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

Insomnia is a condition characterized by difficulty in initiating or maintaining sleep or by chronic nonrestorative and poor-quality sleep, despite adequate opportunities and conditions for sleep. The prevalence of insomnia increases with age and in particular results in poor subjective sleep quality. Approximately 50% of older adults complain of insomnia and are generally dissatisfied with the quality of their sleep. A survey conducted as part of the National Institute on Aging Established Populations for Epidemiologic Studies of the Elderly (EPESE) found that 42% of community-dwelling elderly people reported difficulties in falling and staying asleep, but more than two-thirds of insomnia cases are undiagnosed, and physicians are seldom trained to detect or enquire about symptoms of insomnia. Although the total amount and type of sleep varies throughout the life cycle, and the prevalence of insomnia is higher in older adults, insomnia is not necessarily an inevitable consequence of aging. Insomnia is particularly challenging for clinicians because of the lack of treatment guidelines, especiallyregarding the elderly population, and because of different methods used in clinical trials. Poor sleep is correlated with morbidity and mortality in older adults. In addition to daytime dysfunction, insomnia is associated with various adverse effects such as poorer quality of life in institutionalized individuals and public health concerns that are related, but not limited, to the associated direct and indirect costs. For example, epidemiological studies have indicated that people with sleep disturbance are much more likely to require health care, which imposes a substantial economic burden on individuals and healthcare systems. Moreover, accumulating evidence suggests that sleep problems are related to slips and falls in older adults. Insomnia also impairs normal daytime functioning as a result of sleep insufficiency. These impairments generally include fatigue, irritability, poorer memory and concentration, and malaise. A greater incidence of depressive symptoms correlates with poor sleep quality or chronic insomnia, disturbances that appear to be major risk factors for depression. Hence, an understanding of the physiological mechanisms of sleep regulation, and especially of the consequences of their breakdown, can help to unravel the complexities of the pathophysiology of depressive disorders. Melatonin plays an important role in this context. Disturbances in the rhythm and amplitude of melatonin secretion may account for symptomatic disturbances to sleep and mood. Moreover, the close association between sleep and mood disorders suggests that melatonin may be important in mood management. Melatonin treatment not only improved total sleep time, but also reduced depressive symptoms, indicating a relationship between sleep disturbance and symptoms of depression.
The pineal hormone melatonin (N-acetyl-5-methoxytryptamine) acts as a neuroendocrine transducer of the light–dark cycle. It plays an important role in regulating human circadian rhythms and may have sleep-inducing effects in humans.18,19 Melatonin production declines with age and is lower in middle-aged and elderly adults with insomnia than in good sleepers. Long-term use of sedative-hypnotics for insomnia lacks an evidence base and has traditionally been discouraged for reasons that include concerns about potential adverse drug effects, such as cognitive impairment (anterograde amnesia), daytime sedation, motor incoordination, and risk of motor vehicle accidents and slips and falls. In addition, the effectiveness and safety of long-term use of these agents remain to be determined. Moreover, several studies have been conducted to assess the effects of sleep hygiene interventions and various nonpharmacological interventions, such as physical activity, bright light exposure, and noise abatement, but no definite effect on night time sleep has been reported. Many people seek treatment for insomnia using alternative and complementary medicine. Generally, the main goal of nonpharmacological remedies in the treatment of primary insomnia is to correct behavior patterns that are not conducive to a good quality sleep, and nutrients might play a significant role in this setting, but no evidence is available as to the preferred alternative treatment of insomnia, and in particular, controlled clinical trials are lacking in this field. In addition to melatonin, other micronutrients such as zinc and magnesium may play a role in facilitating sleep. Zinc exhibits an antidepressant-like activity, as stated in a preclinical model of depression and in two other clinical trials.25,26 Significant clinical correlates were shown related to its action as an antagonist of the glutamate/N-methyl-D-aspartate receptor. Magnesium has beneficial effects on mood and is crucial, together with zinc, in the endogenous synthesis of melatonin. The purpose of this double-blind, placebo-controlled clinical trial was to assess the efficacy and safety of the combination of melatonin (5 mg), magnesium (225 mg), and zinc (11.25 mg), conveyed in pear pulp (100 g), in improving quality of sleep and morning alertness in adults aged 70 and older who met the criteria for primary insomnia.

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

INTERVENTION: Participants took a food supplement (5 mg melatonin, 225 mg magnesium, and 11.25mg 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 score56.8; 95% confidence interval55.4–8.3, Po.001). Moreover, the significant improvements in all four domains of the LSEQ (ease of getting to sleep, Po.001; quality of sleep, Po.001;hangover on awakening from sleep, P5.005; alertness and behavioral integrity the following morning, P5.001), in SDQ score (Po.001), in total sleep time (Po.001), and in SF-36 physical score (P5.006) 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.

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