The Effect of Melatonin, Magnesium, and Zinc on Primary Insomnia in Long-Term Care Facility Residents in Italy: A Double-Blind, Placebo-Controlled Clinical Trial

OBJECTIVES: To determine whether nightly administration of melatonin, magnesium, and zinc improves primary insomnia in long-term care facility residents. DESIGN: Double-blind, placebo-controlled clinical trial. SETTING: One long-term care facility in Pavia, Italy. PARTICIPANTS: Forty-three participants with primary insomnia (22 in the supplemented group, 21 in the placebo group) aged 78.3±3.9. INTERVENTION: Participants took a food supplement (5 mg melatonin, 225 mg magnesium, and 11.25 mg zinc, mixed with 100 g of pear pulp) or placebo (100 g pear pulp) every day for 8 weeks, 1 hour before bedtime. MEASUREMENTS: The primary goal was to evaluate sleep quality using the Pittsburgh Sleep Quality Index. The Epworth Sleepiness Scale, the Leeds Sleep Evaluation Questionnaire (LSEQ), the Short Insomnia Questionnaire (SDQ), and a validated quality-of-life instrument (Medical Outcomes Study 36-item Short Form Survey (SF-36)) were administered as secondary end points. Total sleep time was evaluated using a wearable armband-shaped sensor. All measures were performed at baseline and after 60 days. RESULTS: The food supplement resulted in considerably better overall PSQI scores than placebo (difference between groups in change from baseline PSQI score=6.8; 95% confidence interval=5.4–8.3, P<.001). Moreover, the significant improvements in all four domains of the LSEQ (ease of getting to sleep, P<.001; quality of sleep, P<.001; hangover on awakening from sleep, P=.005; alertness and behavioral integrity the following morning, P=.001), in SDQ score (P<.001), in total sleep time (P<.001), and in SF-36 physical score (P=.006) suggest that treatment had a beneficial effect on the restorative value of sleep. CONCLUSION: The administration of nightly melatonin, magnesium, and zinc appears to improve the quality of sleep and the quality of life in long-term care facility residents with primary insomnia.