Effects of melatonin in perimenopausal and menopausal women: a randomized and placebo controlled study

In aging humans, night levels of melatonin (MEL) decline progressively. Als o thyroid and gonadal functions decline during aging while gonadotropins (l uteotropic hormone (LH) and follicle stimulating hormone (FSH)) steadily in crease. A desynchronization of pineal circadian cyclicity as expressed by t he progressive decrease of the MEL night peak may be permissively linked to the onset and progression of menopause. We studied the effects of exogenou s, evening administration of MEL on the level of hormones which are known t o be involved in the genesis and progression of menopause. Perimenopausal and menopausal women from 42 to 62 years of age with no path ology or medication were selected. MEL was measured in saliva to divide the m into low, medium and high-MEL patients. Half of them took 3 mg MEL and ha lf of them Placebo at bedtime (10-12 p.m.) in a fully randomized and double -blind fashion. Three and six months later blood was taken for determinatio n of pituitary (LH, FSH), ovarian, and thyroid hormones I(T-3 and T-4). All women taking MEL with low basal level of MEL and/or Placebo for three and six months showed a significant increase in levels of thyroid hormones. Bef ore initiation of the study, a negative correlation was found in all women between LH, FSH and basal MEL levels. Within six months of treatment, MEL p roduced a significant diminution of LH in the younger women (43 to 49 year- old), while no effect was seen in the older women (50-62 years old). A decr ement of FSH was observed in MEL-treated women with low basal MEL levels. I n addition, most MEL-treated women reported a general improvement of mood a nd a significant mitigation of depression. MEL decline during aging may thu s signal the derangement of pineal and pituitary-controlled ovarian cyclici ty and the progressive quenching of fertility in women. These findings seem to show a recovery of pituitary and thyroid functions in MEL-treated women , towards a more juvenile pattern of regulation. (C) 2001 Elsevier Science Inc. All rights reserved.