RT Journal Article SR Electronic T1 Urinary excretion of pyridinium crosslinks in healthy 4–10 year olds JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 370 OP 373 DO 10.1136/adc.80.4.370 VO 80 IS 4 A1 Husain, Shahid M A1 Mughal, Zulf A1 Williams, Gwen A1 Ward, Kate A1 Smith, Colin S A1 Dutton, John A1 Fraser, William D YR 1999 UL http://adc.bmj.com/content/80/4/370.abstract AB Urinary pyridinoline and deoxypyridinoline, pyridinium crosslinks released during breakdown of mature collagen, might serve as useful markers of bone resorption. Before their role can be identified, reference values must be established. In this study, free pyridinoline (f-Pyr), free deoxypyridinoline (f-DPyr), and creatinine (Cr) were measured in first morning void urine samples from 250 girls and 265 boys between the ages of 4 and 10 years. Overall, there was a decrease in f-Pyr:Cr and f-DPyr:Cr ratios with increasing age in both sexes, but there was a wide range of values for individuals of similar ages. Further studies are required to assess whether urinary pyridinium crosslink excretion is sufficiently deranged in conditions affecting bone metabolism for the measurement of these compounds to be of clinical value.