association of sleep duration, symptoms, and disorders with mortality in adults with chronic kidney disease

Abstract

In general populations, short and long sleep duration, poor sleep quality, and sleep disorders have been associated with increased risk of death. We evaluated these associations in individuals with CKD. Methods: This was a prospective cohort study of 1452 NHANES 2005 to 2008 participants with CKD. CKD was defined by estimated glomerular filtration rate <60 ml/min per 1.73 m2 or urine albumin-to-creatinine ratio ≥30 mg/g. Sleep duration, sleep symptoms (difficulty falling asleep, difficulty staying asleep, daytime sleepiness, and nonrestorative sleep), and sleep disorders (restless legs syndrome and sleep apnea) were self-reported. Vital status was determined using NHANES mortality linkage through December 31, 2011. Results: In this cohort, the mean age was 61 years, 58% were women, and 75% non-Hispanic white. During 4.4 years of median follow-up, we observed 234 deaths, of which 75 were due to cardiovascular causes. In multivariable analyses, compared with individuals who reported 7 to 8 hours of sleep, HR (95% CI) for all-cause mortality for sleep duration <7 hours and >8 hours were 1.50 (1.08–2.10) and 1.36 (0.89–2.08), respectively. The corresponding HR (95% CI) for cardiovascular mortality were 1.56 (0.72–3.37) and 1.56 (0.66–3.65). Nonrestorative sleep and restless legs syndrome were associated with increased risk for all-cause mortality (HR, 1.63 [95% CI, 1.13–2.35], and HR, 1.69 [95% CI, 1.04–275], respectively). Discussion: In adults with CKD, short sleep duration, nonrestorative sleep, and restless legs syndrome are associated with increased risk of death. These findings underscore the importance of promoting adequate sleep in patients with CKD, and the need for future studies evaluating the impact of sleep interventions in this population.