Melatonin Treatment for Age-Related Insomnia

Abstract

Older people typically exhibit poor sleep efficiency and reduced nocturnal plasma melatonin levels. The daytime administration of oral melatonin to younger people, in doses that raise their plasma melatonin levels to the nocturnal range, can accelerate sleep onset. We examined the ability of similar, physiological doses to restore nighttime melatonin levels and sleep efficiency in insomniac subjects over 50 yr old. In a double-blind, placebo-controlled study, subjects who slept normally (n = 15) or exhibited actigraphically confirmed decreases in sleep efficiency (n = 15) received, in randomized order, a placebo and three melatonin doses (0.1, 0.3, and 3.0 mg) orally 30 min before bedtime for a week. Treatments were separated by 1-wk washout periods. Sleep data were obtained by polysomnography on the last three nights of each treatment period. The physiologic melatonin dose (0.3 mg) restored sleep efficiency (P < 0.0001), acting principally in the midthird of the night; it also elevated plasma melatonin levels (P < 0.0008) to normal. The pharmacologic dose (3.0 mg), like the lowest dose (0.1 mg), also improved sleep; however, it induced hypothermia and caused plasma melatonin to remain elevated into the daylight hours. Although control subjects, like insomniacs, had low melatonin levels, their sleep was unaffected by any melatonin dose.

Tryptophan-enriched cereal intake improves nocturnal sleep, melatonin, serotonin, and total antioxidant capacity levels and mood in elderly humans

“…About 30 % of people over 50 years suffer from sleep problems (Zhdanova et al 2001). This is partially attributed to age-related shorter amplitude and advance in phase of circadian rhythms (Van Someren 2000;Dijk et al 2000).…”

“…Many hormones and neurotransmitters are involved in sleep regulation (Sánchez et al 2010;Kotronoulas et al 2009) being of importance the indole melatonin and the neurotransmitter serotonin (Hajak et al 1991;Silber and Schmitt 2009). Since both serotonin and melatonin circulating levels decrease with increasing age, the occurrence of sleep problems in the elderly may be a consequence of the age-related impairment in the synthesis and secretion of both the neurotransmitter and the indole (Zhdanova et al 2001).…”

Evidence for the efficacy of melatonin in the treatment of primary adult sleep disorders

“…Quantitative analysis of the five eligible RCTs [44,[46][47][48][49] showed an overall significant reduction in the time to fall asleep between the effect on sleep onset latency for melatonin in patients with primary insomnia compared with placebo (Total mean difference = -5.05 minutes, 95% CI: -8.51, -1.59). The overall estimated score of melatonin treatment was significant (Z=2.86, P=0.004) (Fig.2).…”

“…In all five studies for primary insomnia [44][45][46][47][48][49] there were large sample sizes, which increased reliability of results (n=40-791). The studies used a thorough prescreening assessment which was deployed to reduce confounding factors and use of medications such as benzodiazepines were stopped beforehand.…”

“…Participants unsuitable (n= 5) [26][27][28][29][30] Insufficient data for analysis (n= 2) [31,32] Inappropriate method and data collection (n= 4) [33][34][35][36] No clear comparison group (n= 4) [37][38][39][40] Number of studies included in review (n=13) [41][42][43][44][45][46][47][48][49][50][51][52] Publications handpicked (screening reference list) (n= 2) …”