IMPROVEMENT OF SLEEP QUALITY IN ELDERLY PEOPLE BY CONTROLLED-RELEASE MELATONIN

Melatonin, produced by the pineal gland at night, has a role in regula tion of the sleep-wake cycle. Among elderly people, even those who are healthy, the frequency of sleep disorders is high and there is an ass ociation with impairment of melatonin production. We investigated the effect of a controlled-release formulation of melatonin on sleep quali ty in 12 elderly subjects (aged 76 [SD 8] years) who were receiving va rious medications for chronic illnesses and who complained of insomnia . In all 12 subjects the peak excretion of the main melatonin metaboli te 6-sulphatoxymelatonin during the night was lower than normal and/or delayed in comparison with non-insomniac elderly people. In a randomi sed, double blind, crossover study the subjects were treated for 3 wee ks with 2 mg per night of controlled-release melatonin and for 3 weeks with placebo, with a week's washout period. Sleep quality was objecti vely monitored by wrist actigraphy. Sleep efficiency was significantly greater after melatonin than after placebo (83 [SE 4] vs 75 [3]%, p<0 .001) and wake time after sleep onset was significantly shorter (49 [1 4] vs 73 [13] min, p<0.001). Sleep latency decreased, but not signific antly (19 [5] vs 33 [7] min, p=0.088). Total sleep time was not affect ed. The only adverse effects reported were two cases of pruritus, one during melatonin and one during placebo treatment; both resolved spont aneously. Melatonin deficiency may have an important role in the high frequency of insomnia among elderly people. Controlled-release melaton in replacement therapy effectively improves sleep quality in this popu lation.