Urinary Excretion of Pyridinoline and Deoxypyridinoline in Children

Abstract

Pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) are intermolecular crosslinking compounds in mature collagen and have been utilized as biomedical markers of bone resorption. We determined the reference ranges of urinary Pyr and D-Pyr in 358 normal children aged 6-14 years, and investigated urinary secretion of these pyridinolines in 16 patients with various growth disorders (7 with precocious puberty, 6 with Turner syndrome, and 3 with GH deficiency). The Pyr and D-Pyr levels in first morning void urine samples were measured by a high performance liquid chromatography (HPLC) assay. The age related changes in urinary pyridinolines were similar to growth velocity curves, reached peak levels at 11-12 years and decreased thereafter. Significant positive correlations were observed between growth velocities and urinary Pyr levels in both normal children and patients with growth disorders. These findings suggest that urinary pyridinolines are good markers of bone remodeling and might be useful in estimating and predicting growth in both normal children and patients with growth disorders.