title: Impact of gestational age, sex, and postnatal age on urine biomarkers in premature neonates.
abstract: BACKGROUND
  Urine proteins may help in understanding physiology and diagnosing disease in premature infants. Determining how urine proteins vary by degree of prematurity, sex, and postnatal day is warranted.
  
  
  METHODS
  We performed a prospective cohort study to assess the independent correlation of 14 urine biomarkers (measured on postnatal days 1-4) with gestational age (GA), sex, and postnatal age in 81 premature infants (mean, 1017 g) without acute kidney injury using a random-effects mixed model.
  
  
  RESULTS
  Neutrophil gelatinase-associated lipocalin (NGAL) and vascular endothelial growth factor (VEGF) showed significant associations for sex, GA, and postnatal age. Cystatin C, osteopontin (OPN), and trefoil factor 3 (TFF3) were associated with postnatal age and GA, but not sex. Epithelial growth factor (EGF) and uromodulin were associated with GA only. Clusterin was associated with postnatal age and sex. Albumin was associated with sex only. Beta-2-microglbulin (B2M), osteoactivin, kidney injury molecule -1 (KIM-1), and alpha glutathione S-transferase (αGST) were associated with postnatal age only.
  
  
  CONCLUSIONS
  Postnatal age affects B2M, cystatin C, NGAL, OPN, clusterin, Kim-1, osteoactivin, TFF3, VEGF, αGST. GA affects cystatin C, EGF, NGAL, OPN, UMOD, TFF3, and VEGF. Sex affects albumin, NGAL, and clusterin. Interpretation of urine biomarkers will need to account for these associations.
authors.affiliation: Division of Pediatric Nephrology Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Ave S, Lowder 516, Birmingham, AL, 35233, USA.
authors.forename: Behtash
authors.initials: B
authors.lastname: Saeidi
authors.affiliation: Division of Pediatric Nephrology Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Ave S, Lowder 516, Birmingham, AL, 35233, USA.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Koralkar
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham, 1665 University Blvd. Ryals Public Health Building Room 220, Birmingham, AL, 35294-0022, USA.
authors.forename: Russell L
authors.initials: RL
authors.lastname: Griffin
authors.affiliation: Division of Pediatric Nephrology Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Ave S, Lowder 516, Birmingham, AL, 35233, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Halloran
authors.affiliation: Division of Neonatology Department of Pediatrics, University of Alabama at Birmingham, 1700 Sixth Avenue South, Birmingham, AL, 35249, USA.
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Ambalavanan
authors.affiliation: Division of Pediatric Nephrology Department of Pediatrics, University of Alabama at Birmingham, 1600 7th Ave S, Lowder 516, Birmingham, AL, 35233, USA. daskenazi@peds.uab.edu.
authors.forename: David J
authors.initials: DJ
authors.lastname: Askenazi
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000652:urine*; D019102:Infant, Very Low Birth Weight / Q000652:urine*; D008297:Male; D011446:Prospective Studies; D012727:Sex Characteristics
chemical_list: D015415:Biomarkers
keywords: Acute kidney injury; Acute renal failure; Baseline; Cystatin C; Infant; KIM-1; NGAL; Reference