Long-term effects of melatonin on quality of life and sleep in haemodialysis patients (Melody study): a randomized controlled trial

AimThe disturbed circadian rhythm in haemodialysis patients results in perturbed sleep. Short term melatonin supplementation has alleviated these sleep problems. Our aim was to investigate the effects of long-term melatonin supplementation on quality of life and sleep. MethodsIn this randomized double-blind placebo-controlled trial haemodialysis patients suffering from subjective sleep problems received melatonin 3mg day(-1)vs. placebo during 12 months. The primary endpoint quality of life parameter vitality' was measured with Medical Outcomes Study Short Form-36. Secondary outcomes were improvement of three sleep parameters measured by actigraphy and nighttime salivary melatonin concentrations. ResultsSixty-seven patients were randomized. Forty-two patients completed the trial. With melatonin, no beneficial effect on vitality was seen. Other quality of life parameters showed both advantageous and disadvantageous effects of melatonin. Considering sleep, at 3 months sleep efficiency and actual sleep time had improved with melatonin compared with placebo on haemodialysis days (difference 7.6%, 95% CI 0.77, 14.4 and 49min, 95% CI 2.1, 95.9, respectively). At 12 months none of the sleep par ConclusionsThe high drop-out rate limits the strength of our conclusions. However, although a previous study reported beneficial short term effects of melatonin on sleep in haemodialysis patients, in this long-term study the positive effects disappeared during follow up (6-12 months). Also the quality of life parameter, vitality, did not improve. Efforts should be made to elucidate the mechanism responsible for the loss of effect with chronic use.