Cardiovascular Implications of Diabetes, Metabolic Syndrome, Thyroid Disease, and Cardio-Oncology in Women

To assess the magnitude of the association between the National Cholesterol Education Program's Third Adult Treatment Panel Report (ATP III) definition of the metabolic syndrome and cardiovascular disease (CVD). Cox regression was used to estimate the relative risk of incident coronary heart disease (CHD) and stroke among 12,089 black and white middle-aged individuals in the Atherosclerosis Risk in Communities (ARIC) study. The metabolic syndrome was present in approximately 23% of individuals without diabetes or prevalent CVD at baseline. Over an average of 11 years of follow-up, 879 incident CHD and 216 ischemic stroke events occurred. Among the components of the metabolic syndrome, elevated blood pressure and low levels of HDL cholesterol exhibited the strongest associations with CHD. Men and women with the metabolic syndrome were approximately 1.5 and 2 times more likely to develop CHD than control subjects after adjustment for age, smoking, LDL cholesterol, and race/ARIC center (sex interaction P < 0.03). Similar associations were found between the metabolic syndrome and incident ischemic stroke. Comparison of receiver operating characteristic curves indicated that the metabolic syndrome did not materially improve CHD risk prediction beyond the level achieved by the Framingham Risk Score (FRS). Individuals without diabetes or CVD, but with the metabolic syndrome, were at increased risk for long-term cardiovascular outcomes, although statistical models suggested that most of that risk was accounted for by the FRS. Nevertheless, identification of individuals with the metabolic syndrome may provide opportunities to intervene earlier in the development of shared disease pathways that predispose individuals to both CVD and diabetes.

The prevalence of diabetes has been increasing greatly, but WHO's predicted 39% rise in the global rate of diabetes from 2000 to 2030 might be an underestimate. We aimed to assess diabetes trends in Ontario, Canada. Using population-based data, including a validated diabetes database from the province of Ontario, Canada, we examined trends in diabetes prevalence and mortality from 1995 to 2005, and incidence from 1997 to 2003, in adults aged 20 years or older. Age-adjusted and sex-adjusted diabetes prevalence increased by 69%, from 5.2% in a population of 7,908,562 in 1995 to 8.8% of 9,276,945 in 2005. Prevalence increased by 27% from 6.9% in a population of 8,457,720 in 2000 to 8.8% of 9,276,945 in 2005. Although prevalence rates have remained higher in people aged 50 years or older (7.1% of 3,675,554) than in those aged 20-49 years (3.5% of 5 601 391), rates increased to a greater extent in the younger population (94%vs 63%, p<0.0001). A 31% increase occurred in yearly incidence over 6 years, from 6.6 per 1000 in 1997 to 8.2 per 1000 in 2003. The adjusted mortality rate in people with diabetes fell by 25% from 1995 to 2005. The prevalence of diabetes in Ontario, Canada increased substantially during the past 10 years, and by 2005 already exceeded the global rate that was predicted for 2030. This increase in prevalence is attributable to both rising incidence and declining mortality. Effective public-health interventions aimed at diabetes prevention are needed, as well as improved resources to manage the greater number of people living longer with the disease.

Different definitions of the metabolic syndrome have been proposed. Their value in a clinical setting to assess cardiovascular disease (CVD) risk is still unclear. We compared the definitions proposed by the National Cholesterol Education Program Adult Treatment Panel III (NCEP), World Health Organization (WHO), European Group for the Study of Insulin Resistance (EGIR), and American College of Endocrinology (ACE) with respect to the prevalence of the metabolic syndrome and the association with 10-year risk of fatal and nonfatal CVD. The Hoorn Study is a population-based cohort study. The present study population comprised 615 men and 749 women aged 50 to 75 years and without diabetes or a history of CVD at baseline in 1989 to 1990. The prevalence of the metabolic syndrome at baseline ranged from 17% to 32%. The NCEP definition was associated with about a 2-fold increase in age-adjusted risk of fatal CVD in men and nonfatal CVD in women. For the WHO, EGIR, and ACE definitions, these hazard ratios were slightly lower. Risk increased with the number of risk factors. Elevated insulin levels were more prevalent in subjects with multiple risk factors, but metabolic syndrome definitions including elevated insulin level were not more strongly associated with risk. The metabolic syndrome, however defined, is associated with an approximate 2-fold increased risk of incident cardiovascular morbidity and mortality in a European population. In clinical practice, a more informative assessment can be obtained by taking into account the number of individual risk factors.