Calcium-47 kinetic measurements of bone turnover compared to bone histomorphometry in osteoporosis: the influence of human parathyroid fragment (hPTH 1-34) therapy.

Nineteen patients with involutional osteoporosis have been studied by means of combined 47Ca kinetic and calcium balance studies and morphometric analysis of iliac crest bone biopsies taken after double tetracycline labelling. Fifteen of them, together with three additional patients, were restudied after at least six months treatment with human parathyroid hormone fragment (hPTH 1-34). A close inverse relationship was found in the untreated patients between trabecular resorption surfaces (RS%) and calcium balance. The kinetically determined resorption rate showed a significant positive correlation with RS%, while the product of surface osteoid (SO%) and calcification rate (CR), determined from the tetracycline double label, correllated significantly with the 47Ca accretion rate. When the data from the patients on treatment were examined the relationship between calcium balance and RS% persisted; but the increased scatter in values for trabecular bone volume (TBV%) following the positive response of some patients to therapy appeared to contribute to a weakening in all these relationships. This was partially corrected by allowing for variations in TBV in calculating the remaining regressions. Osteoclast numbers correlated well with both accretion and resorption rates but not with calcium balance. Only a minor part of the scatter associated with these statistical associations could be accounted for by methodological uncertainties; nevertheless in this homogeneous group of patients fair predictions of kinetic indices could be made from histomorphometric data and vice versa. The remainder of the scatter is likely to be due to variations in turnover between different sites in the skeleton, particularly between cortical and trabecular bone; and to the tendency of kinetic parameters to include a variable contribution from exchange processes which can only be corrected by more sophisticated techniques for measuring the formation rate of new bone with radioisotopes. © 1981 S.N.P.M.D. Paris

Calcium-47 kinetic measurements of bone turnover compared to bone histomorphometry in osteoporosis: the influence of human parathyroid fragment (hPTH 1-34) therapy.

Nineteen patients with involutional osteoporosis have been studied by means of combined 47Ca kinetic and calcium balance studies and morphometric analysis of iliac crest bone biopsies taken after double tetracycline labelling. Fifteen of them, together with three additional patients, were restudied after at least six months treatment with human parathyroid hormone fragment (hPTH 1-34). A close inverse relationship was found in the untreated patients between trabecular resorption surfaces (RS%) and calcium balance. The kinetically determined resorption rate showed a significant positive correlation with RS%, while the product of surface osteoid (SO%) and calcification rate (CR), determined from the tetracycline double label, correllated significantly with the 47Ca accretion rate. When the data from the patients on treatment were examined the relationship between calcium balance and RS% persisted; but the increased scatter in values for trabecular bone volume (TBV%) following the positive response of some patients to therapy appeared to contribute to a weakening in all these relationships. This was partially corrected by allowing for variations in TBV in calculating the remaining regressions. Osteoclast numbers correlated well with both accretion and resorption rates but not with calcium balance. Only a minor part of the scatter associated with these statistical associations could be accounted for by methodological uncertainties; nevertheless in this homogeneous group of patients fair predictions of kinetic indices could be made from histomorphometric data and vice versa. The remainder of the scatter is likely to be due to variations in turnover between different sites in the skeleton, particularly between cortical and trabecular bone; and to the tendency of kinetic parameters to include a variable contribution from exchange processes which can only be corrected by more sophisticated techniques for measuring the formation rate of new bone with radioisotopes. © 1981 S.N.P.M.D. Paris