Analysis of skeletal development on the basis of body mass and bone resorption

Regression analysis was utilized to define the relationships among body wei ght, whole skeleton bone resorption (H-3-tetracycline method), and the deve lopment of skeletal mass. The results indicated that skeletal development ( % body weight) of slowly growing, 24-week-old rats consisted of two major c omponents, one directly (r = 0.985, P < 0.001) and one inversely (r = 0.977 , P < 0.001) related to body weight. It was further noted that the skeletal resorption rate was inversely correlated to body weight (r = 0.879, P < 0. 05) and directly related to skeletal development (r = 0.865, P < 0.05), sug gesting that whole skeleton bone resorption and formation were highly corre lated in the slowly growing animal. A third small component of skeletal dev elopment identified in the analysis of data from 24-week-old animals, showe d no direct relationship to either body weight or resorptive activity. The model presented enables the separation of skeleton mass into major componen ts which may represent mechanically and metabolically driven bone formation . (C) 2000 Elsevier Science Inc. All rights reserved.