Chronic kidney disease (CKD) is a worldwide public health problem. In the National
Kidney Foundation Disease Outcomes Quality Initiative guidelines it is stressed that
lifestyle issues such as physical activity should be seen as cornerstones of the therapy.
The physical fitness in adults with CKD is so reduced that it impinges on ability
and capacity to perform activities in everyday life and occupational tasks. An increasing
number of studies have been published regarding health effects of various regular
exercise programmes in adults with CKD and in renal transplant patients.
We aimed to: 1) assess the effects of regular exercise in adults with CKD and kidney
transplant patients; and 2) determine how the exercise programme should be designed
(e.g. type, duration, intensity, frequency of exercise) to be able to affect physical
fitness and functioning, level of physical activity, cardiovascular dimensions, nutrition,
lipids, glucose metabolism, systemic inflammation, muscle morphology and morphometrics,
dropout rates, compliance, adverse events and mortality.
We searched the Cochrane Renal Group's specialised register, CENTRAL, MEDLINE, EMBASE,
CINAHL, Web of Science, Biosis, Pedro, Amed, AgeLine, PsycINFO and KoreaMed. We also
handsearched reference lists of review articles and included studies, conference proceeding's
abstracts. There were no language restrictions.Date of last search: May 2010.
We included any randomised controlled trial (RCT) enrolling adults with CKD or kidney
transplant recipients undergoing any type of physical exercise intervention undertaken
for eight weeks or more. Studies using less than eight weeks exercise, those only
recommending an increase in physical activity, and studies in which co-interventions
are not applied or given to both groups were excluded.
Data extraction and assessment of study and data quality were performed independently
by the two authors. Continuous outcome data are presented as standardised mean difference
(SMD) or mean difference (MD) with 95% confidence intervals (CI).
Forty-five studies, randomising 1863 participants were included in this review. Thirty
two studies presented data that could be meta-analysed. Types of exercise training
included cardiovascular training, mixed cardiovascular and resistance training, resistance-only
training and yoga. Some studies used supervised exercise interventions and others
used unsupervised interventions. Exercise intensity was classed as 'high' or 'low',
duration of individual exercise sessions ranged from 20 minutes/session to 110 minutes/session,
and study duration was from two to 18 months. Seventeen per cent of studies were classed
as having an overall low risk of bias, 33% as moderate, and 49% as having a high risk
of bias.The results shows that regular exercise significantly improved: 1) physical
fitness (aerobic capacity, 24 studies, 847 participants: SMD -0.56, 95% CI -0.70 to
-0.42; walking capacity, 7 studies, 191 participants: SMD -0.36, 95% CI-0.65 to -0.06);
2) cardiovascular dimensions (resting diastolic blood pressure, 11 studies, 419 participants:
MD 2.32 mm Hg, 95% CI 0.59 to 4.05; resting systolic blood pressure, 9 studies, 347
participants: MD 6.08 mm Hg, 95% CI 2.15 to 10.12; heart rate, 11 studies, 229 participants:
MD 6 bpm, 95% CI 10 to 2); 3) some nutritional parameters (albumin, 3 studies, 111
participants: MD -2.28 g/L, 95% CI -4.25 to -0.32; pre-albumin, 3 studies, 111 participants:
MD - 44.02 mg/L, 95% CI -71.52 to -16.53; energy intake, 4 studies, 97 participants:
SMD -0.47, 95% CI -0.88 to -0.05); and 4) health-related quality of life. Results
also showed how exercise should be designed in order to optimise the effect. Other
outcomes had insufficient evidence.
There is evidence for significant beneficial effects of regular exercise on physical
fitness, walking capacity, cardiovascular dimensions (e.g. blood pressure and heart
rate), health-related quality of life and some nutritional parameters in adults with
CKD. Other outcomes had insufficient evidence due to the lack of data from RCTs. The
design of the exercise intervention causes difference in effect size and should be
considered when prescribing exercise with the aim of affecting a certain outcome.
Future RCTs should focus more on the effects of resistance training interventions
or mixed cardiovascular- and resistance training as these exercise types have not
been studied as much as cardiovascular exercise.