Very-low-dose estradiol increases BMD

An estradiol dose of 14 µg reduces bone turnover and preserves bone mineral density (BMD) in postmenopausal women, say results of a randomized trial presented at the 15th Annual Meeting of the North American Menopause Society. The once-a-week regimen also does not stimulate the endometrium or increase vaginal bleeding.

Nine clinical centers participated in the double-blind, placebo-controlled study, which randomized more than 400 women to 14 µg of estradiol or placebo, plus calcium (400 mg) and vitamin D (400 IU), daily. The participants were 60 to 80 years old, at least 5 years postmenopausal, and all had intact uteruses and normal BMD.

Over the study period, total hip BMD increased 0.4% in the treatment group and declined 0.8% in the placebo group (P<0.001). Comparison of endometrial biopsies done at baseline and 2 years showed that fewer than 2% of those taking estradiol had any proliferation. The difference in the 2-year hyperplasia rate for treatment versus placebo was 0.5% (95% CI: 0-7.3). The most common side effect was vaginal secretions, reported by 22 of the women on estradiol compared with three of those on placebo (P<0.05).