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.