title: Circadian variation of serum urea concentration in north Indian subjects.
abstract: Circadian rhythm of serum urea concentration was studied in 25 clinically healthy, diurnally active, nocturnally resting young male Indians. The mean urea concentration was observed to be 22.32 mg/dl at 0800 h which increased gradually reaching maximum at 0000 h with a mean of 31.00 mg/dl. A marked circadian variation in serum urea was recorded with a statistically significant amplitude and acrophase at 2232 h (Cosinor analysis). The observation that serum urea concentration oscillates physiologically in the peripheral blood according to a circadian rhythm may prove to be of importance in the clinical interpretation of values at different times along the 24 h light-dark period.
authors.affiliation: Department of Biochemistry, B.R.D. Medical College, Gorakhpur.
authors.forename: R K
authors.initials: RK
authors.lastname: Singh
authors.forename: Y
authors.initials: Y
authors.lastname: Singh
authors.forename: R
authors.initials: R
authors.lastname: Srivastava
mesh_terms: D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D007194:India; D008297:Male; D012016:Reference Values; D014508:Urea / Q000097:blood*
chemical_list: D014508:Urea