title: Periodicity of urinary beta-2-microglobulin excretion.
abstract: Using the cosinor system we examined the chronobiology of urinary beta-2-microglobulin excretion. The following dimensions were studied: urinary volume, creatinine concentration, creatinine excretion, beta-2-microglobulin concentration, beta-2-microglobulin excretion and the beta-2-microglobulin/creatinine ratio. Urinary volume showed an acrophase at 1704 hours (p = less than 0.01), creatinine concentration showed an acrophase at 0512 hrs (p = less than 0.006) and the beta-2-microglobulin/creatinine ratio presented an acrophase at 1736 hrs (p = less than 0.03). Data were related to a tau = 24 hrs. The data clearly reveal that the beta-2-microglobulin/creatinine ratio shows a circadian rhythm in urinary excretion.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine; D006801:Humans; D008657:Metabolic Clearance Rate; D001613:beta 2-Microglobulin / Q000652:urine*
chemical_list: D001613:beta 2-Microglobulin; D003404:Creatinine