title: Recognition of a sequence: more growth before birth, longer telomeres at birth, more lean mass after birth.
abstract: Telomere length at birth is a major determinant of telomere length in late adulthood. However, the prenatal setting of telomere length is poorly understood. Individuals born large from non-diabetic mothers are at lower risk for later-life disorders than those born small, a feature of their longer health span being a higher lean mass that provides more muscle strength and that is already present in infancy.
  
  
  
  At birth, we studied leukocyte telomere length (by quantitative polymerase chain reaction) in 103 small-for-gestational-age, appropriate-for-gestational-age or large-for-gestational-age (SGA, AGA or LGA) infants born after uncomplicated, term, singleton pregnancies. All infants were breastfed for ≥4 months. At 2 weeks and 12 months, body composition was assessed by dual X-ray absorptiometry.
  
  
  
  Telomere lengths were shorter in SGA newborns and longer in LGA newborns than in AGA newborns (P < 0.001), also after adjustment for maternal age, pre-gestational body mass index, gestational weight gain and gestational age. Telomere length at birth associated (all P ≤ 0.001) to birthweight (r = 0.50) and to both lean mass (r = 0.43) and fat mass (r = 0.48) at age 2 weeks, but only to lean mass at 12 months (r = 0.51).
  
  
  
  Higher weight and longer telomeres at birth are followed by more lean mass in late infancy. Relatively large, breastfed infants from non-diabetic mothers may become models of how to make a healthy start.
authors.affiliation: Department of Development & Regeneration, University of Leuven, Leuven, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: de Zegher
authors.affiliation: Institut de Recerca Pediàtrica Hospital Sant Joan de Déu (IRP-HSJD), University of Barcelona, Esplugues, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Díaz
authors.affiliation: Department of Pediatrics, Dr. Josep Trueta Hospital, Girona, Spain.|Girona Institute for Biomedical Research, Girona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Lopez-Bermejo
authors.affiliation: Institut de Recerca Pediàtrica Hospital Sant Joan de Déu (IRP-HSJD), University of Barcelona, Esplugues, Barcelona, Spain.|Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Ibáñez
mesh_terms: D015502:Absorptiometry, Photon; D001724:Birth Weight / Q000235:genetics* / Q000502:physiology; D001823:Body Composition / Q000235:genetics* / Q000502:physiology; D015992:Body Mass Index; D005260:Female; D047109:Fetal Development / Q000235:genetics*; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D016615:Telomere / Q000378:metabolism*; D015430:Weight Gain
keywords: fat mass; fetal growth; lean mass; telomere