Effects of one-year hormone replacement therapy on peripheral bone mineral content in patients with osteoporotic spine fractures

Abstract. A double-blind, placebo-controlled study on 31 patients with osteoporotic spine fractures was performed in order to assess the effects of one-year cyclical estrogen/gestagen replacement therapy (Trisequens, Novo) on peripheral bone mineral content and bone turnover. Bone mineral content was measured by single-photon absorptiometry with 125 I before, and 6 and 12 months after start of therapy. Calcium, phosphate, alkaline phosphatase, parathyroid hormone, calcidiol, calcitonin and 2-hour urinary hydroxyproline excretion were measured to evaluate bone turnover. After 12 months, forearm bone mineral content showed a significant increase (p<0.02) in the treatment group, whereas in the control group no statistically significant change in peripheral bone mass was observed. Parameters of bone metabolism showed a decrease in hydroxyproline excretion (p<0.02) as well as alkaline phosphatase (p<0.01) and no changes in parathyroid hormone, calcidiol, and calcitonin. These results demonstrate that one-year cyclical estrogen/gestagen replacement therapy improves peripheral bone mineral content measured by single-photon absorptiometry. This effect appears to be induced by an inhibition of bone resorption.