title: Urinary selenium excretion in infancy: comparison between term and preterm infants.
abstract: We evaluated the urinary excretion of selenium (Se), an essential component of glutathione peroxidase, in infants aged 1 week and 1, 4, and 7 months and examined the relationship between urinary Se and renal function. Daytime spot urine samples from a total of 80 infants were analyzed. The Se concentration in urine was measured by fluorometry, while the beta 2-microglobulin content, an index of renal tubular function, was determined by radioimmunoassay. In healthy term infants, the urinary Se excretion showed a peak level at 1 month of age. In contrast, the urinary Se concentration rapidly decreased in preterm infants from 1 week to 7 months postnatally. The level at 1 week in preterm infants was significantly higher than that in term infants, although the mean levels at 1, 4, and 7 months were lower in preterm infants. The level of urinary Se did not correlate significantly with the beta 2-micro-globulin concentration, either in term or preterm infants at any age investigated. Our results suggest that the renal excretion of Se probably reflects the body stores of Se and is not related directly to the renal function in infants. Urinary Se, a noninvasive marker of the Se status, may be used for diagnosis and follow-up of Se deficiency in infants.
authors.affiliation: Department of Pediatrics, Fukui Medical School, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tsukahara
authors.forename: Y
authors.initials: Y
authors.lastname: Deguchi
authors.forename: M
authors.initials: M
authors.lastname: Hiraoka
authors.forename: C
authors.initials: C
authors.lastname: Hori
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Kawamitsu
authors.forename: Y
authors.initials: Y
authors.lastname: Konishi
authors.forename: Y
authors.initials: Y
authors.lastname: Kusaka
authors.forename: M
authors.initials: M
authors.lastname: Sudo
mesh_terms: D000375:Aging / Q000652:urine; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000652:urine*; D007668:Kidney / Q000502:physiology; D008297:Male; D012016:Reference Values; D012643:Selenium / Q000652:urine*; D001613:beta 2-Microglobulin / Q000652:urine
chemical_list: D001613:beta 2-Microglobulin; D003404:Creatinine; D012643:Selenium