Effect of exercise interventions for sleep quality in patients with chronic kidney disease: a systematic review and meta-analysis

Introduction Sleep disorder is a common and unpleasant symptom in patients with chronic kidney disease (CKD), bringing a heavy burden on the patients and families. As a non-pharmacological therapy, exercise interventions are widely recommended for CKD patients. However, whether exercise can improve overall sleep quality in such a population remains ambiguous. The systematic review and meta-analysis aimed to evaluate the effect of exercise interventions on sleep quality in CKD patients. Methods PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched from inception to April 22, 2022. A randomized controlled trial (RCT) added an exercise intervention to conventional treatment/usual care to assess the effect on sleep quality in CKD patients. Two authors independently selected literature, extracted data, assessed the risk of bias using the Cochrane risk of bias tool 2, and assessed the certainty of the evidence using the Grading of Recommendations, Assessment, Development, and Evaluation. The outcome was analyzed using a random-effect model using the Hartung-Knapp-Sidik-Jonkman method as a standardized mean difference (SMD). Additional statistical analysis includes the Egger regression test, subgroup analysis, sensitivity analysis, and meta-regression. Results Nineteen articles (20 RCTs) enrolling 989 patients with CKD were included. The pooled SMD suggested favorably associated exercise interventions (SMD - 0.16; 95% CI - 0.62 to 0.31; very low evidence) with substantial heterogeneity (I-2 = 87%). Subgroup analyses demonstrated that SMD for sleep quality favored moderate intensity and aerobic exercise, no matter the time, but not statistically significant. Meta-regression showed that the effect size of exercise interventions on sleep quality was not associated with the total sample size, the proportion of males, duration of intervention, mean age, and exercise volume but was associated with baseline sleep scores. In addition, there may be an exercise threshold for the effect of exercise on sleep in CKD patients (i.e., 80 min/week). Conclusion This systematic review and meta-analysis suggest that exercise interventions may be associated with improved sleep quality in patients with CKD. However, high heterogeneity and a small effect size limit this result. More studies and standardized reporting of exercise intervention characteristics should be conducted in the future to strengthen the most convincing evidence in this field.