Moderation of the daily dose of HRT: prevention of osteoporosis

Abstract

Introduction and methods: Osteoporosis is the most common bone disease in clinical practice. Between 30% and 50% of postmenopausal women and almost 50% of all people over the age of 75 are estimated to have osteoporosis. HRT is well known for reducing the risk of osteoporosis in postmenopausal women but compliance with long-term HRT therapy remains low. The use of low dose HRT reduces the estrogenic adverse events which often cause patients to stop therapy. In this paper, the current literature on the benefits of low dose HRT and osteoporosis prevention are reviewed. Results: Various studies have assessed the efficacy of low-dose HRT (25 mcg/day transdermally; 0.3 mg/day orally) in the prevention of osteoporosis. Low dose HRT is effective at reducing bone loss in postmenopausal and oophorectomised women. In one study of 218 postmenopausal women, a dose of 0.3 mg/day of esterified estrogen resulted in a small but significant increase in whole body BMD compared to a decrease in the placebo group. The addition of calcium supplements may have a synergistic effect on the reduction of bone loss. Conclusion: Low dose estrogen, taken either orally or transdermally, can prevent or reverse postmenopausal bone loss and appears to be a useful alternative to higher dosages in the prevention and treatment of osteoporosis. The option of starting HRT at low dose gives physicians the ability to titrate doses to suit individual patients whilst ensuring adequate bone protection and the minimum of hyperestrogenic side effects.