Effects of nocturnal hemodialysis on melatonin rhythm and sleep-wake behavior: an uncontrolled trial

Background: End-stage renal disease and its treatment are associated with sleep disturbances such as deterioration of the circadian sleep-wake pattern. Melatonin rhythm, which has an important role in this pattern, is disturbed. The nocturnal melatonin surge is absent in this population. Whether nocturnal in-center hemodialysis changes melatonin and sleep-wake rhythms is unknown.
Study Design: A nonrandomized uncontrolled trial. Patients served as their own controls.
Setting & Participants: Thirteen daytime hemodialysis patients (median age, 58 years; 5 women) from our hospital receiving conventional daytime hemodialysis 3 times weekly for 3 to 4 hours each session.
Interventions: Six months of treatment with nocturnal in-center dialysis 4 nights/wk with 8-hour sessions.
Outcomes & Measurements: At baseline, while still on conventional hemodialysis therapy, polysomnography was performed, sleep questionnaires were filled out, and melatonin concentration in saliva was obtained. After 6 months of in-center nocturnal hemodialysis, all measurements were repeated.
Results : After 6 months of in-center nocturnal hemodialysis, polysomnography showed significant improvements in sleep efficiency (P = 0.05) and stage 3/4 sleep (P = 0.03) in comparison to t = 0. Trends in improvement of rapid-eye-movement sleep, awake time, and oxygen saturation were seen after 6 months of in-center nocturnal hemodialysis therapy. Sleep questionnaires showed a trend in improved sleep quality and daytime function. Patients were less exhausted during the daytime. The nocturnal melatonin surge was partially restored.
Limitations: Small sample size and a nonrandomized uncontrolled study design.
Conclusions: Patients after 6 months of in-center nocturnal hemodialysis had significant improvements in subjective and objective sleep parameters and partially restored nocturnal melatonin rhythm.