Sleep disruption in tetraplegia: a randomised, double-blind, placebo-controlled crossover trial of 3 mg melatonin.

ABSTRACT

STUDY DESIGN: Randomised, double-blind, placebo-controlled crossover trial of melatonin supplementation to people with complete tetraplegia. OBJECTIVES: To investigate the effect that 3 mg melatonin supplementation has on objective and subjective sleep, quality of life and mood of people living with complete tetraplegia. SETTING: Austin Hospital Sleep Laboratory and participants' homes, Melbourne, Victoria, Australia. METHODS: Two week run-in followed by 3 week nightly administration of 3 mg melatonin or placebo, 2-week washout and further 3 week administration of the opposite treatment. Four testing sessions were conducted; the last nights of the run-in, treatment and washout periods. Testing sessions involved recording full polysomnography, completing a questionnaire battery and collecting urine and blood samples. The questionnaires assessed mood, sleep symptoms and health-related quality of life, and the urine and plasma samples assayed 6-sulphatoxymelatonin (aMT6s) and melatonin levels, respectively. A sleep diary was completed throughout the study. RESULTS: Eight participants (mean (s.d.) age 49.5 years (16), postinjury 16.9 years (7.1)) were recruited in which seven concluded the protocol. Endogenous-circulating melatonin was significantly higher (P < or = 0.01) following melatonin (urine 152.94 µg h(-1) (74.51), plasma 43,554.57 pM (33,527.11)) than placebo (urine 0.86 µg h(-1) (0.40), plasma 152.06 pM (190.55)). Subjective sleep improved significantly following melatonin specifically for duration of sleep per night and psychological wellbeing. Objective sleep showed a significant increase in light sleep with melatonin, with all other sleep parameters being unchanged. CONCLUSION: These results suggest that increasing melatonin in people with complete tetraplegia is beneficial, especially for subjective sleep. Investigation of the pharmacokinetics of melatonin metabolism in this population is warranted. SPONSORSHIP This project is proudly supported by the Transport Accident Commission.