Bone turnover and balance evaluated by a combined calcium balance and 47calcium kinetic study and dynamic histomorphometry.

Bone resorption and formation rates were evaluated at the organ level using calcium kinetic methods and at the trabecular bone tissue level using dynamic histomorphometry in 20 patients with various metabolic bone diseases (primary hyperparathyroidism (N = 9), hyperthyroidism (N = 6), and hypothyroidism (N = 5). Highly significant correlations were demonstrated between resorption and formation rates at organ level (r = .90, P less than .001) and at tissue level (volume referent) (r = .93, P less than .001), indicating a high degree of coupling between resorption and formation within the three disease states. Tissue level resorption rates (surface referent, as well as volume referent) both correlated significantly (P less than .01) to organ level resorption rate (r = .60 and r = .63, respectively). Fractional active resorption surface and cellular level resorption rate did not reveal significant correlations to calcium kinetic estimates. No correlation could be demonstrated between organ level mineralization rate and formative or labeled trabecular surfaces. However, all tetracycline based tissue level formation rates revealed highly significant correlations (P less than .01) to organ level mineralization rate (calcification rate, r = .71; surface referent bone formation rate, r = .59; volume referent bone formation rate, r = .68). Based on histomorphometric parameters for resorption and formation, actual and predicted tissue level trabecular bone balances were calculated. Both the actual and predicted bone balance correlated significantly to the organ level calcium balance (P less than .05). Correction for skeletal size based on BMC measurements did not improve any of the correlations significantly.(ABSTRACT TRUNCATED AT 250 WORDS)