Melatonin, aging effects

In contrast, another meta-analysis undertaken by Brzezinski et al., using 17 different studies involving 284 subjects, most of whom were older, concluded that melatonin is effective in increasing sleep efficiency and reducing sleep onset time (Brzezinski et al. 2005). Based on this meta-analysis the use of melatonin in the treatment of insomnia, particularly in aged individuals with nocturnal melatonin deficiency, was proposed. 

Garfinkel et al. (168) conducted an investigation of melatonin s effects on sleep quality in 12 elderly subjects with insomnia [seven men, five women mean age, 76 years (range, 68 to 93 years standard deviation (SD), 8 years)]. These authors used a randomized, double-blind, crossover design with 2 mg controlled-release melatonin or a placebo taken 2 hours before desired bedtime every night for 3 weeks. After a 1-week washout, the subjects then received 3 weeks treatment with the other preparation. Compared with placebo, the controlled-release melatonin improved the sleep quality of these elderly subjects and was well tolerated. Further, 2 months treatment with 2 mg of controlled-release melatonin in these relatively healthy elderly subjects was much more effective than 1 week of treatment ( 168). 

Researchers still have not investigated melatonin s effectiveness in treating insomnia in most age groups. As of 2000, only three studies had investigated the usefulness of melatonin in treating insomnia in people younger than 65 years of age. 

Melatonin production decreases with advancing age, and in a small number of insomniacs, true melatonin deficiency occurs. Whether melatonin is effective for those who are not melatonin-deficient is not known, and research does not support the indiscriminate use of this supplement. 

Skene DJ, Swaab DF (2003) Melatonin rhythmicity effect of age and Alzheimer s disease. Exp Gerontol 38 199-206... 

A reduced endogenous melatonin production seems to be a prerequisite for effective exogenous melatonin treatment of sleep disorders. A recent metaanalysis of the effects of melatonin in sleep disturbances, including all age... 

The natural production of melatonin by the pineal gland peaks at the age of only four or five years of age. Since a decrease in its production occurs during sexual maturation, researchers warn that taking it during adolescence may have a detrimental effect on puberty. 

Low bone density is also associated with oxidative stress in lower species. Thus, in ovariectomized rats melatonin has a bone-protective effect, which depends in part on its free radical-scavenging properties (Cardinali et al., 2003). A mouse model that has been used to study the role of ROS in age-related disorders including osteoporosis is the accelerated mouse-senescence-prone P/2 (SAM-P/2) that generates increased oxygen radicals (Hosokawa, 2002 Udagawa, 2002). This model could be very useful in studying the role of lycopene in osteoporosis. 

Greenblatt DJ, Harmatz JS, Karim A. Age and gender effects on the pharmacokinetics and pharmacodynamics of ramelteon, a hypnotic agent acting via melatonin receptors MTi and MT2. J Clin Pharmacol 2007 47 485 -96. 

So the doctors at a clinic in Modena decided to evaluate the effect of melatonin on the daily blood pressure variance in nine women with normal blood pressure and another nine whose hypertension was being treated with ACE inhibitor drugs. Their ages ranged from forty-seven to sixty-three. For three weeks, the women... 

Few clinical trials have been done in insomnias that are not associated with circadian rhythm disorders. Large doses of melatonin may have a therapeutic effect in chronic insomnia. Insomnia that coincides with diminished melatonin secretion occurs in aging and following treatment with beta-adrenoceptor blockers. Trials of melatonin treatment for... 

Nervous system In a comparison of the effects of single doses of melatonin 2-6 mg and chloral hydrate on sleep electroencephalography in a randomized study of 348 children aged 1 month to 6 years, melatonin was well tolerated and associated with less drowsiness than chloral hydrate [48 ]. Two of those who took melatonin developed diarrhea and two developed agitation, but there was insufficient information to assess causality. 

Randomised trials A randomised, placebo-controlled trial of controlled-release melatonin (3 mg) for treating insomnia in children (N = 160, mean age = 6.6 years, 82% male) reported that the melatonin treatment was well tolerated with no adverse effects reported or observed and normal blood and urine analyses recorded across treatment groups [52 ]. 

A randomised, placebo-controlled trial examining 3 weeks of melatonin treatment (2.5 mg) for the treatment of sleep disturbances in 16 hypertensive patients (aged 45-64 years 56% female) treated with beta-blockers found that melatonin treatment was effective at improving sleep quality with no adverse side effects, tolerance or rebound insomnia observed [57=]. 

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