title: Association between asthma and body mass index and socioeconomic status: A cross-sectional study on 849,659 adolescents.
abstract: OBJECTIVE
  Asthma is associated with body mass index (BMI), but its association with socioeconomic status (SES) is controversial. The combined effect of SES and BMI on asthma prevalence is undetermined.
  
  
  METHODS
  Seventeen-year-old pre-recruits to the Israeli Defense Forces underwent routine physical examinations. SES was determined according to established criteria based on place of residence. The study population was divided according to classic weight groups and three SES groups (low, medium and high). Univariable and multivariable logistic regression models were applied to assess odds ratios (OR) of BMI and SES groups for asthma prevalence. The combined effect of BMI and SES was also calculated.
  
  
  RESULTS
  The 849,659 subjects included 480,993 males (9.5% asthma prevalence) and 368,666 females (6.7% asthma prevalence). Increased BMI were associated with increased OR for asthma in females (1.44, 95% CI 1.36-1.52 for obese vs normal weight). Males had a J-shaped curve (OR 1.24 95% CI 1.2-1.29 for obese, 1.12, 95% CI 1.08-1.16 for underweight, both vs normal weight). OR adjusted to SES did not change significantly. All SES groups produced a linear curve (1.59 95% CI 1.53-1.66 for females and 1.79 95% CI 1.74-1.84 for males). Adjustment of SES to BMI produced no significant change in OR. When all groups were compared with the normal weight/lower SES group, the highest OR was for the obese/higher SES group (2.32 95% CI 2.05-2.64 for females and 1.99 95% CI 1.83-2.13 for males).
  
  
  CONCLUSIONS
  Both BMI and SES are co-independently associated with asthma in adolescent males and females.
authors.affiliation: Medical Corps, Israeli Defense Forces, Tel Hashomer, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Barak
authors.initials: B
authors.lastname: Gordon
authors.affiliation: Medical Corps, Israeli Defense Forces, Tel Hashomer, Israel.
authors.forename: Aviad
authors.initials: A
authors.lastname: Hassid
authors.affiliation: Pulmonology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Bar-Shai
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Estela
authors.initials: E
authors.lastname: Derazne
authors.affiliation: Medical Corps, Israeli Defense Forces, Tel Hashomer, Israel.
authors.forename: Dorit
authors.initials: D
authors.lastname: Tzur
authors.affiliation: Medical Corps, Israeli Defense Forces, Tel Hashomer, Israel.|Orthopedic Department, Chaim Sheba Medical Center, Tel Hashomer, Israel.
authors.forename: Oded
authors.initials: O
authors.lastname: Hershkovich
authors.affiliation: Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Arnon
authors.initials: A
authors.lastname: Afek
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D056865:Ideal Body Weight; D007557:Israel / Q000453:epidemiology; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D012737:Sex Factors; D012923:Social Class; D013851:Thinness / Q000453:epidemiology*
keywords: adolescent; asthma; body mass index; socioeconomic status