title: Circadian rhythm of urinary beta 2 microglobulin excretion in patients with a nephrotic syndrome.
abstract: The changes in urinary beta 2 microglobulin excretion during the day were studied in 20 patients with a nephrotic syndrome under standardized conditions and compared with the known circadian variations in urinary albumin excretion in the same patients. Fifteen of the 20 patients (75%) had a circadian rhythm for beta 2 microglobulin in the urine. Phase as well as relative amplitude of the beta 2 microglobulin circadian rhythm varied between patients. In addition, its presence, normality, amplitude and phase were largely different from the albumin rhythm. Observations made in 10 healthy individuals suggest that day-night variability in the excretion of beta 2 microglobulin and albumin in the urine is also present in the absence of clinically important proteinuria. Circadian variations in urinary beta 2 microglobulin excretion are found in a majority of the patients with nephrotic syndrome and as they differ in several respects from the day-night fluctuation in urinary albumin excretion the mechanism is probably different.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000419:Albuminuria; D002940:Circadian Rhythm; D003404:Creatinine / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000652:urine*; D011507:Proteinuria / Q000652:urine; D001613:beta 2-Microglobulin / Q000652:urine*
chemical_list: D001613:beta 2-Microglobulin; D003404:Creatinine