Nocturnal dialysis improves sleep apnea more than daytime dialysis: a meta-analysis of crossover studies

Abstract

Purpose: To systematically review the literature for articles evaluating differences in polysomnography (PSG) data when patients are on primarily daytime hemodialysis (conventional hemodialysis or continuous ambulatory peritoneal dialysis) versus nocturnal hemodialysis (nocturnal hemodialysis or nocturnal peritoneal dialysis). Then to perform a meta-analysis on the available PSG data, specifically evaluating differences in apnea hypopnea index (AHI) and mean saturation of oxygen (SpO₂) between these two groups.

Methods: Two authors systematically searched MEDLINE/Pubmed, Scopus, EMBASE, CINAHL, and Cochrane. Searches were performed through December 6, 2018.

Results: A total of four adult crossover studies (91 patients, age 50.4 ± 12.4, BMI 25.1 ± 5.3) reported PSG data. The daytime hemodialysis (DHD) and nocturnal hemodialysis (NHD) AHI decreased from 24.6 ± 18.2 to 12.6 ± 11.8 (events/hour) with a mean difference of -11.9 [95% CI -13.47, -10.37], Z score of 15.07 (P < 0.00001). The standardized mean difference was -1.35 [95% CI -2.70, 0.01]. Two studies reported mean SpO₂ changes during PSG. The DHD and NHD SpO₂ increased from 92.7 ± 2.4 to 94.7 ± 2.2 with a mean difference of 2.26 [95% CI -0.18, 4.71], Z score 1.82 (P = 0.07).

Conclusion: In the current literature, nocturnal hemodialysis improves AHI more than daytime hemodialysis. A trend towards improvement in mean SpO₂ with nocturnal dialysis was noted, but did not reach statistical significance. Consideration can be given for transitioning patients who have end stage renal disease and sleep apnea from daytime to nocturnal hemodialysis as an adjunct to other treatment modalities.

Keywords: Apnea hypopnea index; Fluid shift; Nocturnal hemodialysis; Sleep apnea.