Background: Inadequate physical activity is related to impaired cardiovascular reserve capacity and higher mortality in early years. While cardiovascular disease (CVD) is the leading cause of death in chronic kidney disease (CKD) populations, the effect of regular exercise on this group is unclear.
Objectives: To assess the effects and safety of regular exercise in non-dialysis CKD populations with regard to physical fitness, cardiovascular and renal outcomes.
Methods: We searched for randomized controlled trials (RCTs) that addressed the effects of regular exercise in non-dialysis CKD patients in CENTRAL, Embase, PubMed, Web of Science, and four Chinese databases (CBM, CNKI, CQVIP, WANFANG), up to June 2015. Study selection, data extraction and scientific quality assessment were performed independently by two researchers. Continuous outcome data were presented as mean difference (MD) or standardized mean difference (SMD) with 95% confidence intervals (CI).
Results: We identified 14 RCTs with 473 participants. Types of exercise included aerobic, mixed and resistance training. Most studies exercised three times per week at moderate intensity, for 20-60 minutes per session, over 3-18 months. Thirty-six per cent of studies were classified as being at low risk of bias, another 36% as being at unclear risk, and 28% as high risk. Regular exercise showed benefits in cardiovascular function (mean blood pressure, 1 RCT, 27 participants: MD -7.99 mmHg, 95% CI -11.41 to -4.56; pulse wave velocity, 1 RCT, 18 participants: MD -2.6 m/s, 95% CI -4.46 to -0.74) and physical fitness (aerobic capacity, 10 RCTs, 249 participants: MD 2.29 mL/kg/min, 95% CI 1.18 to 3.39; walking capacity, 4 RCTs, 128 participants: MD 31.89 m, 95% CI 8.02 to 55.77; muscular strength, 1 RCT, 26 participants: MD 121 kg, 95% CI 78.74 to 163.26). There was insufficient evidence on outcomes of kidney function (glomerular filtration rate and serum creatinine). None of trials reported the incidence of CVD and mortality.
Conclusions: Regular exercise may reduce cardiovascular risks by improving cardiovascular function and fitness. Effect on long-term outcomes needs to be tested by future studies.