Treatment of Postmenopausal Osteoporosis with Transdermal Estrogen

TLDR

The study evaluated the tolerance and effectiveness of transdermal estrogen in postmenopausal women with osteoporosis and vertebral fractures. In a 1‑year, double‑blind, randomized, placebo‑controlled trial, 75 postmenopausal women with vertebral fractures received 0.1 mg/day transdermal estradiol plus oral medroxyprogesterone, while bone turnover, density, and fracture rates were monitored via biochemical markers, histomorphometry, and serial DXA. Transdermal estradiol increased lumbar spine, femoral trochanter, and midradius bone mineral density, reduced bone turnover markers and formation rates, and lowered vertebral fracture incidence (relative risk 0.39) compared with placebo.

Abstract

To evaluate the tolerance and effectiveness of transdermal estrogen for women with established postmenopausal osteoporosis and vertebral fractures.Double-blind, randomized, placebo-controlled clinical trial lasting 1 year.Referral-based outpatient clinic.Seventy-five postmenopausal women, 47 to 75 years of age, with one or more vertebral fractures due to osteoporosis.Thirty-nine women received dermal patches delivering 0.1 mg of 17 beta-estradiol for days 1 to 21 and oral medroxyprogesterone acetate for days 11 to 21 of a 28-day cycle. Another 39 women received placebo.Bone turnover assessed by biochemical markers and iliac bone histomorphometry; bone loss assessed by serial measurement of bone density; and vertebral fracture rate.Compared with the placebo group, the median annual percentage change in bone mineral density in the estrogen group reflected increased or steady-state bone mineral density at the lumbar spine (5.3 compared with 0.2; P = 0.007), femoral trochanter (7.6 compared with 2.1; P = 0.03), and midradius (1.0 compared with -2.6, P less than 0.001) but showed no significant difference at the femoral neck (2.6 compared with 1.4; P = 0.17). Estrogen treatment uniformly decreased bone turnover as assessed by several methods including serum osteocalcin concentration (median change, -0.35 compared with 0.02 nmol/L; P less than 0.001). Histomorphometric evaluation of iliac biopsy samples confirmed the effect of estrogen on bone formation rate per bone volume (median change, -12.9 compared with -6.2% per year; P = 0.004). Also, 8 new fractures occurred in 7 women in the estrogen group, whereas 20 occurred in 12 women in the placebo group, yielding a lower vertebral fracture rate in the estrogen group (relative risk, 0.39; 95% CI, 0.16 to 0.95).Transdermal estradiol treatment is effective in postmenopausal women with established osteoporosis.