Dose-response evaluation of cyclic estrogen/gestagen in postmenopausal women: placebo-controlled trial of its gynecologic and metabolic actions.

In order to study dose-response relationships of estrogen in normal postmenopausal women, 100 volunteers were randomized to 12 months' treatment with placebo or one of three different doses (high, medium, or low) of natural estrogens (17 beta-estradiol and estriol), sequentially combined with norethisterone acetate for 10 of the 28 cycle days. A total of 87 women completed the trial with examinations every 3 months. Relief of climacteric symptoms was dose related, being 70%, 56%, and 33% in the high, medium, and low estrogen groups and unchanged in the placebo group. Regular vaginal bleeding occurred in 78% receiving high-dose in 64% receiving medium-dose, and in 40% receiving low-dose estrogen. Bone mass increased in the high and medium groups, was unchanged in the low group, and declined in the placebo group. Dose-related decreases in serum cholesterol of 10%, 5%, and 3% occurred in the three respective estrogen groups. Serum triglyceride levels, blood pressure, and body weight remained unchanged in all groups.