Bidirectional association of sleep disorders with chronic kidney disease: a systematic review and meta-analysis.

Background: Published studies have suggested a link between chronic kidney disease (CKD) and sleep disorders, although the exact nature of this association has not been uniformly described. Clarifying this relationship may facilitate evidence-based interventions that address the interplay between these disease entities. Such interventions could prevent obstructive sleep apnea (OSA) from worsening CKD and improve the quality of life for CKD patients by reducing the risk of developing OSA. Therefore, the objective of this meta-analysis is to assess the bidirectional association between sleep disorders and CKD.

Methods: Following a PROSPERO-registered protocol, three blinded reviewers conducted a systematic review of the Medline/PubMed, Embase, Cochrane Library and Cumulative Index of Nursing and Allied Health (CINAHL) databases for observational studies pertaining to the relationship between sleep disorders and CKD. A meta-analysis was conducted in risk ratios (RRs).

Results: From 63 studies (26 777 524 patients), OSA [RR 1.68; 95% confidence interval (CI) 1.45 to 1.93], albuminuria (RR 1.54; 95% CI 1.18 to 1.99), restless leg syndrome (RLS) (RR 1.88; 95% CI 1.48 to 2.38) and insomnia (RR 1.24; 95% CI 1.01 to 1.54) were significantly associated with CKD. There was a significant association between OSA (RR 1.77; 95% CI 1.56 to 2.01) with incident CKD. There was a significant association of OSA (RR 1.74; 95% CI 1.55 to 1.96), RLS (RR 1.73; 95% CI 1.32 to 2.25) and insomnia (RR 1.14; 95% CI 1.03 to 1.27) in patients with CKD compared with healthy controls. CKD was also significantly associated with incident OSA (RR 1.60; 95% CI 1.35 to 1.89).

Conclusion: The bidirectional associations of obstructive sleep apnea with CKD remained consistent across different stages of CKD, modes of diagnosis of sleep disorder and geographical region. A bidirectional association was observed between CKD and obstructive sleep apnea, RLS and insomnia. The treatment of sleep disorders may reduce the risk of CKD, and vice versa.