The prevalence of POF appears to vary by ethnicity. Health factors associated with POF also vary by ethnicity but because of the cross-sectional study design, it is not possible to determine cause and effect relationships. Health risks of POF would benefit from further study.

We measured serum reproductive hormone concentrations in a community-based, multiethnic population of premenopausal and early perimenopausal women to determine whether there are ethnic differences in hormones that can be explained by host factors. We studied 2930 participants in the Study of Women's Health Across the Nation who were aged 42-52 yr and self-identified as African-American (27.6%), Caucasian (47.1%), Chinese (7.4%), Hispanic (8.8%), or Japanese (9.0%) at 7 clinical sites. Outcome measures from this baseline assessment of a longitudinal study were serum estradiol (E2), FSH, testosterone (T), dehydroepiandrosterone sulfate, and SHBG concentrations and calculated estimates of free steroid availability, free testosterone index, and free E2 index from serum collected primarily in the early follicular phase of a spontaneous menstrual cycle. The primary explanatory variables were race/ethnicity, menopausal status, age, body mass index, day of the cycle, smoking, alcohol use, and physical activity. Chinese women had lower unadjusted E2 and SHBG levels, and Hispanic women had lower unadjusted T levels than other ethnic groups. Unadjusted serum FSH levels did not differ by race/ethnicity. E2 levels adjusted for host characteristics, particularly body size, did not differ by race/ethnicity. Adjusted FSH levels were higher, and adjusted T levels were lower in African-American and Hispanic women. Serum E2 and FSH concentrations were highly variable. Serum FSH levels, but no other hormone concentrations, were positively correlated with menopausal status. Serum dehydroepiandrosterone sulfate levels were negatively correlated with age, but not menopausal status. All hormone concentrations were significantly correlated with body mass index. We conclude that serum sex steroid, FSH, and SHBG levels vary by ethnicity, but are highly confounded by ethnic disparities in body size. to reproductive senescence in women is characterized by a progressive loss of ovarian response to pituitary stimulation as ovarian follicles lose the ability to develop, mature, and ovulate reproductively competent oocytes. Endocrinologically, this process of reproductive aging is characterized by a progressive rise in serum FSH levels associated with a decrease in serum estradiol (E2) levels (1), although current evidence suggests stage-specific variation in this general pattern (2). In contrast, serum dehydroepiandrosterone sulfate (DHEAS) levels decrease steadily with age without any known relationship to the loss of ovarian folliculogenesis (3, 4), leading to consideration of DHEAS as a marker of somatic aging. Once again, evidence is emerging that menopause stage-specific data are at variance with that pattern (5).No study, whether cross-sectional (6) or longitudinal (1,7,8), has investigated ethnic differences in reproductive hormones in midlife women. However, ethnic variation in hormone concentrations has been observed in menopausal women, as serum E2 levels are lower in Chinese women than in Caucasian women (9). In addition, host facto...

The possible presence of gonadotropin receptors in nonpregnant human uterus and human fetoplacental unit was investigated by light microscope immunocytochemistry using a monoclonal antibody to rat luteal hCG/LH receptors. The receptor antibody cross-reacted with human and bovine hCG/LH receptors and appears to be directed against the receptor rather than other proteins, including HLA class I antigens. Uterus and fetoplacental unit contained receptor antibody-binding sites, which indicates the presence of hCG/LH receptors. In the endometrium these receptors were present in glandular and luminal epithelial cells as well as in stromal cells. In the myometrium the receptors were detected in circular and elongated myometrial smooth muscle and vascular smooth muscle. Comparison of immunostaining intensities, which indicates the presence of different amounts of receptors, revealed that luminal and glandular epithelial cells contained more receptors than stromal cells. These cells, in turn, contained more receptors than myometrial and vascular smooth muscle. All cells in secretory phase uterine specimens contained more receptors than corresponding cells from the proliferative phase of the cycle. Midpregnancy placenta, amniotic epithelium, chorionic cytotrophoblasts, and decidual cells contained hCG/LH receptors. At term pregnancy, while receptors in fetal membranes and decidua continue to be detected, placental tissues did not show any detectable receptors unless the tissues were pretreated with neuraminidase. This indicated that term pregnancy placenta contain hCG/LH receptors masked by sialic acid residues. Comparison of immunostaining intensities suggested that syncytiotrophoblasts contained more receptors than cytotrophoblasts at midpregnancy; mesenchymal cells or blood vessels contained no detectable receptors. There were more receptors in decidua than in fetal membranes at mid- and term pregnancy. While the amniotic epithelial receptors decreased, the receptors in chorionic cytotrophoblasts and decidual cells increased from mid- to term pregnancy. In summary, hCG/LH receptors were demonstrated in the nonpregnant human uterus, human placenta, fetal membranes, and decidua. This indicates that hCG/LH may directly regulate functions of these tissues by endocrine, autocrine, or paracrine mechanisms.

Serum reproductive hormone concentrations were measured longitudinally in a community-based, multiethnic population of midlife women to assess whether ethnic differences exist in the patterns of change in estradiol (E2) and FSH and, if so, whether these differences are explained by host characteristics. We studied 3257 participants from seven clinical sites in the Study of Women's Health Across the Nation (SWAN) who were aged 42-52 yr at baseline and self-identified as African American (28.2%), Caucasian (47.1%), Chinese (7.7%), Hispanic (8.4%), or Japanese (8.6%). E2 and FSH were assayed in serum collected primarily in the early follicular phase of a spontaneous menstrual cycle in three consecutive annual visits. The primary explanatory variables included in repeated-measures regression analyses were race/ethnicity, menopausal status, age, body mass index (BMI), day of the cycle, smoking, parity, socioeconomic status, study site, and the self-report of diabetes at baseline. At the baseline visit, 46.2% of the women were classified as being early perimenopausal, with the remaining being premenopausal. By the second follow-up visit, 5.5% of the women in that cohort were postmenopausal, 66.8% were early perimenopausal, 8.3% were late perimenopausal, and 19.4% remained premenopausal. Serum E2 concentrations decreased significantly with age, with a steeper decline at higher ages. FSH concentrations increased significantly with age, with a steeper increase at higher ages. Similar patterns in the decline of E2 and the increase in FSH with age were found across ethnic groups, but the levels of these hormones differed by race/ethnicity. Specifically, over time, Chinese and Japanese women had lower E2 concentrations but similar FSH levels, compared with Caucasian women, and African American women had higher FSH concentrations but comparable E2 levels with those of Caucasian women. These ethnic differences in E2 and FSH were independent of menopausal status. The effect of BMI on serum E2 and FSH levels varied by menopausal status. Increasing BMI was associated with decreasing concentrations of E2 among premenopausal and early perimenopausal women but was associated with increasing concentrations of E2 among late perimenopausal and postmenopausal women. Increasing BMI was associated with decreasing concentrations of FSH, with the effect of BMI becoming larger as women transitioned through menopause. We conclude that serum E2 levels decrease and FSH concentrations increase with increasing age in midlife women, that ethnic differences in E2 over time differ from ethnic differences in FSH and suggest ethnic differences in the pituitary-ovarian relationship, and that the effect of BMI on E2 and FSH concentrations varies by menopausal status.

The dynamics of reproductive hormones that characterize the menopausal transition (perimenopause) are incompletely understood, particularly in non-Caucasian women. The Study of Women's Health across the Nation (SWAN) is a multiethnic cohort study of 3302 women at seven sites who were aged 42-52 yr at baseline. All participants are seen annually to assess a variety of endpoints. A subcohort of 848 women undergoes further investigation of their daily patterns of reproductive hormones in the Daily Hormone Study (DHS). DHS enrollees annually complete a daily collection of first morning voided urine for an entire menstrual cycle or up to 50 d (whichever comes first). Chemiluminescent assays measured urinary LH and FSH, as well as metabolites of estradiol [estrone conjugates (E1c)] and progesterone [pregnanediol glucuronide (Pdg)]. Cycles were assessed for evidence of luteal activity and day of luteal transition using previously developed algorithms. Midreproductive-aged women who underwent similar daily urinary analyses served as historical controls. Correlates of cycle features were identified. Eight hundred thirty-three cycles were evaluable and had complete data on covariates. Six hundred seventy-four (80.9%) cycles had evidence of luteal activity, and 159 (19.1%) did not. Women who were at least 49 yr old were less likely to have cycles with luteal activity and had more variable cycle length, higher total-cycle FSH, and lower total-cycle Pdg. Compared with heavier women, those with body mass index less than 25 kg/m2 had shorter cycles and higher total-cycle LH, FSH, and Pdg but not E1c. Chinese- and Japanese-American women had overall lower adjusted total-cycle E1c excretion. Smoking was not significantly associated with cycle length or hormones. When compared with cycles of younger control women, the cycles of the SWAN DHS participants had higher gonadotropins, lower total integrated Pdg, and E1c levels that were not different, which suggests that the ovary retains sensitivity to elevated FSH in the early menopausal transition. In this cross-sectional study of women over age 42 who are premenopausal or in the early menopausal transition, there were important differences in the characteristics of cycles related to age, body mass index, and ethnicity. Comparisons to younger women indirectly support the inhibin hypothesis, which proposes that the initiating event in the menopausal transition is the loss of inhibin negative feedback on FSH secondary to a diminished follicular reserve.