Relation of demographic factors, menstrual history, reproduction and medication use to sex hormone levels in postmenopausal women

In postmenopausal women, levels of estrogens, androgens, and perhaps prolactin have been related to risk of breast and other hormonal cancers in women. However, the determinants of these hormone concentrations have not been firmly established. Associations among various demographic, menstrual, and reproductive factors, medication use and endogenous sex hormone concentrations (estradiol, free estradiol, estrone, estrone sulfate, testosterone, free testosterone, sex hormone binding globulin, androstenedione, dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), dihydrotestosterone, and prolactin) were evaluated in a cross-sectional analysis from a simple random sample of 274 postmenopausal women selected from the Women's Health Initiative Dietary Modification Trial. In multiple regression analyses on log-transformed hormones, the concentrations of DHEA, and DHEAS were negatively and statistically significantly associated with age (both β = -0.03, P < 0.001, respectively). Estradiol, estrone, DHEA, and free testosterone concentrations were higher in African-American than in non-Hispanic White women, but after multivariate adjustment the associations were statistically significant only for free testosterone (β = 0.38, P = 0.01). Women who had a history of bilateral oophorectomy had a mean 35% lower testosterone concentration compared with women with at least one ovary remaining (β = -0.43, P = 0.002), and lower free testosterone (β = -0.42, P = 0.04) after multivariate adjustment. Women who reported regular use of NSAIDs had higher DHEA concentrations (β = 0.20, P = 0.04) and lower prolactin concentrations (β = -0.18, P = 0.02) compared with non-users. These results suggest that while age, oophorectomy status, and NSAID use may be associated with selected sex hormone concentrations, few menstrual or reproductive factors affect endogenous sex hormones in the postmenopausal period.