Regular Exercise Can Boost Health in Patients With CKD

Laura Newman

October 07, 2011

October 7, 2011 — Declining physical fitness is common among people with chronic kidney disease (CKD), but a new meta-analysis published online October 5 in the Cochrane Database of Systematic Reviews provides evidence showing that regular exercise can significantly improve physical fitness, cardiovascular measures, some nutritional parameters, and health-related quality of life. The results apply to patients across the spectrum, from those with early chronic kidney disease lasting more than 3 months, to those on dialysis, to those who received kidney transplants.

Susanne Heiwe, PhD, and Stefan H. Jacobson, MD, PhD, from the Department of Medicine and Clinical Sciences, Karolinska Institutet, Stockholm, Sweden, reviewed the evidence. They write: "[I]n adults with CKD the following exercise regimen is recommended: four to six months supervised, regular (three sessions/week), high intensity mixed cardiovascular and resistance training lasting 30 to 90 minutes. To maintain this peak effect the patient has to continue with the regular exercise training intervention."

Improvement in several areas of physical fitness, particularly aerobic capacity (24 studies, 847 participants; standardized mean difference (SMD), −0.56; 95% confidence interval [CI], −0.70 to −0.42) and walking capacity (7 studies, 191 participants; SMD, −0.36; 95% CI, −0.65 to −0.06) was striking.

Cardiovascular benefits were also demonstrated for the following dimensions:

  • resting diastolic blood pressure: 11 studies, 419 participants (mean difference method [MD], 2.32 mm Hg; 95% CI, 0.59 - 4.05 mm Hg);

  • resting systolic blood pressure: 9 studies, 347 participants (MD, 6.08 mm Hg; 95% CI, 2.15 - 10.12 mm Hg);

  • heart rate, 11 studies, 229 participants (MD, 6 bpm; 95% CI, 10 - 2 bpm);

  • some nutritional parameters:

    • albumin: 3 studies, 111 participants (MD, −2.28 g/L; 95% CI, −4.25 to 0.32 g/L);

    • prealbumin: 3 studies, 111 participants (MD, −44.02 mg Cl; 95% CI, −71.52 to 16.53 mg Cl;

    • energy intake: 4 studies, 97 participants (SMD, −0.47; 95% CI, −0.88 to −0.05);

  • and health-related quality of life.

Statistically significant improvement in high-density lipoprotein cholesterol was shown with regular exercise, regardless of type, intensity, length of intervention, or supervision (4 studies, 166 participants; MD −0.14 mmol/L; 95% CI, −0.23 to −0.04 mmol/L; P = .005), but there were no significant changes in triglycerides, total cholesterol, or fasting blood glucose.

The authors searched the Cochrane Renal Group's specialized register, which encompasses studies in all languages. They selected reviews of any randomized controlled trial that enrolled adults with CKD or kidney transplant in physical exercise programs for a minimum of 8 weeks. They excluded studies involving interventions that lasted less than 8 weeks, those only advising an increase in physical activity, and studies in which co-interventions were not applied or given to both groups.

Forty-five studies that randomly assigned 1863 patients to groups were included in this review. Of these, 32 satisfied criteria for meta-analysis. Interventions in those studies covered a range of exercise regimens, including cardiovascular training, mixed cardiovascular and resistance training, resistance-only training, and yoga. To be included in the review, the exercise regimen had to be at least 20 minutes long, but the investigators included studies on both high- and low-intensity exercise and studies on both supervised and unsupervised regimens

Of 14 studies reporting compliance with exercise, 11 studies found high compliance, 1 had moderate compliance, and none reported low compliance. Only 1 study reported exercise-induced injuries.

The investigators flagged several areas as having an insufficient research base. These include attention to muscular endurance, muscle morphology and morphometrics, physical function (such as stair climbing), other cardiovascular dimensions (eg, arrhythmias), muscle mass, systemic inflammation, level of physical activity in daily living, depression, lipids, glucose metabolism, drop-out rates, compliance, adverse events, and mortality. In addition, the authors recommend study of the effects of exercise vs drug treatment (eg, statins), or as a compliment to statins. The preponderance of research has addressed cardiovascular exercise, and the authors state that future research should give a high priority to assessing the effects of resistance training interventions, either alone or in combination with cardiovascular exercise training.

The authors have disclosed no relevant financial relationships.

Cochrane Database Syst Rev. Published online October 5, 2011. Abstract


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