Sleep apnea is significantly associated with increased risk of death among patients with advanced chronic kidney disease (CKD) and end-stage renal disease (ESRD), according to the results of a study published in the Clinical Journal of American Society of Nephrology.1

The prevalence of sleep apnea is significantly greater in patients with CKD than in the general population and has increased in the past 20 years along with increased rates of obesity.2

In the prospective cohort study, 88 patients with stage 4 or 5 CKD and 92 patients with ESRD underwent in-home polysomnography to obtain sleep apnea measurements. The mean patient age was 54, and 37% were women. Of the 180 patients, 71% had sleep apnea, and 23% had severe sleep apnea. The median score on the apnea hypopnea index (AHI) was 13 (ranging from 4-29) and was not significantly different in patients with advanced CKD or ESRD.1

Over a median follow-up of 9 years, there were 84 (47%) deaths. AHI was not significantly associated with mortality after adjusting for age, body mass index, CKD/ESRD status, incidence of diabetes, gender, kidney transplant status, and race. Similarly, periodic limb movement index or  sleep duration or efficiency, or periodic limb movement index were not associated with mortality.1

However, a higher proportion of sleep time with oxygen saturation <90% and lower mean oxygen saturation were significantly associated with higher mortality in adjusted analysis.1

In the adjusted analyses, every 2% decrease in mean oxygen was associated with a 60% higher death risk, and every 15% worsening in nocturnal hypoxemia was associated with a 40% increase in death risk.1

REFERENCES
  1. Jhamb M, Ran X, Abdalla H, et al. Association of sleep apnea with mortality in patients with advanced kidney disease. Clin J  Am Soc Nephrol. 2020;15(2):182-190. doi: 10.2215/CJN.07880719.  
  2. Abuyassin B, Sharma K, Ayas N, Laher I. Obstructive Sleep Apnea and Kidney Disease: A Potential Bidirectional Relationship? J Clin Sleep Med. 2015;11(8):915-24. doi: 10.5664/jcsm.4946.