[Osteoporosis therapy and thyroid function. Influence of 6 months of sodium fluoride treatment on thyroid function and bone density].

26 women were treated for osteoporosis with 40 mg of sodium fluoride twice a day (equivalent 36 mg of fluorine) for a longer period. Mostly by reason of incompatibility, a reduction to half of the dose was necessary in six of these patients. The control of plasma fluoride concentration indicated that only 10 patients took their medicine regularly. Before treatment as well as three and six months after beginning of treatment the patients were examined. In these examinations bone density was measured across the middle phalanx of the middle finger with a I-125-profile scanner. Size and function of the thyroid gland were evaluated by clinical aspects and with in vivo- and in vitro-methods for thyroid diagnostic. The program includes also a check up with a 12 canal-serum-autoanalyzer. In 10 patients with warranted regular intake of the drug the increase of bone density was significant after three months already. In all 26 patients a considerable increase of the alkaline phosphatase after three months was evident. Under the influence of sodium fluoride no change was seen in function and size of thyroid gland. This result verifies the efficiency of sodium fluoride in osteoporosis-therapy without any measurable influence on thyroid function.