title: Small birth weight and later body composition and fat distribution in adolescents: the Avena study.
abstract: OBJECTIVE
  To assess the association between birth weight and body composition and fat distribution in adolescents, and to test the possible sex-specific effect in these relationships.
  
  
  METHODS
  A total of 1,223 adolescents 13-18.5 years old (553 male adolescents and 670 female adolescents) born at >35 weeks, were selected from a cross-sectional multicenter study conducted in five Spanish cities in 2000-2002. BMI was calculated from weight and height. Triceps and subscapular skinfold thickness (ST) were measured on the left side, and fat mass (FM) and fat-free mass (FFM) were estimated according to the equations of Slaughter et al. Subscapular skinfold adjusted by tricipital (ST) and waist circumference were used as markers of central adiposity.
  
  
  RESULTS
  Birth weight Z-score was positively associated with FFM in female adolescents (P<0.001), but not in male adolescents, after controlling for age, pubertal stage, gestational age, socioeconomic status, physical activity, and current height (P<0.001 for interaction between adjusted birth weight Z-score and sex). Adjusted birth weight Z-score was inversely associated with central adiposity in male and female adolescents as measured by ST (P=0.026).
  
  
  CONCLUSIONS
  These results provide further evidence that gender has an important influence on the programming effect of birth weight on later FFM in adolescents because the effect was only observed in female adolescents. Our results suggest that small size for gestational age at birth could program more central subcutaneous fat deposition in adolescents of both sexes, but further research is needed on this issue.
authors.affiliation: Department of Nutrition and Food Science, University of the Basque Country, Vitoria, Spain. idoia.labayen@ehu.es
authors.forename: Idoia
authors.initials: I
authors.lastname: Labayen
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.forename: Jonatan R
authors.initials: JR
authors.lastname: Ruiz
authors.forename: Marcela
authors.initials: M
authors.lastname: González-Gross
authors.forename: Julia
authors.initials: J
authors.lastname: Wärnberg
authors.forename: Christina
authors.initials: C
authors.lastname: Breidenassel
authors.forename: Francisco B
authors.initials: FB
authors.lastname: Ortega
authors.forename: Ascensión
authors.initials: A
authors.lastname: Marcos
authors.forename: Manuel
authors.initials: M
authors.lastname: Bueno
mesh_terms: D050154:Adiposity; D000293:Adolescent; D041923:Adolescent Development; D001724:Birth Weight; D001823:Body Composition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D012737:Sex Factors; D012885:Skinfold Thickness; D013030:Spain; D050151:Subcutaneous Fat / Q000254:growth & development*