title: Comparison of childhood wheezing phenotypes in 2 birth cohorts: ALSPAC and PIAMA.
abstract: BACKGROUND
  Asthma has its origins in early childhood, but different patterns of childhood wheezing vary in their associations with subsequent asthma, atopy, and bronchial hyperresponsiveness (BHR). Novel wheezing phenotypes have been identified on the basis of analyses of longitudinal data from the Avon Longitudinal Study of Parents And Children (ALSPAC). It is unclear whether these phenotypes can be replicated in other birth cohorts.
  
  
  OBJECTIVE
  To compare wheezing phenotypes identified in the first 8 years of life in the ALSPAC study and the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study.
  
  
  METHODS
  We used longitudinal latent class analysis to identify phenotypes on the basis of repeated reports of wheezing from 0 to 8 years in 5760 children from the ALSPAC study and 2810 children from the PIAMA study. Phenotypes were compared between cohorts. Associations with asthma, atopy, BHR, and lung function were analyzed by using weighted regression analyses.
  
  
  RESULTS
  The model with the best fit to PIAMA data in the first 8 years of life was a 5-class model. Phenotypes identified in the PIAMA study had wheezing patterns that were similar to those previously reported in ALSPAC, adding further evidence to the existence of an intermediate-onset phenotype with onset of wheeze after 2 years of age. Associations with asthma, atopy, BHR, and lung function were remarkably similar in the 2 cohorts.
  
  
  CONCLUSIONS
  Wheezing phenotypes identified by using longitudinal latent class analysis were comparable in 2 large birth cohorts. Study of genetic and environmental factors associated with different phenotypes may help elucidate the origins of asthma.
authors.affiliation: Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Olga E
authors.initials: OE
authors.lastname: Savenije
authors.forename: Raquel
authors.initials: R
authors.lastname: Granell
authors.forename: Daan
authors.initials: D
authors.lastname: Caudri
authors.forename: Gerard H
authors.initials: GH
authors.lastname: Koppelman
authors.forename: Henriëtte A
authors.initials: HA
authors.lastname: Smit
authors.forename: Alet
authors.initials: A
authors.lastname: Wijga
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Sterne
authors.forename: Dirkje S
authors.initials: DS
authors.lastname: Postma
authors.forename: John
authors.initials: J
authors.lastname: Henderson
authors.forename: Marjan
authors.initials: M
authors.lastname: Kerkhof
mesh_terms: D017668:Age of Onset; D001249:Asthma / Q000145:classification / Q000209:etiology / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D008954:Models, Biological; D009426:Netherlands; D010641:Phenotype; D011247:Pregnancy; D012135:Respiratory Sounds / Q000145:classification / Q000503:physiopathology*; D006113:United Kingdom