[Comparison of the effectiveness of 17-beta-estradiol and calcitonin in women with postmenopausal bone loss]

Abstract

Background: The objective of this study was to compare effects of 17 beta-estradiol and intranasal salmon calcitonin on bone mass and biochemical markers of bone turnover in postmenopausal women with an accelerated bone loss and osteopenia or osteoporosis.

Methods and results: 72 women with significantly increased bone resorption were evaluated (urinary hydroxyproline/creatinine > or = 21.9 mmol/mol, mean age, 53.7 +/- 6.3 years, time since menopause 6.1 +/- 2.6 years). All patients received daily 500 mg Ca2+ and 400 IU vitamin D supplement. 48 patients with osteopenia and 24 patients with osteoporosis were randomly allocated to treatment with open-label 17 beta-estradiol (50 micrograms transdermally or 2 mg orally) or calcitonin (200 IU every other day). Bone mass was measured by dual-energy x-ray absorptiometry (DPX-L, Lunar, C.V., 1.10 +/- 0.55% and 1.41 +/- 0.55%, lumbar spine and femoral neck, respectively) every six month for 2.5 year, bone stiffness was measured by ultrasound (Achilles, Lunar, C.V., 3.88 +/- 1.95%). Biochemical markers of bone turnover (plasma osteocalcin and tartrate-resistant acid phosphatase, serum bone specific alkaline phosphatase and urinary hydroxyproline) were measured before and after 6, 12 and 24 month of treatment. Patients who received 17 beta-estradiol experienced significant increases (p < 0.05) in bone mass on the first and second year (by 2.6% and 2.1% at lumbar spine, 1.1% and 1.0%, at femoral neck, and 2.3% and 2% at the heel). A significant positive correlation was found between rates of bone mass change in all sites (p < 0.001). No statistically significant bone changes were found in calcitonin treated patients. In 17 beta-estradiol treated patients, biochemical markers of bone turnover decreased by 40-50% to the mean values in premenopausal women. In calcitonin treated patients, biochemical markers reached the upper normal limit.

Conclusions: Estrogen replacement therapy increases bone mass in lumbar spine as well as in femoral neck. It is efficient for both prevention and treatment of postmenopausal osteoporosis. Salmon calcitonin effectively prevents bone loss. Efficacy of both the treatment can be assessed after 6 months using a biochemical marker of bone resorption and after 2 years using dual-energy x-ray densitometry.