The effects of melatonin on sleep-wake rhythm of daytime haemodialysis patients: a randomized, placebo-controlled, cross-over study (EMSCAP study)

Abstract

Aim: The aim of this study was to investigate the effects of exogenous melatonin on sleep-wake rhythm in haemodialysis patients.

Methods: The study design is a randomized, double-blind, placebo-controlled, cross-over study of 3 x 6 weeks melatonin 3 mg at 22.00 h every night. Haemodialysis patients were asked to fill out a sleep questionnaire and to wear an actometer to record their sleep problems objectively. Furthermore, melatonin concentrations in saliva were sampled the night after daytime haemodialysis and the consecutive night. Actometers, the sleep questionnaire and melatonin concentrations were repeated during the study.

Results: In total, 20 patients (six female, median age 71 years) completed the investigation. On nights after daytime dialysis, objective sleep onset latency decreased significantly from a median of 44.5 (placebo) to a median of 15.5 min with melatonin (P < 0.01). Sleep efficiency increased from 67.3 to 73.1% with melatonin (P < 0.05). Actual sleep time increased from 376 min (placebo) to 388 min with melatonin (P < 0.01), and sleep fragmentation decreased from 4.5 to 3.1 (P < 0.01). Furthermore, subjective sleep parameters improved also. Patients reported less time needed to fall asleep (P < 0.05) and fewer wake periods (P < 0.05) on the nights with and without daytime dialysis and an increase in sleep time on the night of daytime dialysis (P < 0.05). Furthermore, the nocturnal melatonin rise was recovered.

Conclusion: Treatment with melatonin resulted in an improvement of subjective and objective sleep parameters, as well as a recovered nocturnal melatonin rhythm.

Trial registration: ClinicalTrials.gov NCT00404456.

Figures

Figure 1

The design of this study. The study measurements and the date of measurement are displayed

Figure 2

Displays a week's actogram of a patient, at baseline. The graph shows the movements of the wrist during night and day. All days are double plotted, as on all lines two consequent 24-h periods are shown. The black lines reflect the movement of the wrist. The yellow areas represent the light input on the actiwatch of the patient. This patient dialysed on Tuesday, Thursday and Saturday afternoon. As can be seen, there are often low light conditions during the day. Daytime napping does occur based on the absence of wrist movements, which can indicate sleep

Figure 3

Displays the mean melatonin concentration measured in saliva on the day of dialysis and the consecutive day. The horizontal axis reflects the time of day in hours and the vertical axis reflects the melatonin concentration in saliva in pg ml−1. Lines with open bullets represent the measurements before treatment. Lines with closed bullets represent the measures after treatment. Vertical lines at the measuring points represent the standard deviation error bars. Before treatment: night following dialysis (); Before treatment: night after non-dialysis day (); After treatment: night following dialysis (); After treatment: night after non-dialysis day ()