17β-Estradiol and Continuous Norethisterone: A Unique Treatment for Established Osteoporosis in Elderly Women

Abstract

Forty women aged 64.7 +/- 5.1 yr with established postmenopausal osteoporosis were blindly allocated to 1 yr's treatment with either continuous combined estrogen/progestogen therapy (2 mg estradiol + 1 mg norethisterone acetate + 500 mg calcium daily) or placebo + 500 mg calcium daily. In the group treated with hormones bone mineral density in the spine (dual photon absorptiometry) and bone mineral content in the ultradistal forearm (single photon absorptiometry) increased highly significantly by 8-10% during the 1 yr of treatment. Bone mineral content in the mid-shaft of the forearm (single photon absorptiometry) and the total body bone mineral (dual photon absorptiometry) increased by 3-5% when compared to that in the placebo group, which showed virtually unchanged values at all measurement sites. Seven of the women treated with hormones were examined after a further year of treatment. BMC increased by another 3-6%, reaching a 12% increase in bone mineral density in the spine after 2 yr of treatment. Biochemical estimates of bone resorption (fasting urinary calcium and hydroxyproline) and bone formation (serum alkaline phosphatase and plasma osteocalcin), decreased significantly (P less than 0.001) in the group treated with hormones, but remained unchanged in the placebo group. The reduction in indices of bone resorption was more pronounced than that in bone formation after one year, indicating a positive bone balance. No further changes were seen in these bone turnover parameters during the second year of treatment. In the group treated with hormones, serum levels of triglycerides, total cholesterol, and low density lipoprotein cholesterol decreased by about 12% (P less than 0.05-P less than 0.01), whereas high density lipoprotein cholesterol decreased by about 8% (P less than 0.001). The high density lipoprotein cholesterol/low density lipoprotein cholesterol ratio was unchanged. The hormone treatment did not produce any major side effects, and only minor bleedings were experienced by a few women. The present study demonstrates that treatment with female sex hormones in this particular combination is a realistic approach to the treatment of women with established postmenopausal osteoporosis.