title: Obesity is associated with increased risk of allergy in Vietnamese adolescents.
abstract: BACKGROUND
  The prevalence of allergic diseases has remarkably increased in the last decades in tandem with the number of obese individuals. Results of studies on obesity and allergic diseases are controversial, and most of them are related to asthma and asthma-like symptoms.
  
  
  OBJECTIVE
  In our study, we evaluated the association of several obesity indices and the prevalence of allergic diseases, including bronchial asthma, allergic rhino-conjunctivitis, atopic dermatitis and food allergy.
  
  
  METHODS
  Cross-sectional study.
  
  
  RESULTS
  From a total of 1185 adolescents (49.3% boys) aged 12 to 17 y old, 19.3% reported a physician-diagnosed allergic disease, and 35.3% reported undiagnosed allergic symptoms. Logistic regression analysis revealed a higher risk of allergy in children of middle (OR = 2.02, CI: 1.12-3.64) and high (OR = 2.40, CI: 1.25-4.61) compared to low socioeconomic status, in subjects reporting industrial emissions in the neighborhood (OR = 2.19, CI: 1.40-3.41), and in adolescents with parental history of allergy (OR = 1.92, CI: 1.26-2.92). Body mass index (BMI) and percentage of body fat (%BF) were significantly related to allergy (OR = 1.16, CI: 1.01-1.34 for BMI; OR = 1.03, CI: 1.01-1.06 for %BF). After controlling for socioeconomic status, industrial emissions and parental history of allergy, only %BF remained statistically significant (OR = 1.03, CI: 1.01-1.06). Food allergy was not related to obesity in our study population, and when adolescents with food allergy were excluded from the analysis, the odds of having allergy increased 28% with each increase in SD of BMI (OR = 1.28, CI: 1.05-1.57) and 5% for each unit increase in the percentage of body fat (OR = 1.05, CI: 1.01-1.08).
  
  
  CONCLUSIONS
  In conclusion, being overweight was associated with an increased risk of allergy in our study population. Our results point towards an association between being overweight and rhino-conjunctivitis, but not food allergy. No association was observed with other allergic diseases.
authors.affiliation: Department of Food Science and Nutrition, Faculty of Human Life and Environment, Nara Women's University, Nara City, Japan.
authors.forename: A V
authors.initials: AV
authors.lastname: Irei
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: Duc Son N T
authors.initials: DS
authors.lastname: Le
authors.forename: P T N
authors.initials: PT
authors.lastname: Ha
authors.forename: N T K
authors.initials: NT
authors.lastname: Hung
authors.forename: D
authors.initials: D
authors.lastname: Kunii
authors.forename: T
authors.initials: T
authors.lastname: Sakai
authors.forename: T
authors.initials: T
authors.lastname: Matoba
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D002648:Child; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology*; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D016017:Odds Ratio; D010290:Parents; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D012923:Social Class; D011795:Surveys and Questionnaires; D014744:Vietnam / Q000453:epidemiology