Long-term effects of percutaneous estradiol on bone loss and bone metabolism in postmenopausal hysterectomized women

Objective: To determine whether percutaneous estradiol (pE 2) (1.5 mg/day) is able to counteract the postmenopausal bone loss in postmenopausal hysterectomized women, in a double-blind study versus oral estriol (E 3) (2 mg/day). Methods: The bone mineral density of the lumbar spine (LS) and of the proximal femur (PF) was measured every 3 months by dual energy X-ray absorptiometry for 2 years in 43 hysterectomized postmenopausal women (21 in the E 2 group and 22 in the E 3 control group), and in a subset of patients for a 3rd year. The statistical analyses were performed on Macintosh using StatView II TM. Results: A significant bone loss of 1.2 (0.4)% and of 1.3 (0.3)% per year was observed in the control group, respectively at LS and at PF, versus a significant gain of 1.2 (0.5)% per year in the treated group at the LS. No significant change at PF occurred in the treated group. In the 20 patients followed up for a 3rd year on pE 2, an increase of 1.2 (0.9) and 2.5 (1.4)% at LS in the 12 former active group patients and the eight formerly control patients, respectively was seen. The same trend was observed at the proximal femur. Conclusion: pE 2 (1.5 mg E 2) is able to counteract the postmenopausal bone loss in hysterectomized women, whereas E 3 (2 mg/day administered orally) is unable to maintain bone mass.