title: The effect of sex, height and time of day on the excretion of glycosaminoglycans and the consequences.
abstract: A diurnal rhythm in the excretion of glycosaminoglycan-derived uronic acid with an increased excretion during daytime has been found in adults. Due to this rhythm a 24-h excretion was established as the optimum measurement of glycosaminoglycan turnover in tissue. Neither the excretion of uronic acid nor the uronic acid/creatinine ratio in the morning urine could predict the 24-h excretion of glycosaminoglycans as estimated by a statistical model. This model may also be of general interest in similar clinical problems. Compared with males, females had a lower excretion of glycosaminoglycans. Part of this discrepancy reflected a sex-difference in height, which was shown to be positively correlated with the excretion. On the other hand, the uronic acid/creatinine ratio was not influenced by height or sex. Body mass, age and urine output did not influence the ratio or the excretion of uronic acid.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001823:Body Composition; D001827:Body Height; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine; D005260:Female; D006025:Glycosaminoglycans / Q000652:urine*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D013223:Statistics as Topic; D014574:Uronic Acids / Q000652:urine
chemical_list: D006025:Glycosaminoglycans; D014574:Uronic Acids; D003404:Creatinine