Combination-Therapy with 1–38 hPTH and Calcitonin Increases Vertebral Density in Osteoporotic Patients

Abstract

We have investigated a combined PTH-Calcitonin therapy to enhance reduced bone mass in osteoporotic patients. Previous therapy protocols using calcium, vitamin D, estrogen, sodium fluoride, or combinations of these drugs, have not been successful in enhancing bone mass more than 10% in one year especially in low turn-over states. Studies using anabolic doses of the PTH fragment 1–34 hPTH have produced modest gains documented by histmorphometry. A recent report of Slovik et al. (1) clearly showed PTH to be effective in enhancing vertebral bone density, measured by quantitated computed tomography (QCT). Rasmussen et al. (2) proposed to additionally reduce bone resorption by combing the phosphate stimulated endogenous PTH secretion with calcitonin injections. This concept was effective in enhancing trabecular bone mass on histomorphometric analysis. Others described the addition of calcitonin to PTH treatment not being effective (3, 1). The objective of our study was to develop a novel approach to combination therapy (see patient and study design). N-terminal PTH and nasally applied calcitonin were used to induce a positive bone balance in osteoporotic patients. Changes in bone density were monitored by quantitative CT-methods (QCT).