Survival benefit of CPAP therapy among dialysis patients with obstructive sleep apnea.

Abstract

Background and hypothesis: We observed lower risk of all-cause mortally among continuous positive airway pressure (CPAP) users compared to those non-users using a large polysomnography (PSG) registry. However, the effect of CPAP on mortality risk has not been examined in dialysis patents.

Methods: We studied 9841 patients with PSG performed from September 1990 to 2010 in Nakamura clinic, Okinawa. Among them, we found 195 dialysis patients: 16 (1.0%) dialysis patients with apnea hypopnea index (AHI) < 5/hour in 1665 subjects and 179 (2.2%) in 8176 obstructive sleep apnea (OSA) patients. CPAP users were defined as patients who had been on CPAP for more than one month. Patients qualified and eligible for CPAP but refused were assigned as CPAP non-users. The median observation was 6.6 years. Mortality rates were compared between CPAP users and non-users using multivariate logistic analysis adjusted for age, sex, body mass index (BMI), AHI and medical history.

Results: Among OSA dialysis patients (men 127, women 37), 116 (2.6%) were CPAP users and 48 (2.3%) were CPAP non-users. The number of deaths was 52 (29 CPAP users and 23 (CPAP non-users) during follow-up. The death rate was 25.0% for CPAP users and 47.9% for non-users. CPAP users showed better survival; hazard ratio (HR) 0.47 and 95% confidence interval (CI) of 0.27-0.81 (P = 0.007).

Conclusion: Dialysis patients with OSA showed better survival rates with the use of CPAP. Screening for OSA is recommended if patients complain of sleep problems, such as insomnia, daytime sleepiness, headache, and fatigue.