A comparison of teriparatide and calcitonin therapy in postmenopausal Asian women with osteoporosis: a 6-month study

OBJECTIVE: The number of hip fractures is expected to double in the next 20 years, with current estimates that Asia will account for 37% of these cases. As bone mineral density (BMD) may be used as a measure of fracture risk, we sought to compare the effects of teriparatide with salmon calcitonin treatment on changes in BMD, biochemical bone markers, and safety in postmenopausal Asian women with osteoporosis.
METHODOLOGY: A total of 104 patients (n = 47 teriparatide [20 g/day subcutaneously] and n = 57 calcitonin [100 IU/day subcutaneously]) were enrolled in Hong Kong, Singapore, Philippines, Malaysia, and Thailand. Calcium (> or = 500 mg/day) and vitamin D (200-400 IU/day) supplements were taken throughout the 6-month controlled, randomized study.
RESULTS: Teriparatide was associated with a 5.03 +/- 4.77% increase in lumbar spine BMD (p < 0.0001, mean +/- SD change from baseline), whereas changes in lumbar spine BMD for patients on calcitonin were not statistically significant (mean change of 0.36 +/- 4.12%, p = 0.16). Comparison of the two groups indicated that teriparatide treatment improved lumbar spine BMD statistically significantly more than calcitonin (p < 0.0001). No statistically significant changes were observed for total hip or femoral neck BMD. Serum bone-specific alkaline phosphatase (BSAP) increased by 55.9% (median change from baseline, p < 0.0001) in the teriparatide group, and remained stable with calcitonin (5.0% change, p = 0.24); osteocalcin increased by 156.15% (median change from baseline, p < 0.0001) with teriparatide, and decreased with calcitonin (-15.25%, p = 0.03). Similar rates of adverse events were observed, with nausea and dizziness the most commonly reported for both groups (teriparatide versus calcitonin, 13.0% versus 23.2% p = 0.21, 10.9% versus 21.4% p = 0.19, respectively). There were no clinically relevant changes observed in laboratory parameters.
CONCLUSIONS: Both treatments were similarly tolerated, however teriparatide was associated with greater increases in lumbar spine BMD and bone formation markers, demonstrating the unique mechanism of action and safety of this treatment for osteoporosis in these Asian women.