CLINICAL RELEVANCE OF THE MEASUREMENT OF NON-COLLAGEN BONE PROTEINS IN SERUM OF SENILE OSTEOPOROTICS

Bone is a complex tissue in which continuous processes of formation and resorption of the bone ground substance take place, involving a great number of local and systemic factors. Many of the participating substances are present in general circulation, and measurements of their serum levels could give the physician useful information on bone turnover at any time. Non-collagen bone proteins are the best candidates for the role of markers of bone metabolism: among these, the most promising are bone gla-protein, alpha-2-HS-glycoprotein, and interleukin-1. Clinical application of bone biomarker measurements is at present limited by the fact that their precise function is not clear, and that the analytical methods have often low specificity. It should be stressed, however, that detection of osteoporosis is often difficult, and it is particularly true in elderly patients, who display various degrees of physiologic osteopeneia. The importance of biochemical indices of bone turnover in a better characterization of a silent osteoporosis should, therefore, not be overlooked.