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

Abstract

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.

Plain Language Summary

Patients with kidney failure have a high burden of sleep disorders. However, the relationship between sleeping problems and the health of patients treated with dialysis is not well understood. To address this knowledge gap, we examined the relationship between various types of sleep disturbances and associated symptoms with survival among a diverse cohort of patients treated with hemodialysis from the multicenter prospective NIH Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease (MADRAD) study. We found that patients who reported shorter sleep duration, sleeping difficulty or feeling unrested, moderate to frequent sleeping pill consumption, and sleep disorders such as apnea or restless legs syndrome had a higher death risk.