Sleep Patterns, Symptoms, and Mortality in Hemodialysis: A Prospective Cohort Study.

Rationale & Objective: While sleep disorders are common in patients treated with hemodialysis, the impact of sleep patterns on survival is not well defined. We thus examined the association of specific sleep patterns with mortality in this population.

Study Design: An observational cohort study.

Setting & Population: In-center hemodialysis patients from the multicenter prospective NIH Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease (MADRAD) cohort.

Exposure: Sleep patterns ascertained using protocolized sleep surveys from March 2014 to June 2019.

Outcomes: Mortality.

Analytical Approach: Cox proportional hazards models.

Results: Among 452 participants, the mean age was 55±14 years, among whom 46% were women and the median follow-up was 3.5 years. In expanded case-mix models, shorter sleep duration (≤ median of observed values) was associated with higher mortality on dialysis and nondialysis days (ref: > median): HRs (95% CIs) 1.59 (1.09-2.31) and 1.51 (1.04-2.19), respectively. Patients who reported high frequencies (often/almost always) of difficulty falling asleep, feeling unrested, fatigue/exhaustion post-dialysis, or fatigue/exhaustion on nondialysis days had higher mortality (ref: never/rarely having these symptoms): HRs (95% CIs) 1.74 (1.17-2.58), 1.69 (1.1-2.5), 2.42 (1.41-4.16), and 1.73 (1.11-2.69), respectively. Moderate to high frequency of sleeping pill use was associated with higher mortality (ref: never/rare use): HRs (95% CIs) 2.07 (1.08, 3.97) and 2.00 (1.22, 3.28) for sometimes and often/almost always using sleeping pills, respectively. Sleeping outside of the primary sleep period (intra-dialytic sleeping and napping) was not associated with worse survival. However, patients reporting frequent apnea or restless legs syndrome had higher mortality.

Limitations: Potential recall bias, residual confounding, absence of time-varying observations, and limitations in generalizability.

Conclusions: In a well-characterized prospective multicenter hemodialysis cohort, patients who reported shorter sleep duration, sleeping difficulty or feeling unrested, moderate to frequent sleeping pill consumption, and sleep disorders (apnea and restless legs) had a higher mortality risk.