Effects of the combined use of calcitonin and 1α-hydroxycholecalciferol on vertebral bone loss and bone turnover in women with postmenopausal osteopenia and osteoporosis:

Abstract Objectives: The present study investigates the effect of long-term and continuous treatment with low dose calcitonin in combination with 1α-hydroxycholecalciferol on vertebral bone mass in early postmenopausal women. Methods: A total of 202 postmenopausal women between 53 and 58 years of age were recruited individually and randomly assigned to one of four groups. Comparisons were made among groups of women receiving calcitonin alone (10 IU I.M. twice a month), 1α-hydroxycholecalciferol alone (0.5 μg orally twice daily), a combination of the above two agents, or no treatment. Bone mineral density (BMD) of lumber spine (L2–4) was determined using Dual Energy X-ray Absorptiometry. The study was carried out prospectively over a 2-year period. Results: We observed a significant increase in vertebral bone mass in the combined treatment regimen of calcitonin and 1α-hydroxycholecalciferol (3.44% at 12 months in the combination group vs 1.40, 0.92, and −0.70% in the calcitonin alone, 1α-hydroxycholecalciferol alone, and control groups, respectively; 4.51% at 24 months in the combination group vs 2.21, 1.04, and −3.61% in the calcitonin alone, 1α-hydroxycholecalciferol alone, and control groups, respectively). Serum PTH, osteocalcin levels and alkaline phosphatase activity decreased significantly within 12 months whereas urinary pyridinoline/creatinine ratio decreased at 24 months in the combination group. We observed mild adverse effects in 25.0% (7/28) and 30.0% (6/20) of combination regimen and cacitonin treatment cases, respectively. Conclusions: The results of the study suggest that the combination treatment regimen increased vertebral bone loss in early postmenopausal women to a greater extent than did calcitonin alone or 1α-hydroxycholecalciferol alone.