Results of a stimulatory therapy of low bone metabolism in osteoporosis with (1-38)hPTH and diphosphonate EHDP. Protocol of study I, osteoporosis trial Hannover.

In contrast to prevention, the therapy of manifest osteoporosis remains a clinically significant problem. So far all therapeutic attempts have yielded unsatisfying results. For this reason we have tried to achieve a positive bone balance by sequential stimulation and inhibition of the osseous metabolism. The therapy consisted of six 14-day courses with 400 units (1–38)hPTH per day and, in addition, starting with the 2nd week of PTH therapy, EHDP 5 mg per kg body weight per day for a total of 2 weeks. Already the initial therapeutic course resulted in a stimulation of decreased bone metabolism which could be documented by an increase in the calcium-47 accretion rate (six patients). An increase of the alkaline phosphatase could be noted (four patients); this, however, did not correlate with the calcium accretion. A positive calcium balance could, nonetheless, only be attained in four of eight patients within this period, while neither the alkaline phosphatase nor the kinetics would allow a prediction of this effect. Changes of the balance coincided with equal changes in the net calcium absorption. The urinary calcium excretion increased temporarily during the therapeutic phase. We were not able to detect an influence on the vitamin D metabolites. Histomorphometric studies did not demonstrate an increase in bone mass in the iliac creast after six therapeutic courses. Nevertheless, progressive deformations of vertebral bodies did not occur. We conclude that already after 2 weeks this therapeutic concept can lead to a stimulation of bone metabolism.