will not become turbid. More than 95% of the Apo in LDL-C
is Apo B100. Based on particle size and different density levels, LDL-C can be divided
into different sub-components. LDL-C transfers cholesterol to the peripheral tissues.
Most LDL-C is catabolized by hepatocytes and extrahepatic LDL-C receptors.
2.4
HDL-C
HDL-C is primarily synthesized by the liver and small intestine. HDL-C is the smallest
particle lipoprotein. Lipid and protein portions almost account for half of the mass.
The Apo in HDL-C is primarily Apo A1. HDL-C represents a group of heterogeneous lipoprotein
because the quantity and quality of lipids, Apo, enzymes, and lipid transfer proteins
in HDL-C particles are different. Using different separation methods, HDL-C can be
divided into different sub-components. These HDL-C sub-components have different shapes,
densities, particle sizes, electric charges, and anti-atherosclerotic characteristics.
HDL-C transfers cholesterol from the peripheral tissues (including atherosclerotic
plaques) to the liver for recycling or excretion in the form of cholic acid. This
process is called “reverse cholesterol transport”.
2.5
Lp (a)
Lp (a) represents a group of special lipoprotein discovered using immunization methods.
The lipid components of Lp (a) are similar to those of LDL-C. In addition to one molecule
of Apo B100, however, its Apo fraction also contains one molecule of Apo (a). Little
is known about the exact mechanisms of Lp (a) synthesis and catabolism.
2.6
Non-HDL-C
Non-HDL-C refers to the sum of cholesterol in other lipoproteins except for HDL-C.
The calculation formula is non-HDL-C = TC − HDL-C. As a secondary target of lipid-lowering
treatment during the management of atherosclerotic cardiovascular disease (ASCVD)
and the high-risk population, non-HDL-C is applicable for individuals with LDL-C levels
that are not high or have already reached the treatment goal when the TG level is
2.3–5.6 mmol/L (200–500 mg/dL). International blood lipid guidelines recommend using
non-HDL-C as the marker for the primary and secondary prevention of ASCVD.[16]
3
Blood lipid examination
Highlights: The basic items in clinical blood lipid examination are TC, TG, LDL-C,
and HDL-C. The clinical application values of other blood lipid items (e.g., Apo A1,
Apo B, and Lp [a]) have also received increasing attention.
The basic items in clinical blood lipid detection are TC, TG, LDL-C, and HDL-C. The
clinical application values of other blood lipid items (e.g., Apo A1, Apo B, and Lp
[a]) have also received increasing attention.[17]
3.1
TC
TC refers to the total amount of cholesterol in the various lipids in the blood. The
major factors affecting the TC level include the following:
(1) Age and gender. TC levels usually increase with age; however, it no longer increases
or decreases after 70 years old. The level of TC in young and middle-aged women is
lower than that in men. The TC level in women after menopause is higher than that
in age-matched men.
(2) Eating habits. Long-term high cholesterol and high-saturated fatty acid intake
can increase TC.
(3) Genetic factors. Mutations in lipoprotein metabolism-related enzymes or receptor
genes are the major causes of significant increases in TC.
The risk assessment and prediction values of TC on ASCVD are not as accurate as those
of LDL-C. The calculation of non-HDL-C and VLDL-C should detect TC.
3.2
TG
TG level is affected by the effects of genetic and environmental factors and is associated
with race, age, gender, and living habits (e.g., diet and exercise). Unlike TC, TG
shows large variations within and between individuals. The TG level in the same individual
is influenced by factors such as diet and different time points. Therefore, when the
same individual receives multiple detections, the TG values might have significant
differences. The serum TG levels in the population show an obvious positive skew.
Mild-to-moderate increases in TG usually reflect increases in VLDL and its remnant
particles (VLDL with smaller particles). These remnant lipoproteins might directly
cause atherosclerosis because the particles become smaller. However, most studies
suggest that the increase of TG causes atherosclerosis through the influence of the
structures of LDL-C or HDL-C. Survey data indicate that people with mild-to-moderate
increases in serum TG levels are at increased risk for the development of coronary
heart disease.[18] Severely increased TG is usually accompanied by acute pancreatitis.
3.3
LDL-C
Cholesterol accounts for approximately 50% of LDL-C. Therefore, the LDL-C concentration
basically reflects the total amount of LDL-C in the blood. The factors that affect
TC can also affect the LDL-C level. The increase of LDL-C is a major risk factor for
the initiation and progression of atherosclerosis.[12],[16] LDL-C enters into the
vascular wall through the vascular endothelia. LDL-C retained in the subcutaneous
layer is modified into oxidized-LDL (Ox-LDL). After being phagocytized by macrophages,
Ox-LDL forms a foam cell; the latter continues to increase and fuse to become the
lipid core of atherosclerotic plaques. Although the pathology of atherosclerosis exhibits
chronic inflammatory reaction features, LDL-C might be the basic element for the initiation
and maintenance of this chronic inflammatory reaction. Under general conditions, LDL-C
parallels TC; however, the TC level is also influenced by the HDL-C level. Therefore,
it is better to use LDL-C as the assessment indicator for the risk of ASCVD.
3.4
HDL-C
HDL-C can transport cholesterol in peripheral tissues such as the vascular wall to
the liver for catabolism (i.e., reverse cholesterol transport). HDL-C can reduce cholesterol
deposition in the vascular wall to as an anti-atherosclerosis function. Because the
cholesterol content in HDL-C is stable, its current cholesterol content is primarily
measured to indirectly understand HDL-C levels in the blood.
Genetic factors also significantly influence the level of HDL-C. With the significant
reduction of serum TC, people with severe malnutrition have decreased HDL-C. The HDL-C
levels of obese people are also lower. Smoking can reduce HDL-C. Diseases such as
diabetes, hepatitis, and cirrhosis can be accompanied by low HDL-C; however, exercise
and a small amount of alcohol increase HDL-C. Much epidemiological data indicate that
serum HDL-C levels are negatively correlated with the incidence of ASCVD.[19]
3.5
Apo A1
The Apo A1 levels in the normal population are primarily within the range of 1.2–1.6
g/L. The levels in women are slightly higher than those in men. The protein component
of HDL-C particles (i.e., apolipoprotein) accounts for approximately 50% of its mass.
In proteins, Apo A1 accounts for approximately 65%–75%, whereas little Apo A1 is present
in other lipoproteins. Therefore, serum Apo A1 reflects the HDL-C level. It is positively
correlated with HDL-C levels and has a similar clinical significance.
3.6
Apo B
The Apo B levels in the healthy population are primarily within the range of 0.8–1.1
g/L. Under normal conditions, LDL-C, IDL, VLDL, and Lp (a) particles have one molecule
of Apo B. Because LDL-C particles account for the majority of these molecules, approximately
90% Apo B is distributed in LDL-C. There are two types of Apo B: Apo B48 and Apo B100.
The former is primarily present in CM, whereas the latter is primarily present in
LDL-C. Except for special instances, the Apo B routinely measured in clinics usually
refers to Apo B100.
Serum Apo B primarily reflects the LDL-C level and is positively correlated with the
serum LDL-C level. These two types have a similar clinical significance. In a few
cases, Apo B hyperlipidemia and normal LDL-C concentrations can occur, suggesting
the presence of increased small and dense LDL (sLDL) in the blood. During hypertriglyceridemia
(high VLDL), sLDL (LDL pattern B) increases. However, compared with large and light
LDL (LDL pattern A), sLDL particles have a high Apo B content and less cholesterol;
therefore, this condition when LDL-C is not high but serum Apo B increases is called
“Apo B hyperlipidemia”. This situation reflects the increase of LDL pattern B. Therefore,
the measurement of ApoB and LDL-C together can help clinical diagnoses.
3.7
Lp (a)
Serum Lp (a) concentration is primarily associated with genetics. Gender, age, body
weight, and most cholesterol-lowering drugs do not often affect this concentration.
The Lp (a) level in the healthy population shows an obvious skew. Although the level
in individuals can reach above 1,000 mg/L, the level in 80% healthy individuals is
less than 200 mg/L. Usually, 300 mg/L is used as the cutoff point. People with levels
higher than this cutoff are at a significantly increased risk for coronary heart disease,
suggesting that Lp (a) causes atherosclerosis. However, clinical evidence is lacking.[20]
Furthermore, an increase of Lp (a) can also be observed during various acute phase
responses, nephrotic syndrome, diabetic nephropathy, pregnancy, and the administration
of growth hormone. After all types of stress increase are excluded, Lp (a) is considered
as an independent risk factor for ASCVD.
The expression unit of the values of all blood lipid measurement items is mmol/L according
to the national standard of China. Some other countries use mg/dL. The conversion
coefficients are: TC, HDL-C, LDL-C: 1 mg/dL = 0.0259 mmol/L; and TG: 1 mg/dL = 0.0113
mmol/L.
4
Appropriate levels and abnormal cutoff points
Highlights: The appropriate levels and abnormal cutoff points of blood lipids are
primarily applicable for the target population regarding the primary prevention of
ASCVD.
The major hazard of dyslipidemia is the increase of the risk for developing ASCVD.
The “Guidelines” recommend the appropriate levels and abnormal cutoff points for the
blood lipid components in the Chinese population (Table 2) based on the results of
many long-term observatory studies concerning the risk of developing ASCVD in Chinese
populations with different blood lipid levels, including the independent influence
of different blood lipid levels with regard to the cumulative risk for developing
ASCVD in the study populations in 10 and 20 years. In addition, the recommendations
and the references for the appropriate levels of blood lipid components in the many
blood-lipid-related guidelines worldwide are referenced.[12],[16],[21],[22] Importantly,
these appropriate levels and abnormal cutoff points of blood lipids are primarily
applicable for the target population regarding the primary prevention of ASCVD.
Table 2.
The appropriate levels and abnormal stratified standards of blood lipids for the primary
prevention population of ASCVD in China [mmol/L (mg/dL)].
TC
LDL-C
HDL-C
Non-HDL
TG
Ideal level
< 2.6 (100)
< 3.4 (130)
Appropriate level
< 5.2 (200 )
< 3.4 (130)
< 4.1 (160)
< 1.7 (150)
Marginal increase
≥ 5.2 (200) and < 6.2 (240)
≥ 3.4 (130) and < 4.1 (160)
≥ 4.1 (160) and < 4.9 (190)
≥ 1.7(150) and < 2.3 (200)
Increase
≥ 6.2 (240)
≥ 4.1 (160)
≥ 4.9 (190)
≥ 2.3 (200)
Decrease
< 1.0 (40)
ASCVD: atherosclerotic cardiovascular disease; HDL-C: high-density lipoprotein cholesterol;
LDL-C: low-density lipoprotein cholesterol; TC: total cholesterol; TG: triglyceride.
5
Classification of dyslipidemia
Highlights: The classification of dyslipidemia is complicated. The simplest methods
include etiological classification and clinical classification, and the latter is
the most practical.
Dyslipidemia usually refers to increases in cholesterol, TG, or both levels in serum.
This condition is generally called hyperlipidemia. In fact, dyslipidemia also extensively
refers to various blood lipid abnormalities, including HDL-C hypolipidemia. The classification
is complicated. The simplest classifications include the etiological classification
and clinical classification, and the latter is the most practical.[16],[23],[24]
5.1
Etiological classification of dyslipidemia
5.1.1
Secondary hyperlipidemia
Secondary hyperlipidemia refers to dyslipidemia caused by other diseases. The diseases
that can induce dyslipidemia primarily include obesity, diabetes, nephrotic syndrome,
hypothyroidism, renal failure, liver disease, systemic lupus erythematosus, glycogen
storage disease, myeloma, lipoatrophy, acute porphyria, and polycystic ovary syndrome.
In addition, some drugs such as diuretics, non-cardiac selective β-blockers, and glucocorticoids
can also induce secondary dyslipidemia.
5.1.2
Primary hyperlipidemia
In addition to the association between unhealthy lifestyles (e.g., high energy, high
fat, and high sugar diet; excessive drinking; and others) and dyslipidemia, most cases
of primary hyperlipidemia are caused by mutations on a single gene or multiple genes.
Because hyperlipidemia caused by gene mutations has a family aggregation feature and
an obvious genetic tendency (especially in people with a single gene mutation), this
condition is usually called familial hyperlipidemia in the clinic.
For example, loss-of-function mutations on the gene encoding the LDL-C receptor, mutations
on the gene encoding the Apo B that interacts with the LDL-C receptor, gain-of-function
mutations on the gene encoding proprotein convertases subtilisin/kexin type 9 (PCSK9)
that degrades the LDL-C receptor, and mutations on the gene encoding the LDL-C receptor
modulator that modulates the LDL-C receptor to the surface of the plasma cell membrane
can cause familial hypercholesterolemia (FH). In more than 80% of patients, FH is
caused by a single gene mutation; however, hypercholesterolemia is associated with
multiple gene mutations. Loss-of-function mutations on the LDL-C receptor gene are
the major cause of FH. The incidence of homozygous familial hypercholesterolemia (HoFH)
is approximately 1/300,000–1/160,000, whereas the incidence of heterozygous familial
hypercholesterolemia (HeFH) is approximately 1/500–1/200.
Familial hypertriglyceridemia is caused by a single gene mutation. This condition
is usually caused by a gene mutation to the lipoprotein lipases that are involved
in TG metabolism, on the Apo C2 gene, or on the Apo A5 gene. It presents as severe
hypertriglyceridemia (TG >10 mmol/L), and the incidence rate is 1/1000,000. Mild and
moderate hypertriglyceridemia are usually associated with multiple gene mutations.[25],[26]
5.2
Clinical classification of dyslipidemia
In practice, dyslipidemia can be stratified based on a simple clinical classification
(Table 3).
Table 3.
Clinical classification of dyslipidemia.
Type
TC
TG
HDL-C
Equal to WHO phenotype
Hypercholesterolemia
Increase
IIa
Hypertriglyceridemia
Increase
IV, I
Mixed hyperlipidemia
Increase
Increase
IIb, III, IV, V
HDL-C hypolipidemia
Decrease
LDL-C: low-density lipoprotein cholesterol; TC: total cholesterol; TG: triglyceride;
WHO: world health organization.
6
Dyslipidemia screening
Highlights: Regular blood lipid examinations are an important measure for managing
blood lipid levels and cardiovascular disease.
The early detection of individuals with dyslipidemia and the monitoring of their blood
lipid level changes are important for the effective implementation of management measures
for ASCVD. All MAST institutions in China have the ability to determine blood lipid
levels. The detection and monitoring work for patients with dyslipidemia is primarily
implemented through routine blood lipid examination in the populations who visit medical
institutions. These populations include those who already have ASCVD as well as those
who have not developed ASCVD. Health examinations are also an important route to detect
dyslipidemia. For the early detection of dyslipidemia, adults between 20–40 years
old should receive at least one blood lipid measurement (including TC, LDL-C, HDL-C,
and TG) every 5 years. Men older than 40 years of age and postmenopausal women should
receive blood lipid measurements every year. Patients with ASCVD and high-risk populations
should receive one blood lipid measurement every 3–6 months. Patients who are admitted
into hospitals because of ASCVD should receive blood lipid measurements at admission
or within 24 h of admission.
The key participants for blood lipid examination are (1) people with a history of
ASCVD; (2) populations with multiple ASCVD risk factors (e.g., hypertension, diabetes,
obesity, and smoking); (3) people with a family history of early-onset cardiovascular
diseases (i.e., immediate male family members younger than 55 years old or immediate
female family members younger than 65 years old who develop ischemic cardiovascular
disease) or patients with familial hyperlipidemia; and (4) people with skin or tendon
xanthomas and Achilles tendon thickening.
Many factors influence blood lipid detection results. Implementing blood lipid detection
should work according to the requirements of the clinical recommendations for determining
blood lipids (Supplement 1).
7
Overall cardiovascular risk assessment
Highlights: Using different intensities of intervention measures based on the risk
of developing ASCVD is the core strategy for the management of dyslipidemia. Overall
cardiovascular risk assessment is the basis of dyslipidemia treatment decisions. Overall
cardiovascular risk assessment should be performed according to recommended procedures.
For people younger than 55 years old, a lifetime risk for cardiovascular disease should
be considered.
LDL-C or TC levels are independent predictors of the risk of developing ASCVD in individuals
and populations.[27]–[29] However, the risk levels of developing ASCVD in individuals
are determined not only by the level of cholesterol but also by the number and levels
of comorbid risk factors of ASCVD.[29]–[31] Individuals with the same LDL-C level
might have significantly different overall risks regarding the development of ASCVD
because of the different numbers and levels of other risk factors. More importantly,
the overall ASCVD risk is not simply an addition of the cholesterol level and the
independent functions of other risk factors; rather, it is the result of the complicated
interaction between the cholesterol level and many combined risk factors. Therefore,
the same cholesterol level can cause greater harm because of the presence of other
risk factors. The comprehensive assessment of the overall risk of ASCVD is a necessary
prerequisite for the management of dyslipidemia. The assessment of the overall risk
of ASCVD can not only help to confirm the decision of lipid-lowering treatment for
patients dyslipidemia but also help clinical physicians make personalized comprehensive
treatment decisions targeting multiple risk factors, thereby reducing the overall
risk of ASCVD in patients to the greatest degree. Currently, the core content of the
dyslipidemia management guidelines released by China and other countries include the
assessment methods and risk stratification standards for the overall risk of developing
ASCVD.[9],[12],[13],[16],[22],[32]–[35] The 2007 blood lipid guidelines proposed using
the risk of development of “ischemic cardiovascular disease” (i.e., coronary heart
disease and ischemic stroke) to reflect the comprehensive pathogenic risk of the major
risk factors of dyslipidemia and other cardiovascular diseases. For people at moderate
risk of developing ASCVD in 10 years who are < 55 years old, this edition of the “Guidelines”
add recommendations for the assessment of the lifetime risk of ASCVD for the early
recognition of individuals with a high lifetime risk of ASCVD to perform active interventions.[10]
During risk assessment, people who have been diagnosed with ASCVD are directly listed
as a high-risk population. People who meet one of the following conditions are directly
listed as a high-risk population: (1) LDL-C ≥ 4.9 mmol/L (190 mg/dL); (2) 1.8 mmol/L
(70 mg/dL) ≤ LDL-C <4.9 mmol/L (190 mg/dL), and diabetes patients older than 40 years
of age. The very high-risk and high-risk populations who meet the above conditions
do not need to receive an ASCVD risk stratification based on their number of risk
factors.
When considering whether a lipid-lowering treatment is required, individuals who do
not meet the above three conditions should receive an assessment of the overall risk
of developing ASCVD over the following 10 years according to the procedures shown
in Figure 1. The risk assessment revised in the “Guidelines” has 21 combinations according
to the level of LDL-C or TC, the presence of hypertension, and the number of other
ASCVD risk factors. In addition, according to the average 10-year incidence risk of
ASCVD across different combinations, these levels are defined as low-risk, medium-risk,
and high-risk: < 5%, 5%–9%, and ≥ 10%, respectively. This revision continues the risk-stratification
program published in the 2007 Blood Lipid Guidelines to use hypertension as an important
parameter in risk stratification (Figure 1). This version of the “Guidelines” provides
a more quantitative color figure of the risk stratification of ASCVD development as
the reference for risk stratification (Supplement 2).
Figure 1.
The risk assessment flow chart of ASCVD.
*Including smoking, low HDL-C, and men ≥ 45 years of age or women ≥ 55 years of age.
The risk assessment and treatment of patients with chronic kidney disease refer to
the treatment of dyslipidemia in special populations. ASCVD: atherosclerotic cardiovascular
disease; BMI: body mass index; CM: chylomicron; HDL-C: high-density lipoprotein cholesterol;
IDL: intermediate-density lipoprotein; LDL-C: low-density lipoprotein cholesterol;
TC: total cholesterol; TG: triglyceride; VLDL: very-low-density lipoprotein cholesterol.
Because studies in China and other countries have already discovered the effect of
the risk factor levels on the lifetime risk of people younger than 55 years old,[10],[31],[36],[37]
this revision of the “Guidelines” recommends assessing the lifetime risk of ASCVD
in people who have medium 10-year incidence risk for ASCVD to identify middle-aged
and young individuals who have high lifetime risks for developing ASCVD in 10 years
to perform early interventions on certain risk factors including blood lipids. If
people with medium 10-year incidence risk of ASCVD have any two or more of the following
risk factors, then their lifetime risk of ASCVD is high: (1) systolic pressure ≥ 160
mmHg or diastolic pressure ≥ 100 mmHg; (2) non-HDL-C ≥ 5.2 mmol/L (200 mg/dL); (3)
HDL-C <1.0 mmol/L (40 mg/dL); (4) body mass index (BMI) ≥ 28 kg/m2; and (5) smoking.
8
Principles of dyslipidemia treatment
Highlights: Very high-risk, LDL-C < 1.8 mmol/L; high-risk, LDL-C < 2.6 mmol/L; medium-risk
and low-risk, LDL-C < 3.4 mmol/L.
People who cannot achieve the target value because the baseline value of LDL-C is
higher should reduce LDL-C values by at least 50%. Very-high-risk people who have
LDL-C baseline values within the target still should reduce LDL-C levels by approximately
30%.
For clinical lipid-lowering goal attainment, statin lipid-lowering drugs are preferred.
At the beginning of treatment, medium-intensity statins should be applied. Doses should
be properly adjusted according to individual lipid-lowering efficacy and tolerance
conditions. If the cholesterol level cannot reach the goal, then other lipid-lowering
drugs can be used in combination.
Dyslipidemia treatment seeks to manage ASCVD and reduce the incidence risk of clinical
cardiovascular events, such as myocardial infarction, and ischemic strike, and coronary
heart disease mortality. Because of the differences in genetic background and living
environments, the risk levels of the development of ASCVD among individuals significantly
differ. Lipid-lowering treatment can benefit patients with ASCVD and high-risk populations.
Whether the lipid-lowering drug treatment should be initiated should be based on the
risk levels of ASCVD in individuals in the clinic (Class I recommendation, Level A
evidence).
8.1
Lipid-lowering treatment targets
Dyslipidemia, especially an increase in LDL-C, is the key factor that causes the initiation
and progression of ASCVD. Many clinical studies have repeatedly confirmed that regardless
of the drugs or measures adopted, as long as the serum LDL-C level can be reduced,
atherosclerotic lesions can be stably delayed or regressed, and the incidence, morbidity,
and mortality of ASCVD can be significantly reduced. All of the guidelines for the
management of dyslipidemia in China and other countries emphasize that LDL-C plays
a core role in developing ASCVD, and they advocate reducing serum LDL-C levels to
manage ASCVD risk.[9],[12],[35],[38] Therefore, the use of LDL-C as the preferred
intervention target is recommended (Class I recommendation, Level A evidence).
Non-HDL-C can be used as the secondary intervention target (Class IIa recommendation,
Level B evidence). Given that patients with hypertriglyceridemia have increased remnant
lipoproteins in their bodies that might cause atherosclerosis, non-HDL-C is used as
the secondary intervention target.
8.2
Setting up lipid-lowering target values
Clinical physicians are familiar with establishing target values of lipid-lowering
treatments and have experience applying such measures. However, certain newly published
dyslipidemia diagnoses and treatment guidelines in other countries do not recommend
establishing lipid-lowering target values,[12],[35] because no evidence from randomized
controlled studies support the specific target values of blood lipid treatment, and
it is not known what type of blood lipid target values engender the largest degree
of reduction of the risks of ASCVD. However, if lipid-lowering target values are eliminated,
then the compliance of patients who take lipid-lowering drugs will be severely affected.
Regarding the benefits of lipid-lowering treatment, a long-term adherence to treatment
is important. Only when lipid-lowering target values are established can physicians
more accurately evaluate the effectiveness of treatment methods, effectively communicate
with patients, and increase the compliance of patients regarding lipid-lowering drugs.
Furthermore, no evidence or reasons exists to eliminate lipid-lowering target values
in China.[38],[39] Therefore, target values should be established in a lipid-lowering
treatment (Class I recommendation, Level C evidence).
8.3
Lipid-lowering goal attainment values
The basic target value of cholesterol to be achieved in lipid-lowering treatment should
be confirmed according to the different risk levels of ASCVD. The recommendation for
the reduction of LDL-C to a certain cutoff point (i.e., target value) is primarily
based on risk-benefit analysis; when the risk for developing a cardiovascular event
in the future is high, the benefit is larger. Although LDL-C might be reduced to a
lower level, more clinical cardiovascular benefits exist, and the drug-related adverse
reactions will also significantly increase. In addition, health economics are also
important factors that affect making treatment decisions and should be considered.
Patients who are diagnosed with ASCVD [including acute coronary syndrome (ACS)], stable
coronary heart disease, post revascularization, ischemic cardiomyopathy, ischemic
stroke, transient ischemic attack (TIA), and peripheral atherosclerosis in the clinic
all belong to the very high-risk population.[13],[35] In the non-ASCVD population,
risk assessment is performed according to cholesterol level, its severity, and the
number of risk factors. These patients are divided into high-risk, medium-risk, and
low-risk groups. The target value for reducing LDL-C is determined based on the risk
of developing ASCVD among individuals. The LDL-C and non-HDL-C target values that
must be achieved by populations with different risks show large differences (Table
4, Class I recommendation, Level B evidence).
Table 4.
The goal attainment values of LDL-C and non-HDL-C treatments across different ASCVD
risk populations [mmol/L (mg/dL)].
Risk level
LDL-C
Non-HDL-C
Low/medium risk
< 3.4 (130)
< 4.1 (160)
High risk
< 2.6 (100)
< 3.4 (130)
Very high risk
< 1.8 (70)
< 2.6 (100)
HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol.
All clinical study results of enhanced statin therapy show that several increased
doses of statins can reduce the risk of developing ASCVD events; however, the absolute
values of these benefits are small, and the all-cause mortality is not decreased.[40]
Studies of statins combined with ezetimibe treatment have also obtained similar results.[41]
Reduction of LDL-C from 1.8 mmol/L to 1.4 mmol/L can further reduce the absolute risk
of cardiovascular events by 2% and the relative risk by 6.4%; however, the risks of
cardiovascular mortality and all-cause mortality are not reduced. These results suggest
that although a clinical benefit exists after LDL-C is reduced, the absolute benefits
are already decreased.
If the baseline value of LDL-C is high, then LDL-C is difficult to reduce to the basic
target value after treatment with the existing standard lipid-lowering treatment for
3 months. Thus, the alternative goal of at least 50% reduction of LDL-C should be
considered (Class IIa recommendation, Level B evidence). In the clinic, the LDL-C
baseline values of certain very-high-risk patients are already within the basic target
values. At this time, LDL-C can be reduced by approximately 30% from the baseline
value (Class I recommendation, Level A evidence).
The target value of non-HDL-C is higher than that of LDL-C by 0.8 mmol/L (30 mg/dl).
The target values of non-HDL-C treatment in populations at different risks are shown
in Table 4 (Class I recommendation, Level B evidence).
8.4
Lipid-lowering goal attainment strategy
Over the last 20 years, the results of many large-scale clinical trials consistently
show that statins can significantly reduce the risk of cardiovascular events (including
myocardial infarction, coronary heart disease mortality, ischemic stroke, and others)
with regard to the primary and secondary prevention of ASCVD. Statins have already
become the most important drugs in the management of this group of diseases. Therefore,
to lower lipids, statins should be a first-line treatment chosen in clinical practice
(Class I recommendation, Level A evidence).
However, how to reasonably and effectively use statins remains controversial. Recent
guidelines in other countries recommend using high-intensity (equivalent to the maximum
allowable dose) statins at the beginning of clinical practice. However, the increased
benefits and safety of the maximum allowable dose of statins in the Chinese population
have not been confirmed.[42] The HPS2-THRIVE study indicates that the Chinese population
can achieve lower LDL-C levels than their European counterparts when the exact same
statin drug and dose are used.[43] The DYSIS-CHINA study showed that an increase of
statin doses does not increase the goal attainment rate of LDL-C.[44] The CHILLAS
study did not show that Chinese patients with ACS obtain more benefits from high-intensity
statins.[45] In the Chinese population, safety must be considered during the use of
high-intensity statins. More studies have indicated that high-intensity statin therapy
is accompanied by high risks of myopathy and increases in the liver enzymes that are
more prominent in the Chinese population. The HPS2-THRIVE study indicated that the
incidence of adverse liver reactions was significantly higher in Chinese patients
than in European patients during treatment with medium-intensity statins. The rate
of increase in liver enzymes (> 3 times of the upper limit of the normal value) was
more than 10 times higher than that among European patients, and the risk of myopathy
was also 10 times higher. Currently, no safety data exist regarding high-intensity
statin therapy in the Chinese population.
One feature of the efficacy of lipid-lowering statin drugs is that the initial dose
of every statin has excellent lipid-lowering efficacy. When the dose is doubled, LDL-C
is further reduced by 6% (the statin efficacy “rule of six”). When the statin dose
is doubled, the drug cost proportionally increases, whereas the increase of the efficacy
for LDL-C reduction is relative small. Therefore, the use of medium-intensity statins
is recommended for initial treatment. The dose is properly adjusted according to individual
lipid-lowering efficacy and tolerance conditions. If the cholesterol level does not
reach the target, then other lipid-lowering drugs (e.g., ezetimibe) can be used in
combination to obtain safe and effective lipid-lowering effects (Class I recommendation,
Level B evidence).
8.5
Other dyslipidemia interventions
In addition to active cholesterol interventions, whether other dyslipidemia conditions
also require treatment lacks the evidence of relevant clinical trial benefits. The
appropriate level of serum TG is < 1.7 mmol/L (150 mg/dL). When serum TG is ≥ 1.7
mmol/L (150 mg/dL), non-drug intervention measurement is first applied including therapeutic
diet, reduction of body weight, and abstinence from alcohol. If the TG level only
shows a mild-to-moderate increase [i.e., 2.3–5.6 mmol/L (200–500 mg/dL)] to manage
the risk of ASCVD, then although the reduction of the LDL-C level is the major goal,
non-HDL-C should also reach the target value. If non-HDL-C cannot reach the target
value even after statin therapy, then fibrates and high purity fish oil preparations
should be used additionally with statins. For patients with severe hypertriglyceridemia
and fasting TG levels of ≥ 5.7 mmol/L (500 mg/dL), drugs that reduce TG and VLDL-C
should be considered first (e.g., fibrates, high purity fish oil preparations, or
niacin).
For people with HDL-C < 1.0 mmol/L (40 mg/dL), diet should be controlled and lifestyle
should be improved. Currently, not enough evidence exists for drug interventions.
8.6
Lifestyle interventions
Diet and lifestyle typically and significantly influence dyslipidemia. Dietary treatment
and lifestyle improvements are the basic measures of dyslipidemia treatment. Whether
a drug lipid-lowering therapy is performed, diet control and lifestyle improvement
must be assured (Class I recommendation, Level A evidence). Excellent lifestyle habits
include adhering to a heart-healthy diet and regular exercise, avoiding tobacco, and
maintaining an ideal body weight. Lifestyle intervention is the therapeutic measure
with the best cost-benefit and risk-benefit ratios.
For low- and medium-risk patients, if LDL-C fails to reach the goal after 6 months
of lifestyle intervention, then a low/medium intensity statin therapy is initiated.
For high- and very-high-risk patients, a medium-intensity statin drug treatment is
initiated immediately combined with a lifestyle intervention.
8.7
Treatment process monitoring
Patients with dietary and non-drug treatment should test their blood lipid levels
again in the first 3–6 months. If blood lipid control reaches the recommended target,
then the non-drug treatment should continue and re-examinations should be performed
every 6 months to 1 year. People who have attained long-term goals should receive
a re-examination once every year. People who take lipid-lowering drugs require closer
blood-lipid monitoring. People who take lipid-lowering drugs for the first time should
receive re-examinations for blood lipids, transaminases, and creatine kinase within
6 weeks of drug administration. If their blood lipids reach the target value and no
adverse drug reaction exists, then re-examination should be gradually changed to once
every 6–12 months. If blood lipid levels do not reach the goal and no adverse drug
reaction occurs, then monitoring should be performed once every 3 months. If blood
lipids do not reach the target value even after 3–6 months of treatment, the dose
and type of lipid-lowering drugs should be adjusted, or the treatment should be combined
with lipid-lowering drugs with different action mechanisms. After each adjustment
of the type or dose of lipid-lowering drugs, re-examination should be performed within
6 weeks of treatment. Therapeutic lifestyle change (TLC) and lipid-lowering drug treatment
must be continued over the long term to obtain excellent clinical benefits.
9
Therapeutic lifestyle changes
Highlights: Total energy is controlled by fulfilling the requirement of daily essential
nutrition. The percentage of composition of all nutritional elements should be selected
reasonably. People should control body weight, quit smoking, limit drinking, and adhere
to regular medium-intensity metabolic exercise.
Dyslipidemia is closely associated with diet and lifestyle. Dietary therapy and lifestyle
improvement are the basic measures of dyslipidemia treatment.[46] Whether the lipid-lowering
drug treatment is chosen, control of diet and improvement of lifestyle should be maintained
(Table 5). Daily essential nutrition and total energy requirements should be met when
the total amount of saturated fatty acid and trans-fat uptake exceeds the upper limit;
these compounds should be replaced with unsaturated fatty acids. The recommended daily
cholesterol intake is < 300 mg; lipid intake should not be > 20%–30% total energy,
especially for high-risk people for ASCVD and other similar conditions. Saturated
fatty acid intake should be < 10% total energy for the general population. For patients
with hypercholesterolemia, the amount of saturated fatty acid intake should be < 7%
total energy, and the amount of trans-fat intake should be <1% total energy. Patients
with hypertriglyceridemia should reduce their total amount of daily fat intake as
low as possible, and their daily consumption of cooking oil should be < 30 g. Regarding
lipid intake, food that is rich in omega-3 polyunsaturated fatty acids should be selected
first (e.g., deep-sea fish, fish oil, and vegetable oil).
Table 5.
Basic lifestyle change elements.
Element
Recommendation
Limiting dietary ingredients that can increase LDL-C
Saturated fatty acid
< 7% of total energy
Dietary cholesterol
< 300 mg/dL
Increasing dietary ingredients to reduce LDL-C
Plant sterols
2–3 g/dL
Water soluble dietary fiber
10–25 g/dL
Total energy
Adjusting to the level that can maintain ideal body weight or reduce body weight
Physical activity
Maintaining medium-intensity exercise and consuming at least 200 kcal
LDL-C: low-density lipoprotein cholesterol.
The recommended daily carbohydrate intake accounts for 50%–65% of total energy. Carbohydrates
rich in dietary fibers and low in glycemic index should be chosen to replace saturated
fatty acids. Daily diets should include 25–40 g of dietary fiber (7–13 g of water-soluble
dietary fiber). The carbohydrate intake should be primarily cereals, tubers, and whole
grains. The intake of added sugar should not be over 10% total energy (this percentage
is lower for people with obesity or hypertriglyceridemia). Food additives such as
plant sterols/alkanols (2–3 g/dL) and soluble/viscous dietary fibers (10–25 g/dL)
can help with blood lipid control; however, their safety requires long-term monitoring.
9.1
Controlling body weight
Obesity is an important risk factor for dyslipidemia. Overweight or obese people with
dyslipidemia should uptake less energy than the body energy consumed to gradually
reduce body weight to the ideal status. Reducing the total energy from daily food
(by 300–500 kcal daily), improving dietary structure, and increasing physical activity
can reduce more than 10% body weight in overweight and obese people. The maintenance
of a health body weight (BMI: 20.0–23.9 kg/m2) is conducive to blood lipid control.
9.2
Physical activity
Medium-intensity metabolic exercise is recommended for 5–7 days every week, 30 min
each time. Patients with ASCVD should first perform an exercise load test; after the
safety of this exercise has been fully evaluated, physical activity is then performed.
9.3
Quit smoking
Patients should completely quit smoking and effectively avoid the inhalation of secondhand
smoke to prevent ASCVD and to increase HDL-C levels. Smoking cessation treatments,
smoking cessation hotline consultation, and medicines can be used to help quit smoking.
9.4
Limit drinking
A moderate amount of drinking (20–30 g of alcohol daily for men and 10–20 g of alcohol
daily for women) can increase HDL-C levels. Even a small amount of drinking can further
increase TG levels in patients with hypertriglyceridemia. No exact evidence exists
regarding the influence of drinking on cardiovascular events. Restricted drinking
is advocated.
10
Lipid-lowering drug treatments
Highlights: Whether the lipid-lowering drug treatment should be initiated should be
based on the risk levels of ASCVD in individuals in the clinic.
The reduction of LDL-C levels should be used as the preferred intervention target
in the management of ASCVD risks. Non-HDL-C can be used as the secondary intervention
target.
Lipid-lowering treatment should establish very high-risk, LDL-C < 1.8 mmol/L; high-risk,
LDL-C < 2.6 mmol/L; medium-risk and low-risk, LDL-C < 3.4 mmol/L.
People who cannot achieve the target value because the baseline value of LDL-C is
higher should reduce LDL-C values by at least 50%. Very-high-risk people who have
LDL-C baseline values within the target still should reduce LDL-C levels by approximately
30%.
For clinical lipid-lowering goal attainment, statin lipid-lowering drugs are preferred.
At the beginning of treatment, medium-intensity statins should be applied. Doses should
be properly adjusted according to individual lipid-lowering efficacy and tolerance
conditions. If the cholesterol level cannot reach the goal, then other lipid-lowering
drugs can be used in combination.
The blood lipid metabolic pathway in the human body is complicated. Many enzymes,
receptors, and transport proteins are involved. Many types of lipid-lowering drugs
can be chosen in clinical practice. Generally, these drugs can be divided into two
large groups: (1) drugs that primarily reduce cholesterol; and (2) drugs that primarily
reduce TG. Some lipid-lowering drugs can reduce both cholesterol and TG. Severe hyperlipidemia
usually requires the combined application of many lipid-lowering drugs to obtain excellent
efficacy.
10.1
Drugs that primarily reduce cholesterol
The major action mechanisms of this group of drugs inhibit cholesterol synthesis in
hepatocytes, accelerate LDL-C catabolism, or reduce cholesterol absorption in the
intestinal tract. This group of drugs includes statins, cholesterol absorption inhibitors,
probucol, bile acid sequestrants, and other lipid-lowering drugs (e.g., Zhibitai and
policosanol).
10.1.1
Statins
Statins, also known as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors,
can inhibit the rate-limiting enzyme of cholesterol synthesis (HMG-CoA reductase)
to reduce cholesterol synthesis and further upregulate the LDL-C receptor on the cell
surface and accelerate serum LDL-C catabolism. In addition, statins can also inhibit
VLDL synthesis. Therefore, statins can significantly reduce serum TC, LDL-C, and Apo
B levels as well as reduce serum TG levels and mildly increase HDL-C levels.
The advent of statins was a milestone in the history of human ASCVD management. The
4S clinical trial first confirmed that statins reduce coronary heart disease mortality
and overall patient mortality.[47] The subsequent CARE,[48] LIPID,[49] and LIPS[50]
studies also confirmed the important functions of this group of drugs with regard
to the secondary prevention of coronary heart disease. The HPS study indicated that
statin therapy benefits the high-risk population when their baseline cholesterol is
not high.[51] The clinical trials regarding enhanced statin therapy primarily included
PROVE-IT,[52] A to Z,[53] TNT,[54] MIRACL,[55] and IDEAL.[56] Compared with the routine
dose of statins, enhanced statin therapy for patients with coronary heart disease
further reduces the likelihood of cardiovascular events;[52],[54] however, the reduction
level is not high,[53],[56] and total mortality is not reduced.[57] The ASTEROID study
confirmed that statin therapy reverses coronary atherosclerosis.[58] The WOSCOPS,[59]
AFCAPS/TexCAPS,[60] CARDS,[61] JUPITER,[62] and HPS[51] studies expanded the application
of statins from patients with ASCVD to primary prevention and more extensive populations.
Currently, the function of statins with regard to the primary prevention of cardiovascular
disease among high-risk populations has been affirmed. However, the application effect
in people at low risk of cardiovascular disease awaits further study. Many studies
have targeted special populations for investigation. The SPARCL,[63] PROSPER,[64]
CARDS,[61] ALLHAT-LLT,[65] and ASCOT-LLA[66] studies individually showed that statins
have clinical benefits in the elderly as well as patients with stroke, diabetes, or
hypertension. Furthermore, evidence from Chinese clinical studies does not support
the cardiovascular benefits of short-term enhanced statin therapy before percutaneous
coronary intervention (PCI) among patients with ACS. Moreover, the newest guidelines
in other countries do not recommend short-term enhanced statin intervention strategies
during the perioperative period of PCI.
Statins are applicable for patients with hypercholesterolemia, mixed hyperlipidemia,
or ASCVD. Currently, lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin,
rosuvastatin, and pitavastatin are used in clinical practice in China. The cholesterol
reduction levels have large differences depending on the different types and doses
of statins. However, when any statin does is doubled, the continued reduction of LDL-C
is only 6% (i.e., the so-called “rule of six of statin efficacy”). Statins can reduce
TG levels by 7%–30% and increase HDL-C levels by 5%–15%.
Statins can be administered once per day at any time. However, the administration
of LDL-C at night might be associated with higher levels of LDL-C reduction. After
the expected efficacy of statin administration is obtained, the long-term administration
should be continued. If patients can tolerate this treatment, then drug withdrawal
should be avoided. Previous studies have suggested that statin withdrawal might increase
the development of cardiovascular events.[67] If adverse reactions occur after statin
administration, then this treatment should be replaced with another type of statin,
the dose should be reduced, and drug administration should be performed every other
day;[68] otherwise, other non-statin lipid lowering drugs should be used.
The analytic results of the Cholesterol Treatment Trials' (CTT) collaboration indicate
that when LDL-C is reduced by 1 mmol/L after statin therapy in populations with different
cardiovascular risk stratifications, the relative risk of major cardiovascular events
is reduced by 20%, and all-cause mortality is reduced by 10%, whereas the mortality
caused by non-cardiovascular reasons does not increase.[57],[69] Current studies have
repeatedly confirmed that the level of clinical reduction benefits of ASCVD by statins
is linearly and positively correlated with the level of LDL-C reduction. The clinical
benefits produced by statin therapy originate from the effect of LDL-C reduction.
The levels of LDL-C reduction via different types and doses of statins are shown in
Table 6.[35]
Although Xuezhikang capsules are classified as a lipid-lowering Chinese medicine,
their lipid-lowering mechanism is similar to that of statins. These capsules are refined
via the biological fermentation of a special monascus added to rice using the modern
GMP standard manufacturing process. The main ingredients of these capsules include
13 types of natural statin compounds, including lovastatin without a crystal structure
and its homologs. The commonly used dose is 0.6 g twice per day. The China Coronary
Secondary Prevention Study (CCSPS) and other clinical studies confirmed that Xuezhikang
capsules reduce cholesterol and significantly reduce the overall mortality of patients
with coronary heart disease, the incidence of cardiovascular events, and number of
side effects.[70]–[73]
Table 6.
The cholesterol reduction intensity of stains.
High intensity (daily dose can reduce LDL-C by ≥ 50%)
Medium intensity (daily dose can reduce LDL-C by 25%–50%)
Atorvastatin 40–80 mg*
Atorvastatin 10–20 mg
Rosuvastatin 20 mg
Rosuvastatin 5–10 mg
Fluvastatin 80 mg
Lovastatin 40 mg
Pitavastatin 2–4 mg
Pravastatin 40 mg
Simvastatin 20–40 mg
Xuezhikang 1.2 g
*Studies of atorvastatin (80 mg) among the Chinese population are limited; please
use with caution. LDL-C: low-density lipoprotein cholesterol.
Most people show excellent tolerance to statins. Adverse reactions are primarily observed
in patients who receive large doses of statin therapy. The most common manifestations
are discussed below.
(1) Abnormal liver function.[74],[75] The main presentation of this condition is the
increase of transaminases. The incidence is approximately 0.5%–3%, and it shows dose
dependence. Patients with an increase of serum alanine aminotransferase (A), aspartate
aminotransferase (AST) higher than three times the upper limit of normal values, and
the combined increase of total bilirubin should reduce or discontinue drug use. Patients
with an increase of transaminases within three times of the upper limit of normal
values can be observed based on the original doses or reduced doses. Some patients
can restore normal transaminases after this treatment. The application contraindications
of statins are decompensated cirrhosis and acute liver failure.
(2) Statin-related adverse muscle reactions include myalgia, myositis, and rhabdomyolysis.[76],[77]
When patients have muscle discomfort, weakness, or both and continuous creatine kinase
detection shows progressive increases, statins doses should be reduced or the drugs
should be discontinued.
(3) The long-term administration of statins might increase the risk of new-onset diabetes.[78]
The incidence is approximately 10%–12%, and it is classified as a statin effect. The
overall benefits of statins on cardiovascular diseases are more significant than the
risk of new-onset diabetes. Patients with diabetes or those at high risk for diabetes
who have statin therapy indications should adhere to the administration of this group
of drugs.
(4) Statin therapy can cause cognitive dysfunction.[79] However, this dysfunction
is transient, and its incidence is not high. The results of a meta-analysis showed
that statins do not have adverse effects on renal function.[80] The adverse reactions
of statins also include headache, insomnia, and depression as well as digestive tract
symptoms such as indigestion, diarrhea, abdominal pain, and nausea.
10.1.2
Cholesterol absorption inhibitors
Ezetimibe can effectively inhibit cholesterol absorption in the intestinal tract.
The IMPROVE-IT study indicated that the administration of ezetimibe based on simvastatin
further reduces the likelihood of cardiovascular events in patients with ACS.[41]
The SHARP study showed that a combined treatment with ezetimibe and simvastatin improves
cardiovascular disease prognosis in patients with CKD[81]. The recommended dose of
ezetimibe is 10 mg/d. This drug shows excellent safety and tolerance, and the adverse
reactions are mild and mostly transient. The major presentations are headache and
digestive tract symptoms. When combined with statins, ezetimibe can produce adverse
reactions such as transaminase increases and myalgia. Ezetimibe is prohibited during
pregnancy and lactation.
10.1.3
Probucol
Probucol influences lipoprotein metabolism through an incorporation into the core
of LDL-C particles; thus, LDL-C is easily cleared through the non-receptor pathway.
The commonly used dose of probucol is 0.5 g twice per day. This drug is primarily
applicable for patients with hyperlipidemia, especially those with HoFH or xanthoma.
Probucol relieves skin xanthomas.[82],[83] Its common adverse reactions are gastrointestinal
in nature. Probucol can also induce dizziness, headache, insomnia, and skin rash.
Rare but severe adverse reactions include QT interval prolongation. Probucol is prohibited
for patients with ventricular arrhythmia, QT interval prolongation, or hypokalemia.
10.1.4
Bile acid sequestrants
Bile acid sequestrants are basic anion exchange resins. They can block the reabsorption
of cholesterol in the bile acid in the intestinal tract.[84] The clinical dosage of
cholestyramine is 5 g three times per day, 5 g of colestipol three times per day,
and 1.875 g of colesevelam twice per day. When combined with statins, these drugs
can significantly increase lipid-lowering efficacy. The most common adverse reactions
include gastrointestinal discomfort and constipation; furthermore, they can influence
the absorption of certain drugs. The absolute contraindications of this group of drugs
are abnormal dysbetalipoproteinemia and serum TG > 4.5 mmol/L (400 mg/day).
10.1.5
Other lipid-lowering drugs
Zhibitai is a compound preparation of monascus and traditional Chinese medicine (i.e.,
hawthorn, alisma, and atractylodes). The most commonly used dose is 0.24–0.48 g twice
per day. This compound has mild-to-moderate cholesterol-reducing functions.[85],[86]
This drug has few adverse reactions.
Policosanol is a mixture containing 8 types of advanced aliphatic alcohol purified
from sugarcane wax. The most commonly used dose is 10–20 mg/day. Its lipid-lowering
effect is slow, and rare but adverse reactions are known.[87],[88]
10.2
Major TG-lowering drugs
Three major TG-lowering drugs exist: fibrates, niacin, and high-purity fish oil preparations.
10.2.1
Fibrates
Fibrates reduce serum TG levels and increase HDL-C levels through the activation of
peroxisome proliferator activated receptor-α (PPARα) and lipoprotein lipase (LPL).[89]–[93]
The most commonly used fibrates include fenofibrate tablets 0.1 g three times per
day, micronized fenofibrate 0.2 g once per day, gemfibrozil 0.6 g twice per day, and
bezafibrate 0.2 g three times per day. The most common adverse reactions are similar
to those of statins, including liver, muscle, and kidney toxicities. The incidence
rates of increased serum creatine kinase and ALT levels are both < 1%. Meta-analyses
of clinical trial results have shown that fibrates can reduce the risk of cardiovascular
events in people with high TG combined with low HDL-C by approximately 10%. These
drugs primarily reduce nonfatal myocardial infarction and coronary revascularization,
but they do not significant affect cardiovascular mortality, fatal myocardial infarction,
or stroke.[90]–[92]
10.2.2
Niacin
Niacin, also known as vitamin B3, is an essential vitamin in the human body. Niacin
can decrease TC, LDL-C, and TG as well as increase HDL-C in large doses. Its lipid-
lowering function is associated with the inhibition of hormone-sensitive lipase activities
in adipose tissue, the reduction of free fatty acid entry into the liver, and the
decease of VLDL secretion. Niacin has two formulation types: general and sustained-releasing.
The sustained-releasing formulation is more commonly used. The most commonly used
dose of sustained-releasing tablets is 1–2 g once per day. Starting with a small dose
(0.375–0.5 g/day) before going to bed is recommended. After four weeks, the dose gradually
increases to the commonly used maximum dose. The most common adverse reaction is facial
flushing. Other reactions include liver damage, hyperuricemia, hyperglycemia, acanthosis,
and gastrointestinal discomfort. Niacin is prohibited for patients with chronic active
liver disease, active peptic ulcer, or severe gout. The results of a meta-analysis
of early clinical trials showed that whether used alone or as a combined application
with other lipid-lowering drugs, niacin improves cardiovascular prognosis, reduces
the risk of cardiovascular events by 30%, and reduce the risk of coronary events by
25%.[94] Because clinical studies concerning the combination of niacin based on statins
suggest that no cardiovascular protective function exists compared with using statins
alone,[95],[96] niacin is being phased out of the lipid- lowering drug market in many
European and American countries.
10.2.3
High-purity fish preparations
The main ingredient of fish oil is n-3 fatty acid (i.e., ω-3 fatty acids). The common
dose is 0.5–1.0 g three times per day. Fish oil is primarily used to treat hypertriglyceridemia.[97]–[99]
Adverse reactions such as digestive tract symptoms are rare, and their incidence is
approximately 2%–3%. A few patients have mild increases of transaminases or creatine
kinase; a bleeding tendency is sometimes observed. An early clinical study showed
that high-purity fish oil preparations reduce the risk of cardiovascular events;[100]
however, subsequent clinical trials did not confirm this result.[101],[102]
10.3
New types of lipid-lowering drugs
Three new types of lipid-lowering drugs have recently been approved for clinical applications
in other countries.
10.3.1
Microsomal triglyceride transfer protein inhibitors
Lomitapide (brand name, Juxtapid) was approved for the market by the US Food and Drug
Administration (FDA) in 2012. It is primarily used to treat HoFH. Lomitapide can reduce
LDL-C by approximately 40%. This drug has higher adverse reaction rates, and the major
presentations are an increase of transaminases or fatty liver.[103],[104]
10.3.2
Apolipoprotein B100 synthesis inhibitors
Mipomersen is a second-generation anti-sense oligonucleotide. In 2013, the FDA approved
it for use alone or combined with other lipid-lowering drugs to treat HoFH. The action
mechanism is an anti-sense oligonucleotide that targets the transcription of Apo B
messenger ribonucleic acid (mRNA) to reduce VLDL synthesis and secretion and LDL-C
levels. This drug can reduce LDL-C levels by 25%. The most common adverse reaction
is an injection site reaction including local rash, swelling, itching, and pain. Most
adverse reactions are mild to moderate.[105]
10.3.3
PCSK9 inhibitor
PCSK9 is a secretory serine protease synthesized by the liver that can bind to the
LDL-C receptor to cause its degradation, thereby reducing the clearance of serum LDL-C
via the LDL-C receptor. Through the inhibition of PCSK9, LDL-C receptor degradation
can be blocked to promote LDL-C clearance. Among PCSL09 inhibitors, the development
PCSK9 monoclonal antibodies is the most rapid, and additional studies exist on alirocumab,
evolocumab, and bococizumab. These study results show that whether used alone or combined
with statins, PCSK9 inhibitors significantly reduce serum LDL-C levels and improve
other blood lipid indicators including HDL-C and Lp (a). The European Medicines Agency
and the US FDA have already approved two injection-type PCKS9 inhibitors (evolocumab
and alirocumab) for the market. Preliminary clinical study results indicate that PCSK9
inhibitors can reduce LDL-C and cardiovascular events by 40%–70%.[106],[107] Currently,
no reports regarding severe or life-threatening adverse effects have been published.[108]
This drug is still in the clinical trial stage in China.
10.4
Combined application of lipid-lowering drugs
The combined application of lipid-lowering drugs represents a trend of intervention
measures for dyslipidemia. The advantage of a combined application is to increase
the goal attainment rate of blood lipid control and simultaneously reduce the incidence
of adverse reactions. Statin functions have been recognized; few adverse reactions
are known that can reduce overall mortality. The combined lipid-lowering programs
are primarily composed of statins and other types of lipid-lowering drugs with different
action mechanisms. Different programs exist for the application of drug combinations
targeting the different action mechanisms of lipid-lowering drugs.
10.4.1
Combined application of statins and ezetimibe
Two types of drugs can individually influence cholesterol synthesis and absorption
to produce excellent synergistic effects. Combined treatment can reduce serum LDL-C
based on statin therapy by approximately 18%, but it does not increase the adverse
reactions of statins.[109]–[111] Many clinical trials have observed that ezetimibe
combined with different types of statins shows excellent lipid-lowering effects.[110],[112],[113]
The IMPROVE-IT and SHARP studies independently showed that the administration of combined
statins and ezetimibe in people with high-risk ASCVD and patients with CKD reduces
the risk of cardiovascular events.[41],[81] People whose cholesterol levels do not
reach the target after a medium-intensity statin therapy or who show intolerance should
consider medium-to-low intensity statins combined with ezetimibe therapy (Class I
recommendation (Level B evidence).
10.4.2
Combined application of statins and fibrates
The combination of these two drugs effectively reduces LDL-C and TG levels, increases
HDL-C levels, and reduces sLDL-C. Fibrates include fenofibrate, gemfibrozil, and bezafibrate;
of these compounds, fenofibrate has been the most studied and is associated with the
most sufficient evidence.[114] Previous studies have suggested that the combined application
of statins and fenofibrate increases cardiovascular benefits among patients with high
TG combined with low HDL-C.[115] Fenofibrate is applicable for patients with severe
hypertriglyceridemia with or without mixed hyperlipidemia of low HDL-C levels, especially
for those with accompanied dyslipidemia, diabetes, and metabolic syndrome and high-risk
cardiovascular patients who show poor control of their TG or HDL-C levels after statin
therapy. Because the metabolic pathways of statins and fibrates are similar, they
both have the possibility of damaging the liver function and risk myositis and myopathy.
The chances of an adverse reaction during combined application can increase. Therefore,
the safety of the combined application of statins and fibrates should be highly focused.
Gemfibrozil combined with statins show relatively higher risks of myopathy. In the
beginning of a combined application, small doses should be used via the administration
of fibrates in the morning and the administration of statins at night to avoid significant
increases in the blood drug concentration. In addition, muscle enzymes and liver enzymes
should be monitored closely. If adverse reactions occur, then the dose of statins
can be gradually increased.
10.4.3
Combined application of statins and PCSK9 inhibitors
Although PCSK9 inhibitors are still not on the Chinese market, the combined application
of statins and PCSK9 inhibitors has already become a method for treating patients
with severe dyslipidemia, especially those with FH, in Europe and America. This treatment
can cause greater reductions in LDL-C levels and increase goal attainment rates compared
with other single drug treatments. Patients with FH, especially those with HoFH, treated
with the largest dose of lipid-lowering drugs (e.g., statins+ezetimibe) and lifestyle
modification as well as patients with ASCVD and LDL-C levels > 2.6 mmol/L can also
use PCSK9 inhibitors, constituting the combined application of three lipid-lowering
drugs with different action mechanisms.
10.4.4
Combined application of statins and n-3 fatty acids
The combined application of statins and fish oil preparation n-3 fatty acids can be
used to treat mixed hyperlipidemia without increasing adverse reactions. Because taking
larger doses of n-3 polyunsaturated fatty acids has a bleeding risk and increases
calorie intake in obese patients with diabetes, long-term application is not appropriate.
Whether this combination can reduce cardiovascular events is currently under investigation.
11
Other measures for dyslipidemia treatment
11.1
Lipoprotein-plasma exchange
Highlights: Lipoprotein-plasma exchange, liver transplantation, partial ileal bypass
surgery, and portacaval shunt are used as adjuvant treatment measures for patients
with FH. The effect of lipoprotein-plasma exchange has been recognized.
Lipoprotein-plasma exchange is an important adjuvant treatment measure for patients
with FH,[116] especially for those with HoFH. This treatment can reduce LDL-C levels
by 55%–70%. Long-term treatment can cause a reduction of skin xanthomas. The best
treatment frequency is once each week. Currently, however, treatments are typically
performed once every two weeks. Lipoprotein-plasma exchange can be persistently performed
during pregnancy. This treatment measure is expensive, time-consuming, and risks infection.
Adverse reactions include hypotension, abdominal pain, nausea, hypocalcemia, iron-deficiency
anemia, and allergic reaction. However, with the development of science, technology,
and materials, the incidence of relevant adverse reactions has already decreased.
11.2
Liver transplantation and other surgical treatments
Liver transplantation can significantly improve LDL-C levels. Although simple liver
transplantation or liver transplantation combined with heart transplantation is a
successful treatment strategy, many problems exist including many post-transplantation
complications, high mortality rates, a lack of donors, and the lifetime administration
of immunosuppressive agents. Therefore, this treatment is rarely performed in clinical
practice. Although partial ileal bypass surgery and portacaval shunt are not recommended,
they should be considered when more effective treatment is lacking for patients with
severe HoFH.[116]
12
Management of dyslipidemia in special populations
12.1
Diabetes
The major presentations of diabetes combined with dyslipidemia are increased TG, decreased
HDL-C, and increased or normal LDL-C.[117] Lipid-lowering treatment can significantly
reduce the risk of developing cardiovascular events in patients with diabetes.[61]
The target level of LDL-C should be confirmed based on the severity of cardiovascular
risks.[118] Patients with diabetes aged 40 years or older should control their serum
LDL-C levels below 2.6 mmol/L (100 mg/dL) and maintain their target values of HDL-C
above 1.0 mmol/L (40 mg/dL). The principle of dyslipidemia treatment in patients with
diabetes follows the ASCVD risk assessment flow chart (Figure 1) for intervention
management. According to the features of dyslipidemia, the preferred choice is statin
therapy. If patients have combined high TG levels or do not have combined low HDL-C
levels, a combination application of statins and fibrates can be used.
12.2
Hypertension
For patients with hypertension and dyslipidemia, lipid-lowering treatments should
be applied to determine lipid-lowering target values according to different risk levels
(Figure 1). Lipid-lowering treatments enable most patients with hypertension to obtain
adequate benefits. The results are often more prominent with regard to the reduction
of coronary heart disease events.[66] Therefore, the hypertension guidelines recommend
that patients with hypertension and medium risk should initiate statin therapy. The
newly released HOPE-3 study results suggest that statin therapy significantly reduces
cardiovascular events for people at medium risk.[119],[120] For the subgroup population
with systolic pressure >143.5 mmHg, the combined application of statins and antihypertensive
drugs reduces cardiovascular risks more significantly.
12.3
Metabolic syndrome
Metabolic syndrome is a group of clinical conditions that combine the development
of obesity, high blood glucose (sugar regulation impairment or diabetes), hypertension,
and dyslipidemia (hypertriglyceridemia, HDL-C hypolipidemia, or both). One feature
is the combination of interrelated risk factors in the body metabolism of the same
individual. These factors directly promote ASCVD development and increase the risk
of developing type 2 diabetes. Some evidence indicates that patients with metabolic
syndrome are most likely to develop cardiovascular disease. Compared with people without
metabolic syndrome, their risks for developing cardiovascular disease and type 2 diabetes
are significantly increased.
The current cutoff points for determining the hyperglycemia, hypertension, and dyslipidemia
aspects of metabolic syndrome were reached via a worldwide consensus. However, the
core indicator of metabolic syndrome, obesity (especially central obesity), has different
diagnostic criteria. The diagnostic criteria of metabolic syndrome formulated based
on study evidence taken from the Chinese population should include three or more of
the following items: (1) Central obesity/abdominal obesity: a waist circumference
for men of ≥ 90 cm and that for women of ≥ 85 cm; (2) Hyperglycemia: fasting blood
glucose ≥ 6.10 mmol/L (110 mg/dL) or 2-h blood glucose after glycemic load ≥ 7.80
mmol/L (140 mg/dL) or patients with confirmed diabetes who have received treatment;
(3) Hypertension: blood pressure ≥ 130/85 mmHg or patients with hypertension who have
received treatment; (4) Fasting TG ≥ 1.7 mmol/L (150 mg/dL); and (5) Fasting HDL-C
< 1.0 mmol/L (40 mg/dL).
The major goal of metabolic syndrome management is to prevent ASCVD and type 2 diabetes.
Patients who already have ASCVD should seek to prevent cardiovascular events. Active
and sustained lifestyle interventions are important measures to achieve these treatment
goals. In principle, lifestyle treatments should be initiated first. If these goals
cannot be achieved, then corresponding drug treatments should be adopted to target
each component. The treatment goals for dyslipidemia in metabolic syndrome are LDL-C
< 2.6 mmol/L (100 mg/dL), TG < 1.7 mmol/L (150 mg/dL), and HDL-C ≥ 1.0 mmol/L (40
mg/dL).
12.4
CKD
CKD is usually accompanied by dyslipidemia and can promote the development of ASCVD.
No clinical study has investigated the LDL-C treatment goal of patients with CKD.
Under the premise of tolerance, patients with CKD are advised to receive statin therapy.
The treatment goals for patients with mild-to-moderate CKD are LDL-C < 2.6 mmol/L
and non-HDL-C < 3.4 mmol/L; those for patients with severe CKD and CKD combined with
hypertension or patients with diabetes are LDL-C < 1.8 mmol/L and non-HDL-C < 2.6
mmol/L. Medium-intensity statin therapy is recommended. When necessary, cholesterol
absorption inhibitors are combined. For patients with end-stage renal disease (ESRD)
and those receiving hemodialysis, the risks and benefits of cholesterol-lowering treatments
should be assessed carefully. Drug selection and the setting of the LDL-C goal should
be personalized.
Patients with CKD represent a population at high risk for statin-induced myopathy,
especially when renal function has shown a progressive decline or the glomerular filtration
rate (GFR) is < 30 mL/min per 1.73 m2. In addition, the risk of disease development
is closely associated with the statin dosage; therefore, the administration of large
doses should be avoided. When LDL-C cannot reach the target level after treatment
with medium-intensity statins, combination therapy with ezetimibe is recommended.[81]
Fibrate drugs can increase creatinine levels; when combined with statins among patients
with moderate-to-severe CKD, the risk of myopathy might be increased.
12.5
FH
FH is an autosomal dominant hereditary cholesterol metabolism disorder. The pathogenic
mechanism of FH is the functional genetic mutations on the LDL-C receptor, and a small
number of cases are caused by functional mutations on Apo B or PCSK9. The newly discovered
mutations on the LDL-C receptor modulator gene also explain the development of FH.
The prominent clinical manifestations are the significant increase of serum LDL-C
levels and early-onset coronary heart disease (myocardial infarction or angina pectoris).
According to dominant genetic characteristics, the clinical phenotypes of FH are divided
into the homozygous type (HoFH) and the heterozygous type (HeFH). Cholesterol level
screening shows that the serum TC level of HeFH is usually > 8.5 mmol/L (328 mg/dl),
and the serum TC level of HoFH is usually >13.5 mmol/L (521 mg/dl). Left untreated,
HeFH patients usually develop cardiovascular disease after 40 years (men) or 50 years
(women) of age. HoFH patients typically develop severe cardiovascular disease during
childhood, and the mortality rate from cardiovascular diseases in early adulthood
is 100 times higher than that among non-FH patients.
The ultimate goal of FH treatment is to reduce the risk of ASCVD and decrease the
development of fatal and disabling cardiovascular diseases.[116] One focus of treatment
is that all patients with FH (including HoFH and HeFH patients) should make enhanced
therapeutic lifestyle changes to their diets (i.e., reduce lipid and cholesterol intake
and consume a comprehensive balanced diet), exercise, and behavioral habits (i.e.,
quit smoking and reduce body weight). In addition, the management of other risk factors
(e.g., hypertension and diabetes) should be emphasized. Next, patients with FH should
adhere to long-term statin therapy beginning in adolescence to significantly reduce
the risk of ASCVD. The target level of lipid-lowering treatment is the same as that
for people at high cardiovascular risk. LDL-C is reduced by 25% in people with low
LDL-C receptors after receiving statin therapy but only by 15% in people without LDL-C
receptors. In fact, patients with FH usually require combined treatment with two or
more types of lipid-lowering drugs. Patients at very high cardiovascular risk whose
cholesterol levels still do not reach target levels after a combined lipid-lowering
treatment, especially those with disease in progress, should consider receiving lipoprotein-plasma
exchange as an adjuvant therapy.
12.6
Stroke
Whether other evidence of combined treatments with atherosclerosis exists, the use
of long-term statin therapy for patients with non-cardiogenic ischemic stroke or TIA
is recommended to reduce the risk of stroke and cardiovascular events (Class I recommendation,
Level A evidence).[63] If the baseline LDL-C level of patients is ≥ 2.6 mmol/L (100
mg/dL), then evidence of the treatment effect of statins is clear; if the baseline
level of LDL-C is < 2.6 mmol/L (100 mg/dl), then clinical evidence is lacking. For
patients with ischemic stroke resulting from intracranial large atherosclerotic stenosis
(stenosis rate: 70%–99%) or patients with TIA, the recommended target value is LDL-C
<1.8 mmol/L (70 mg/dL; Class I recommendation, Level B evidence). The long-term administration
of statin therapy is safe in general. For patients with non-cardiogenic ischemic stroke
and a history of cerebral hemorrhage or patients with TIA, statins can be reasonably
used after weighing the risks and benefits.
12.7
Elderly people
Elderly people ≥ 80 years old usually have many types of chronic diseases and take
various types of drugs. Attention should be paid to the interaction among drugs and
their adverse reactions. Most elderly patients have different degrees of liver and
kidney dysfunction; therefore, the selection of doses of lipid-lowering drugs should
be individualized. The initial dose should not be too high, and the doses of lipid-lowering
drugs should be adjusted based on treatment effects; in addition, liver and kidney
function and creatine kinase should be closely monitored. Because no randomized controlled
studies regarding the target goals of statin therapy have been conducted among elderly
patients, there are no special recommendations concerning these patients. Current
studies indicate that elderly patients with hypercholesterolemia combined with cardiovascular
disease or diabetes benefit from lipid-lowering therapy.
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