title: Timing of solid food introduction is associated with urinary F2-isoprostane concentrations in childhood.
abstract: BACKGROUND
  Timing of solid food introduction in infancy has been associated with several chronic diseases. To explore potential mechanisms, we investigated the relationship between timing of solid food introduction and F2-isoprostanes-a marker of oxidative stress.
  
  
  METHODS
  Urinary F2-isoprostanes were assessed in 336 healthy children aged less than 11.5 y with 1,266 clinic visits (mean = 3.8 visits per child) in the Diabetes Autoimmunity Study in the Young. We analyzed the association between F2-isoprostane concentrations and infant diet exposures using linear mixed models adjusted for age, age(2), HLA-DR3/4,DQB1*0302 genotype, first-degree relative with type 1 diabetes, maternal age, maternal education, sex, and exposure to in utero cigarette smoke.
  
  
  RESULTS
  Later solid food introduction was associated with lower F2-isoprostane concentrations in childhood (on average, 0.10 ng/mg per month of age at introduction; estimate: -0.10 (95% confidence interval (CI): -0.18, -0.02) P value = 0.02). Moreover, childhood F2-isoprostane concentrations were, on average, 0.24 ng/mg lower in individuals breastfed at solid food introduction (estimate: -0.24 (95% CI: -0.47, -0.01) P value = 0.04) compared with those who were not. Associations remained significant after limiting analyses to F2-isoprostanes after 2 y of age.
  
  
  CONCLUSIONS
  Our results suggest a long-term protective effect of later solid food introduction and breastfeeding at solid food introduction against increased F2-isoprostane concentrations throughout childhood.
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado.
authors.forename: Brittni N
authors.initials: BN
authors.lastname: Frederiksen
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Seifert
authors.affiliation: Department of Biostatistics & Informatics, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado.
authors.forename: Miranda
authors.initials: M
authors.lastname: Kroehl
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado.
authors.forename: Molly M
authors.initials: MM
authors.lastname: Lamb
authors.affiliation: Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Ginger L
authors.initials: GL
authors.lastname: Milne
authors.affiliation: Barbara Davis Center for Diabetes, Aurora, Colorado.
authors.forename: Marian
authors.initials: M
authors.lastname: Rewers
authors.affiliation: Department of Epidemiology, Colorado School of Public Health, University of Colorado Denver, Aurora, Colorado.
authors.forename: Jill M
authors.initials: JM
authors.lastname: Norris
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000652:urine; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D028441:F2-Isoprostanes / Q000652:urine*; D005248:Feeding Methods / Q000009:adverse effects; D005260:Female; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000009:adverse effects; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D065840:Protective Factors; D012307:Risk Factors; D013997:Time Factors
chemical_list: D015415:Biomarkers; D028441:F2-Isoprostanes