Sleep apnea is an independent risk predictor for all-cause and cardiovascular mortality in peritoneal dialysis patients

Abstract

Sleep apnea is increasingly being recognized as highly prevalent in dialysis patients. However, the prognostic implication of sleep apnea in this population is not known. We prospectively followed the clinical outcomes of continuous ambulatory peritoneal dialysis (PD) patients who were recruited into our “Sleep Apnea in PD Patients” program since the late 1990s. Baseline comprehensive overnight polysomnography was performed in 93 PD subjects [age (mean ± standard deviation): 56 ± 15 years; 52% men]. Significant sleep apnea, defined as an apnea–hypopnea index (AHI: frequency of apnea and hypopnea per hour of sleep) ≥ 15, was present in 51 subjects (55%). During a mean follow-up of 47.8 ± 27 months (range: 2.2 – 117.2 months), 30 deaths occurred (32%), of which 13 deaths (43%) were the result of cardiovascular causes. Cardiovascular mortality was 69% and 31% (p < 0.05) respectively for patients with and without sleep apnea (AHI ≥ 15) over the follow-up period. Using Kaplan–Meier analysis for the entire follow-up duration, patient survival was significantly higher in patients with a baseline AHI < 15 (71% vs. 36%, p = 0.017). Multivariate Cox regression analysis showed that the presence of significant sleep apnea was predictive of an increased all-cause mortality [hazard ratio (HR): 3.50; 95% confidence interval (CI): 1.32 to 6.76; p < 0.05] and cardiovascular death (HR: 6.1; 95% CI: 3.37 to 16.48).