title: Reduced infant lung function, active smoking, and wheeze in 18-year-old individuals.
abstract: IMPORTANCE This is the first study to link reduced lung function in early life, before the development of symptoms, to wheeze in 18-year-olds. Additionally, the study gives insight into factors other than reduced lung function that are also associated with persistent wheeze in young adults.
  
  
  OBJECTIVE
  To test the hypothesis that reduced lung function in early life is associated with increased risk for persistent wheeze at age 18 years.
  
  
  METHODS
  Birth cohort study.
  
  
  METHODS
  Perth, Western Australia.
  
  
  METHODS
  Individuals followed up from age 1 month to 18 years.
  
  
  METHODS
  Maximal flow at functional residual capacity (V'maxFRC) was measured in 1-month-old infants who were followed up at ages 6, 12, and 18 years. Based on reported symptoms, individuals were categorized as having remittent wheeze, later-onset wheeze, persistent wheeze, and no wheeze. Smoking status was noted at age 18 years.
  
  
  RESULTS
  Of the 253 individuals originally recruited, 150 were followed up at age 18 years; 37 of the 150 had recent wheeze. Compared with the no-wheeze group (n = 96), persistent wheeze (n = 13) was independently associated with reduced percentage of predicted V'maxFRC (mean reduction, 43%; 95% CI, 13-74). Compared with the no-wheeze group, persistent wheeze was also associated with atopy in infancy (odds ratio = 7.1; 95% CI, 1.5-34.5), maternal asthma (odds ratio = 6.8; 95% CI, 1.4-32.3), and active smoking (odds ratio = 4.8; 95% CI, 1.0-21.3). When only wheeze at age 18 years was considered, reduced percentage of predicted V'maxFRC was associated with wheeze at age 18 years only among current smokers (P = .04).
  
  
  CONCLUSIONS
  Wheeze persisting from ages 6 to 18 years is associated with multiple factors, including reduced infant lung function, infant-onset atopy, maternal asthma, and active smoking. Wheeze at age 18 years (regardless of previous wheeze status) is associated with active smoking, but only among those with reduced lung function in infancy. These findings give unique insight into the cause of obstructive airways disease in 18-year-olds, and follow-up of this cohort might be expected to further extend our understanding.
authors: Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.
authors: David
authors: D
authors: Mullane
authors: Steve W
authors: SW
authors: Turner
authors: Des W
authors: DW
authors: Cox
authors: Des
authors: D
authors: Cox
authors: Jack
authors: J
authors: Goldblatt
authors: Lou I
authors: LI
authors: Landau
authors: Peter N
authors: PN
authors: le Souëf
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D005652:Functional Residual Capacity; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008168:Lung / Q000502:physiology*; D008297:Male; D012129:Respiratory Function Tests; D012135:Respiratory Sounds / Q000503:physiopathology*; D012907:Smoking / Q000503:physiopathology*; D013147:Spirometry