Circadian Rhythm of the Total Hydroxyproline: Creatinine Ratio in Urine

Abstract

Circadian rhythm of the total hydroxyproline: creatinine ratio in urine C. A. MAUTALEN, Instituto de Investigaciones Medicas, Buenos Aires, 24 October 1973.In a recent paper in Clinical Science Dr Wharton et al. (1973,44,(359)(360)(361)(362)(363)(364)(365) found a significant correlation of both height and weight velocities with the total hydroxyproline : creatinine ratio (THP:Cr) in random urine samples from twenty-six adolescent boys. The validity of results obtained in random samples of urine is based on previous reports where THP:Cr of 24 h specimens was compared with the results obtained in spot samples from the same period. Howells, Wharton & McCance(1967) observed that the ratios were closely correlated (r = 0.98; P<O.OOl). Younoszai, Kacic, Dilling & Haworth (1969) found a good correlation for low values, but at higher ratios the spread was greater.

Hydroxyproline excretion in infantile gastroenteritis.

“…THP:Cr in 24-hour specimens of urine has been shown to be a more accurate measure of growth rate than total hydroxyproline alone (Allison et al, 1966), and further studies have shown a reasonable correlation of this ratio in random specimens with that in 24-hour collections (Howells et al, 1967;Younoszai et al, 1969). However, Mautalen (1974) has pointed out that hydroxyproline excretion and THP:Cr in adults is subject to diurnal variation and has questioned the validity of measurements on random specimens. Reviewing this controversy, Wharton (1974) noted that the variations in THP:Cr in children were small enough to make measurements on single specimens adequate for clinical purposes.…”