title: Adult obesity, farm childhood, and their effect on allergic sensitization.
abstract: BACKGROUND
  Obesity as well as a reduced microbial exposure, 2 markers of Western lifestyle, might be associated with an increased risk of allergic sensitization.
  
  
  OBJECTIVE
  We aimed to analyze the interplay of these markers of Western lifestyle on allergic sensitization.
  
  
  METHODS
  A questionnaire survey was completed by rural adults (18-45 years). Clinical assessments included those of sensitization (specific IgE) against inhalant allergens and body mass index (BMI). Subjects were grouped on the basis of their recent BMI (obesity: BMI > or =30 kg/m2) and whether they had regular farm contact during the first 3 years of life (farm subjects). Nonobese nonfarm subjects served as the reference group. Overall, 1861 subjects were included in the analyses.
  
  
  RESULTS
  Compared with nonobese nonfarm subjects, nonobese farm subjects showed a decreased odds ratio for sensitization (odds ratio, 0.6; 95% CI, 0.5-0.8). This decrease was not observed in obese subjects (obese nonfarm subjects: 1.2, 0.8-1.9; obese farm subjects: 1.0, 0.6-1.6). Associations were similar for symptoms of allergic rhinitis.
  
  
  CONCLUSIONS
  Obesity, as a risk factor for respiratory allergies per se, might diminish or even cancel the protective effect of a farm childhood.
  
  
  CONCLUSIONS
  The high prevalence of respiratory allergies in inner-city societies despite lower levels of hygiene might be explained by obesity.
authors.affiliation: Institute for Occupational and Environmental Medicine, Unit for Occupational and Environmental Epidemiology & Net Teaching, Ludwig-Maximilians-University of Munich, Germany. Katja.Radon@med.uni-muenchen.de
authors.forename: Katja
authors.initials: K
authors.lastname: Radon
authors.forename: Anja
authors.initials: A
authors.lastname: Schulze
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000276:immunology; D000818:Animals; D000829:Animals, Domestic / Q000276:immunology; D003430:Cross-Sectional Studies; D004781:Environmental Exposure; D005858:Germany / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D007114:Immunization; D008019:Life Style; D008875:Middle Aged; D009765:Obesity / Q000276:immunology*; D015995:Prevalence; D012221:Rhinitis, Allergic, Perennial / Q000453:epidemiology* / Q000517:prevention & control; D012307:Risk Factors; D012424:Rural Population; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens