A LONGITUDINAL-STUDY OF THE PERIMENOPAUSAL TRANSITION - ALTERED PROFILES OF STEROID AND PITUITARY-HORMONES, SHBG AND BONE-MINERAL DENSITY

From a longitudinal prospective study, 160 women with spontaneous meno pause and without steroid medication were followed during the transiti on from pre- to postmenopause. After 12 years 152 women were still par ticipating in the study, Blood samples were drawn every 6 months until 1 year after the menopause and every 12 months thereafter, Measuremen ts of bone mineral density (BMD) on the forearm were performed every s econd year. All women routinely completed a questionnaire concerning s ymptoms frequently attributed to the climacteric period. All data were grouped around the onset of the menopause, thereby allowing longitudi nal evaluation of the changes in the variables from the premenopausal to the postmenopausal period. The beginning of the perimenopausal peri od was characterized by transitory elevations of follicle-stimulating hormone (FSH). A significant increase in serum levels of gonadotropins was observed for both FSH and luteinizing hormone (LH) from about 5 y ears before the menopause. Within the 6 month period around the menopa use there was a further increase which culminated within the first pos tmenopausal year for LH and 2-3 years postmenopause for FSH. Thereafte r, a continuous decrease in LH occurred over the following 8 years, Wi th respect to FSH, there was a slight decline starting about 4 years p ostmenopause. During the premenopausal period an increasing frequency of inadequate luteal function or anovulation occurred and, in the post menopausal years, the serum levels of progesterone (P) were invariably low. Gradually, the ratio between estrone (E(1)) and 17-beta-estradio l (E(2)) increased, reflecting the declining follicular steroidogenesi s. A marked decrease in estrogen levels occurred during the 6 month pe riod around the menopause, most pronounced in E(2). During the next 3 years, the levels of E(2) and E(1) showed an essentially parallel, mod erate decline. Around the menopause, serum levels of testosterone (T), Delta(4)-androstenedione (A) and sex hormone-binding globulin (SHBG) showed small but significant decreases. From about 3 years postmenopau se, the levels were relatively constant over the following 5 years. A decrease in BMD was observed in the postmenopause, and from about 3 ye ars postmenopause, estradiol correlated positively with BMD, Before, a s well as after the menopause, body mass index (BMI) showed an inverse correlation with SHBG.