title: Even transient rapid infancy weight gain is associated with higher BMI in young adults and earlier menarche.
abstract: BACKGROUND
  Early postnatal rapid 'catch-up' weight gain has been consistently associated with subsequent higher obesity risk and earlier pubertal development. In many low- and middle-income countries, infancy catch-up weight gain is transient and often followed by growth faltering. We explored the hypothesis that even transient catch-up weight gain during infancy is associated with later obesity risk and earlier puberty.
  
  
  METHODS
  A total of 2352 (1151 male, 1201 female) black South African children in the birth to twenty prospective birth cohort study (Johannesburg-Soweto) underwent serial measurements of body size and composition from birth to 18 years of age. At the age of 18 years, whole-body fat mass and fat-free mass were determined using dual-energy X-ray absorptiometry. Pubertal development was assessed by the research team between ages 9 and 10 years, and it was recorded annually from the age of 11 years using a validated self-assessment protocol.
  
  
  RESULTS
  Catch-up weight gain from birth to the age of 1 year, despite being followed by growth faltering between ages 1 and 2 years, was associated with greater mid-upper arm circumference (P=0.04) and skinfold thickness (P=0.048) at 8 years of age, and with higher weight (P<0.001) and body mass index (P=0.001) at 18 years of age after adjustment for sex, age, smoking during pregnancy, birth order, gestational age, formula-milk feeding and household socio-economic status. Infancy catch-up weight gain was also associated with younger age at menarche in girls (P<0.001). This association persisted after adjustment for smoking during pregnancy, birth order, gestational age, formula-milk feeding and household socio-economic status (P=0.005).
  
  
  CONCLUSIONS
  Transient catch-up weight gain from birth to the age of 1 year among children born in a low-income area of South Africa was associated with earlier menarche and greater adiposity in early adulthood. This observation suggests that modifiable determinants of rapid infancy weight gain may be targeted in order to prevent later obesity and consequences of earlier puberty in girls.
authors.affiliation: 1] University Department of Paediatrics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK [2] Department of General Paediatrics, Neonatology and Paediatric Cardiology, University Children's Hospital Düsseldorf, Düsseldorf, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Salgin
authors.affiliation: Medical Research Council/Wits Developmental Pathways for Health Research Unit, School of Medicine, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: S A
authors.initials: SA
authors.lastname: Norris
authors.affiliation: University Department of Paediatrics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.
authors.forename: P
authors.initials: P
authors.lastname: Prentice
authors.affiliation: Medical Research Council/Wits Developmental Pathways for Health Research Unit, School of Medicine, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: J M
authors.initials: JM
authors.lastname: Pettifor
authors.affiliation: 1] Medical Research Council/Wits Developmental Pathways for Health Research Unit, School of Medicine, University of the Witwatersrand, Johannesburg, South Africa [2] Human Sciences Research Council, Durban, South Africa.
authors.forename: L M
authors.initials: LM
authors.lastname: Richter
authors.affiliation: 1] University Department of Paediatrics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK [2] Medical Research Council Epidemiology Unit, Cambridge, UK.
authors.forename: K K
authors.initials: KK
authors.lastname: Ong
authors.affiliation: 1] University Department of Paediatrics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK [2] Medical Research Council/Wits Developmental Pathways for Health Research Unit, School of Medicine, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: D B
authors.initials: DB
authors.lastname: Dunger
mesh_terms: D015502:Absorptiometry, Photon; D050154:Adiposity / Q000502:physiology; D000293:Adolescent; D000367:Age Factors; D001724:Birth Weight / Q000502:physiology; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008572:Menarche / Q000502:physiology; D011446:Prospective Studies; D012307:Risk Factors; D012885:Skinfold Thickness; D013019:South Africa / Q000453:epidemiology; D015430:Weight Gain / Q000502:physiology