Urinary total hydroxyproline: creatinine ratio. Range of normal, and clinical application in British children

The total hydroxyproline: creatinine ratio has been determined in random samples of urine collected from 1577 normal Bristol children and from children with hypothyroidism, growth hormone deficiency, coeliac disease, and rickets. The results in normal children had a profile similar to that of length velocity. When specific therapy was given to the children with growth failure there was a prompt increase in the total hydroxyproline: creatinine ratio, which occurred well before a growth spurt could be detected by anthropometry. The ratio could be a useful chemical adjunct to anthropometry and radiology in the assessment of normal and abnormal growth. The prompt response of the ratio to changes in growth rate suggests that it may be particularly useful in studying physiological variation in growth over short periods of time and in close monitoring of treatment regimens for growth failure. Random samples of urine may be used, automated methods of analysis are available, and other specialities find the investigation a useful one, so that for the paediatrician the urine total hydroxyproline: creatinine ratio has a potentially wide application.