title: Postnatal growth velocity and overweight in early adolescents: a comparison of rural and urban African boys and girls.
abstract: OBJECTIVE
  To compare growth velocity of two African child cohorts and examine the relationship between postnatal growth velocity in infancy/early childhood and the risk of overweight/stunting in early adolescence.
  
  
  METHODS
  The study used data from two child cohorts from urban (Birth to Twenty Cohort, South Africa) and rural (Lungwena Child Survival Study, Malawi) African settings. Mixed effect modelling was used to derive growth and peak growth velocities. T-tests were used to compare growth parameters and velocities between the two cohorts. Linear and logistic regression models were used to determine the relationship between growth velocity and early adolescent (ages 9-11 years) body mass index and odds of being overweight.
  
  
  RESULTS
  Children in the BH cohort were significantly taller and heavier than those in the Lungwena cohort, and exhibited faster weight and height growth velocity especially in the first year of life (P < 0.05). No significant association was shown between baseline weight (αw ) and overweight in early adolescence (OR = 1.25, CI = 0.67, 2.34). The weight growth velocity parameter βw was highly associated with odds of being overweight. Association between overweight in adolescence and weight velocity was stronger in infancy than in early childhood (OR at 3 months = 4.80, CI = 2.49, 9.26; OR at 5 years = 2.39, CI = 1.65, 3.47).
  
  
  CONCLUSIONS
  High weight and height growth velocity in infancy, independent of size at birth, is highly associated with overweight in early adolescence. However, the long term effects of rapid growth in infancy may be dependent on a particular population's socio-economic status and level of urbanization.
authors.affiliation: Wits/MRC Developmental Pathways for Health Research Unit, Department of Pediatrics, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: E D
authors.initials: ED
authors.lastname: Chirwa
authors.forename: P
authors.initials: P
authors.lastname: Griffiths
authors.forename: K
authors.initials: K
authors.lastname: Maleta
authors.forename: P
authors.initials: P
authors.lastname: Ashorn
authors.forename: J M
authors.initials: JM
authors.lastname: Pettifor
authors.forename: S A
authors.initials: SA
authors.lastname: Norris
mesh_terms: D000293:Adolescent; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D050177:Overweight / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D012044:Regression Analysis; D012306:Risk; D012424:Rural Population; D012923:Social Class; D013019:South Africa / Q000453:epidemiology; D014505:Urban Population