The endocrinology of the menopause.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic search methodology or primary experimental data
PubMed 10418978 · doi:10.1016/s0960-0760(98)00145-9
What was done
This narrative review synthesizes endocrine dynamics during the menopausal transition and early postmenopause, focusing on changes in ovarian primordial follicle count and circulating concentrations of dimeric inhibins (inhibin A and inhibin B), follicle-stimulating hormone (FSH), estradiol, and androgens.
What was found
Primordial follicle numbers decrease with age up to roughly age 38, after which the decline accelerates during the final ~12 years of reproductive life. Regularly cycling women over 40 with elevated FSH exhibit significantly lower early follicular-phase inhibin B levels. The initial endocrine event of early cycle irregularity is falling inhibin B. In late perimenopause, estradiol and inhibin A drop while inhibin B stays low and FSH rises markedly. Circulating androgens decline with chronological age rather than demonstrating a direct link to menopausal stages. The abstract reports no numerical hormone concentrations or exact effect sizes.
Why it matters
It maps the endocrine sequence underlying ovarian aging and explains why substantial hormonal fluctuations make isolated FSH and estradiol measurements unreliable indicators of menopausal status.
Limits
As a narrative review, the abstract provides no specific sample size, search methodology, or primary quantitative data. It does not report precise numerical ranges or confidence intervals for the referenced hormones.
Cited by
- context During perimenopause, progesterone is the first hormone to decline.