Association of Sleep Apnea with Mortality in Patients with Advanced Kidney Disease

Background and objectives In the general population, sleep disorders are associated with mortality. However, such evidence in patients with CKD and ESKD is limited and shows conflicting results. Our aim was to examine the association of sleep apnea with mortality among patients with CKD and ESKD. Design, setting, participants, & measurements In this prospective cohort study, 180 patients (88 with CKD stage 4 or 5, 92 with ESKD) underwent in-home polysomnography, and sleep apnea measures such as apnea hypopnea index (AHI) and nocturnal hypoxemia were obtained. Mortality data were obtained from the National Death Index. Cox proportional hazard models were used for survival analysis. Results Among the 180 patients (mean age 54 years, 37% women, 39% with diabetes, 49% CKD with mean eGFR 18±7 ml/min per 1.73 m2), 71% had sleep apnea (AHI>5) and 23% had severe sleep apnea (AHI>30). Median AHI was 13 (range, 4–29) and was not significantly different in patients with advanced CKD or ESKD. Over a median follow-up of 9 years, there were 84 (47%) deaths. AHI was not significantly associated with mortality after adjusting for age, sex, race, diabetes, body mass index, CKD/ESKD status, and kidney transplant status (AHI>30: hazard ratio [HR], 1.5; 95% confidence interval [95% CI], 0.6 to 4.0; AHI >15 to 30: HR, 2.3; 95% CI, 0.9 to 5.9; AHI >5 to 15: HR, 2.1; 95% CI, 0.8 to 5.4, compared with AHI≤5). Higher proportion of sleep time with oxygen saturation Conclusions Hypoxemia-based measures of sleep apnea are significantly associated with increased risk of death among advanced CKD and ESKD.