Bone Alkaline Phosphatase Isoenzyme and Carboxy-Terminal Propeptide of Type-I Procollagen in Healthy Chinese Girls and Boys

Abstract

The bones of children grow at a faster rate during the first few years of childhood and puberty. Recently, advances in assays for biochemical markers of bone formation have provided noninvasive means to study bone growth and metabolism in children (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Because of the variations in the rate of bone growth in different age groups and possible ethnic differences, age-specific reference ranges for bone formation markers must be established in a particular pediatric population. Conventional bone formation markers such as osteocalcin (1) have been shown to correlate with serum concentrations of insulin-like growth factor-I and testosterone in children and adolescents. In pathological conditions, osteocalcin (2)(3)(4) is lower in growth hormone-deficient children and increases with replacement therapy. Osteocalcin, however, is labile and possesses problems in sample processing and storage (15). Recently, two other bone formation markers in serum, bone alkaline phosphatase isoenzyme (BAP) (16) and the carboxy-terminal propeptide of type-I procollagen (PICP) (17), were shown to be sensitive and specific markers …