title: Body mass index trajectory classes and incident asthma in childhood: results from 8 European Birth Cohorts--a Global Allergy and Asthma European Network initiative.
abstract: BACKGROUND
  The causal link between body mass index (BMI) or obesity and asthma in children is still being debated. Analyses of large longitudinal studies with a sufficient number of incident cases and in which the time-dependent processes of both excess weight and asthma development can be validly analyzed are lacking.
  
  
  OBJECTIVE
  We sought to investigate whether the course of BMI predicts incident asthma in childhood.
  
  
  METHODS
  Data from 12,050 subjects of 8 European birth cohorts on asthma and allergies were combined. BMI and doctor-diagnosed asthma were modeled during the first 6 years of life with latent growth mixture modeling and discrete time hazard models. Subpopulations of children were identified with similar standardized BMI trajectories according to age- and sex-specific "World Health Organization (WHO) child growth standards" and "WHO growth standards for school aged children and adolescents" for children up to age 5 years and older than 5 years, respectively (BMI-SDS). These types of growth profiles were analyzed as predictors for incident asthma.
  
  
  RESULTS
  Children with a rapid BMI-SDS gain in the first 2 years of life had a higher risk for incident asthma up to age 6 years than children with a less pronounced weight gain slope in early childhood. The hazard ratio was 1.3 (95% CI, 1.1-1.5) after adjustment for birth weight, weight-for-length at birth, gestational age, sex, maternal smoking in pregnancy, breast-feeding, and family history of asthma or allergies. A rapid BMI gain at 2 to 6 years of age in addition to rapid gain in the first 2 years of life did not significantly enhance the risk of asthma.
  
  
  CONCLUSIONS
  Rapid growth in BMI during the first 2 years of life increases the risk of asthma up to age 6 years.
authors: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology I, Neuherberg, Germany. Peter.Rzehak@med.uni-muenchen.de
authors: Peter
authors: P
authors: Rzehak
authors: Alet H
authors: AH
authors: Wijga
authors: Thomas
authors: T
authors: Keil
authors: Esben
authors: E
authors: Eller
authors: Carsten
authors: C
authors: Bindslev-Jensen
authors: Henriette A
authors: HA
authors: Smit
authors: Joost
authors: J
authors: Weyler
authors: Sandra
authors: S
authors: Dom
authors: Jordi
authors: J
authors: Sunyer
authors: Michelle
authors: M
authors: Mendez
authors: Maties
authors: M
authors: Torrent
authors: Oriol
authors: O
authors: Vall
authors: Carl-Peter
authors: CP
authors: Bauer
authors: Dietrich
authors: D
authors: Berdel
authors: Beate
authors: B
authors: Schaaf
authors: Chih-Mei
authors: CM
authors: Chen
authors: Anna
authors: A
authors: Bergström
authors: Maria P
authors: MP
authors: Fantini
authors: Monique
authors: M
authors: Mommers
authors: Ulrich
authors: U
authors: Wahn
authors: Susanne
authors: S
authors: Lau
authors: Joachim
authors: J
authors: Heinrich
mesh_terms: D001249:Asthma / Q000150:complications* / Q000453:epidemiology*; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009765:Obesity / Q000150:complications*; D012307:Risk Factors