The endocrinology of the menopausal transition: a cross-sectional study of a population-based sample.

Abstract

In a study of the endocrinology of the perimenopausal years, levels of serum FSH, estradiol (E2), immunoreactive inhibin (INH), testosterone, and sex hormone-binding globulin were measured in a population-based sample of 380 women (mean age, 49.4 yr; range, 45.6-56.9 yr). Subjects were divided into women who reported continuing regular menstrual cycles (27%; group I), a change in menstrual flow without a change in frequency (23%; group II), a change in frequency but no change in flow (9%; group III), changes in both frequency and flow (28%; group IV), and at least 3 months since their last menstrual period (13%; group V). After adjusting for age and body mass index, the geometric mean FSH increased across menstrual groups and, compared with group I, was 53% higher in group IV (P < 0.0005) and 253% higher in group V (P < 0.0001). Age- and body mass index-adjusted geometric means for E2 and INH in group V were 54% and 53% of those in group 1, respectively (P < 0.005, P < 0.0001). Women in group V who did not have a menstrual period in the next year had higher FSH and lower E2 and INH levels than those who subsequently went on to have at least one more menstrual period (P < 0.05). FSH was negatively correlated with E2 (r = -0.30) and INH (r = -0.39), whereas INH was positively correlated with E2 (r = 0.45). We conclude that an increase in serum FSH and decreases in E2 and INH are the major endocrine changes associated cross-sectionally with the menopausal transition.

Impaired fasting glycaemia in middle-aged women: a prospective study

“…The women recruited into our longitudinal study were signi®cantly more likely to exercise at least once per week compared with eligible nonparticipants of the original population-based sample. 9 This may have reduced the incidence of IFG in the current cohort and is a limitation of this study.…”

“…Details of the sample acquisition and characteristics and questionnaire design of the Melbourne Midlife Health Project have been described previously. 8,9 In summary, an initial sample of 2001 Melbourne women who were Australian-born and aged between 45 and 55 y were recruited by random digit telephone dialling in 1991. Women were eligible for the longitudinal study if they had menstruated in the previous 3 months, had an intact uterus and at least one ovary and were not currently taking oral contraceptives or hormone therapy (HT).…”

“…Participants were signi®-cantly more likely than eligible non-participants to: report better health compared with women of the same age; be in paid employment; have had more than 12 y of education; have had a Pap smear; to exercise once a week; and to have undergone dilatation and currettage. 9 Fasting plasma glucose was ®rst estimated in the second year of follow-up in the longitudinal study. The content of this paper represents 6 y of data collection, from the second to the seventh year of follow-up.…”

“…Serum concentrations of FSH, oestradiol (E2), and testosterone (T), were measured as described previously. 9 Sex hormone binding globulin (SHBG) and dehydroepiandrosterone sulphate (DHEAS) were measured by automated enzyme immunoassay using the Immulite system purchased from Diagnostic Products Corporation, California, USA. Free androgen index (FAI) was calculated as the ratio of measured T to measured SHBGÂ100.…”

Symptoms in peri- and postmenopausal women in relation to testosterone concentrations: data from The Women's Health in the Lund Area (WHILA) study

“…A significant amount of T is also loosely bound to albumin, leaving only a small fraction of free circulating T. The effects of estradiol on SHBG levels have been studied during the climacteric period, where higher estrogen levels have been associated with higher SHBG levels 23 . Investigations on when and how much total T, free T and SHBG change due to the menopausal transition have shown different results [23][24][25][26][27][28][29][30][31] . Androstendione (A), which is derived from the adrenal gland and the ovaries, needs to be converted to T to have potent androgenic effects 32 .…”