title: Sex differences in factors associated with childhood- and adolescent-onset wheeze.
abstract: BACKGROUND
  Factors predicting the development of wheeze may differ between sexes and between childhood and adolescence.
  
  
  METHODS
  A New Zealand birth cohort of 1,037 children was followed to age 26. For this analysis, those reporting recurrent wheezing at two or more assessments were classified as "wheezers." We examined risk factors for development of wheeze before age 10 (childhood) and subsequently (adolescent-onset) for males and for females separately using Cox regression modeling.
  
  
  RESULTS
  Males more often developed childhood wheeze (p = 0.002) and females adolescent-onset wheeze (p < 0.001). Maternal atopy (asthma or hay fever) was a risk factor for childhood wheeze in both sexes (hazard ratio [HR], 1.48, p < 0.05 for males; HR, 2.37, p < 0.001 for females). Paternal atopy also influenced childhood wheeze, significantly for males (HR, 1.72; p = 0.01), and similarly but not significantly for females (HR, 1.70; p = 0.08). For adolescent-onset wheeze, neither maternal (HR, 1.41; p = 0.19) nor paternal history (HR, 0.73; p = 0.42) was a risk factor in males, but maternal history (HR, 2.08; p < 0.01) was a significant risk factor for females. When both age ranges were combined, providing greater power for analysis, paternal history was a stronger risk factor for wheeze in females (HR, 1.62; p = 0.02) than in males (HR, 1.35; p = 0.12).
  
  
  CONCLUSIONS
  The influence of parental atopy on the development for wheeze differs between males and females and between childhood- and adolescent-onset wheeze.
authors.affiliation: Firestone Institute for Respiratory Health, St. Joseph's Healthcare, 50 Charlton Avenue East, Hamilton, Ontario L8N 4A6, Canada.
authors.forename: Piush J
authors.initials: PJ
authors.lastname: Mandhane
authors.forename: Justina M
authors.initials: JM
authors.lastname: Greene
authors.forename: Jan O
authors.initials: JO
authors.lastname: Cowan
authors.forename: D Robin
authors.initials: DR
authors.lastname: Taylor
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Sears
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000704:Analysis of Variance; D001249:Asthma / Q000150:complications / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D016016:Proportional Hazards Models; D012135:Respiratory Sounds / Q000209:etiology*; D012307:Risk Factors; D012737:Sex Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires