[Osteoporosis at high remodeling and parathyroid function. Histo-biological confrontations (author's transl)]

In order to evaluate the relationship between apparently idiopathic osteoporosis and parathyroid hormone secretion, plasma immunoreactive parathyroid hormone (iPTH) was measured in 57 untreated osteoporotic patients using a carboxyl-terminal specific antiserum, and sections of undecalcified iliac bone biopsies from these subjects, who had been previously doubly labelled with tetracycline, were quantitatively analysed. Twenty-one patients (36%) exhibited histological signs of a high remodeling similar to that which is present in primary hyperparathyroidism, but their osteoplastic appositional rate values were lower. Among these 21 cases 8 had an increase of their iPTH levels. These data and those of the literature indicate that in a few cases high remodeling osteoporosis may be associated with parathyroid hypersecretion, but do not bring out the evidence that the increased circulating iPTH is the cause of osteoporosis. The authors draw from their results some practical consequences for the treatment of high remodeling osteoporosis.