Changes in nocturnal melatonin secretion in perimenopausal women: correlation with endogenous estrogen concentrations.
Level 3 - non-randomized controlled study
Non-randomized prospective cohort study with before-after interventional comparisons
PubMed 10709973 · doi:10.1034/j.1600-079x.2001.280207.x
What was done
Researchers measured nocturnal serum melatonin every 2 hours across three groups: 46 premenopausal women, 44 postmenopausal women, and 11 premenopausal women with uterine leiomyoma undergoing hysterectomy and bilateral salpingo-oophorectomy. They evaluated the correlation between peak nocturnal melatonin and serum 17 beta-estradiol, assessed the effect of oral conjugated estrogen (0.625 mg daily) in postmenopausal women, and measured melatonin changes following surgical oophorectomy.
What was found
In premenopausal women, nocturnal melatonin declined moderately from age 17 to 45 but increased between ages 46 and 50. Postmenopausal women showed a steep decline in melatonin secretion for up to 15 years post-menopause, followed by a gradual decline. In premenopausal women aged 40–50, peak nocturnal melatonin was negatively correlated with serum 17 beta-estradiol (r = -0.661, P < 0.0005). Conjugated estrogen administration in postmenopausal women suppressed nocturnal melatonin secretion (P < 0.005), whereas acute estrogen loss from oophorectomy significantly increased nocturnal melatonin (P < 0.0001).
Why it matters
These findings suggest that the transient rise in melatonin during perimenopause is driven by dropping estrogen levels rather than age alone, providing insight into neuroendocrine alterations during the menopausal transition.
Limits
The abstract does not specify the exact sample size or protocol duration for the postmenopausal estrogen intervention subgroup. The study is non-randomized, and potential confounders such as sleep patterns, light exposure, and circadian disruptions were not reported in the abstract.
Cited by
- context Endogenous melatonin production in the human body begins to decline around age 50.