title: Lung function trajectories from birth through puberty reflect asthma phenotypes with allergic comorbidity.
abstract: BACKGROUND
  Childhood asthma phenotypes reflecting underlying developmental mechanisms are sought, with little information on asthma phenotypes based on allergic comorbidities.
  
  
  OBJECTIVE
  We asked whether lung function trajectories from birth to 16 years were associated with asthma phenotypes with comorbid allergic rhinitis and atopic dermatitis.
  
  
  METHODS
  Lung function (given as z scores) was measured at birth in 329 subjects in the "Environment and Childhood Asthma" birth cohort study in Oslo by using tidal flow volume loops, and at 10 and 16 years by using spirometry. Asthma phenotypes were classified on the basis of recurrent bronchial obstruction at 0 to 2 years, and asthma from the 2- to 10-year and 10- to 16-year intervals, and by combining asthma, atopic dermatitis, and/or allergic rhinitis from 10 to 16 years, stratifying for allergic sensitization. The reference group included 231 subjects without recurrent bronchial obstruction or asthma.
  
  
  RESULTS
  Lung function trajectories differed significantly for asthma comorbidity phenotypes for FEV1, forced expiratory flow at 25% to 75% of forced vital capacity, and FEV1/forced vital capacity (all P < .0001). Significant lung function impairment was observed from birth through 16 years among subjects with asthma, atopic dermatitis, and allergic rhinitis. Lung function trajectories in subjects with asthma at 10 to 16 years or asthma in remission differed significantly for all 3 spirometric values compared with the trajectories in those who never had asthma (P < .0001), but not between asthma groups. Allergic sensitization was not significantly associated with asthma phenotype lung function trajectories.
  
  
  CONCLUSIONS
  The trajectory consisting of impaired lung function from birth throughout childhood in children with asthma, atopic dermatitis, and allergic rhinitis appears less likely to be driven by allergic sensitization, and may imply disease onset in utero, with clinical presentation later in childhood.
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway. Electronic address: k.c.l.carlsen@medisin.uio.no.
authors.forename: Karin C
authors.initials: KC
authors.lastname: Lødrup Carlsen
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Petter
authors.initials: P
authors.lastname: Mowinckel
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Vegard
authors.initials: V
authors.lastname: Hovland
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Geir
authors.initials: G
authors.lastname: Håland
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Amund
authors.initials: A
authors.lastname: Riiser
authors.affiliation: Department of Paediatrics, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: Kai-Håkon
authors.initials: KH
authors.lastname: Carlsen
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D003876:Dermatitis, Atopic / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008168:Lung / Q000276:immunology / Q000378:metabolism*; D008297:Male; D009664:Norway; D010641:Phenotype; D011627:Puberty; D012129:Respiratory Function Tests / Q000706:statistics & numerical data; D065631:Rhinitis, Allergic / Q000453:epidemiology*
keywords: Lung function trajectory; allergic disease; asthma; birth cohort; child