Hormonal treatments modulate pulsatile plasma growth hormone, gonadotrophin and osteocalcin levels in postmenopausal women

Oestrogen plays a role in modulating growth hormone (GH), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and osteocalcin secretion in women. Indeed, the postmenopausal period is characterized by changes in plasma GH, LH, FSH and osteocalcin levels. The aim of the present study was to investigate the changes in the secretory patterns of these hormones in postmenopausal women under different therapeutic regimens. A total of 20 subjects took part in the study. They were subdivided into four groups comprising 5 untreated postmenopausal women (time since menopause 1-5 years), 5 postmenopausal women receiving steroid hormone replacement therapy, 5 postmenopausal women receiving salmon calcitonin and 5 fertile women with regular menstrual cycles. Blood samples were collected every 15 min for 4 h and hormone levels were measured by radioimmunoassay. Plasma GH levels fell in the postmenopausal women, but were restored under oestrogen-progestogen treatment. The pulsatile patterns of plasma LH and FSH did not show significant differences in the treated and untreated women. Plasma osteocalcin levels showed episodic fluctuations and mean levels decreased under steroid hormone or calcitonin treatment. No significant correlation was observed between plasma GH and osteocalcin or gonadotrophin levels or body mass index.