Plasma androstenedione and oestrone levels in normal and osteoporotic postmenopausal women.

Plasma androstenedione and oestrone concentrations were measured in 72 postmenopasual women. The women included some who had undergone oophorectomy, some with osteoporosis, and normal controls; they were matched for years since menopause. Both hormone concentrations were significantly reduced in the women with osteoporosis. The women who had undergone oophorectomy had hormone concentrations intermediate between the normal and osteoporotic values. Oestrogen deficiency secondary to low androstenedione levels is a major risk factor in postmenopausal osteoporosis, and may be caused by failure of ovarian stromal androgen secretion or some abnormality in the pituitary-adrenal axis.