title: Factors related to allergic sensitization to aeroallergens in a cross-sectional study in adults: The Copenhagen Allergy Study.
abstract: BACKGROUND
  The factors underlying recent increases in the prevalence of respiratory allergy are largely unknown.
  
  
  OBJECTIVE
  To assess the association between allergic sensitization and several lifestyle/environmental factors.
  
  
  METHODS
  A cross-sectional population-based study of 15-69-year-olds in Copenhagen was carried out in 1990. The participation rate was 77.5% (1112/1435). Different lifestyle/environmental factors (explanatory variables) were defined based on questionnaire data. Dependent (outcome) variables were skin prick test (SPT) positivity or specific IgE positivity to common aeroallergens. Explanatory variables associated with outcome in univariate analysis (P < 0.25) were selected for multivariate analysis. Subsequently, a final model for each dependent variable was obtained by stepwise regression analysis (cut-off for entry/removal of variables: P < 0.1).
  
  
  RESULTS
  Male sex, young age, low number of siblings, a positive family history of hay fever and never smoking, were independently associated with both SPT positivity and specific IgE positivity. Furthermore, SPT positivity was positively associated with alcohol consumption (dose-response relationship only), and negatively associated with previous keeping of a dog in the household. The association between alcohol consumption and SPT positivity was mainly due to the consumption of wine and remained after adjustment for educational level. Specific IgE positivity was furthermore associated with body mass index with no apparent dose-response relationship.
  
  
  CONCLUSIONS
  Being male, young age, a positive family history of hayfever, low number of siblings and never smoking, were independently associated with allergic sensitization. In addition, the results indicated a possible relationship of alcohol consumption, body mass index and previous keeping of a dog in the household to allergic sensitization. There is a need for prospective studies of risk factors for respiratory allergy.
authors.affiliation: Centre for Preventive Medicine, Department of Internal Medicine M, Glostrup Hospital, Glostrup, Denmark. alli@glostruphosp.dk
authors.forename: A
authors.initials: A
authors.lastname: Linneberg
authors.forename: N H
authors.initials: NH
authors.lastname: Nielsen
authors.forename: F
authors.initials: F
authors.lastname: Madsen
authors.forename: L
authors.initials: L
authors.lastname: Frølund
authors.forename: A
authors.initials: A
authors.lastname: Dirksen
authors.forename: T
authors.initials: T
authors.lastname: Jørgensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000428:Alcohol Drinking / Q000276:immunology; D000485:Allergens / Q000276:immunology*; D000704:Analysis of Variance; D000818:Animals; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D004285:Dogs; D004777:Environment; D005260:Female; D006801:Humans; D007114:Immunization; D007073:Immunoglobulin E / Q000276:immunology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012130:Respiratory Hypersensitivity / Q000209:etiology* / Q000276:immunology*; D012307:Risk Factors; D012737:Sex Factors; D012882:Skin Tests; D012907:Smoking / Q000276:immunology
chemical_list: D000485:Allergens; D007073:Immunoglobulin E