title: Relationship between childhood body mass index and young adult asthma.
abstract: BACKGROUND
  The relationship between obesity and asthma is an area of debate.
  
  
  OBJECTIVE
  To investigate the association of elevated body mass index (BMI) at a young age and young adult asthma.
  
  
  METHODS
  BMI, questionnaires, and serologic tests results were analyzed in participants of a predominantly white, middle-class, population-based birth cohort from Detroit, Michigan at 6 to 8 and 18 years of age. Asthma diagnosis was based on medical record data. Allergen specific IgE was analyzed using UniCAP, with atopy defined as 1 or more allergen specific IgE levels of 0.35 kU/L or higher. Overweight was defined as a BMI in 85th percentile or higher.
  
  
  RESULTS
  A total of 10.6% of overweight males at 6 to 8 years of age had current asthma at 18 to 20 years of age compared with 3.2% of males who were normal or underweight (relative risk [RR], 3.3; 95% confidence interval [CI], 1.0-11.0; P=.048). A total of 19.6% of females who were overweight at 6 to 8 years of age had asthma compared with 10.3% of females who were normal or underweight (RR, 1.9; 95% CI, 0.9-3.9; P=.09). After adjustment for atopy at 6 to 8 years of age, overweight males had an adjusted RR of 4.7 (95% CI, 1.4-16.2; P=.01), and overweight females had an adjusted RR of 1.7 (95% CI, 0.8-3.3; P=.15). Change in BMI between 6 to 8 years of age and 18 to 20 years of age was also examined. Patients with persistently elevated BMI exhibited increased risk of asthma as young adults (RR, 2.4; 95% CI, 1.2-4.7) but not with an increasing BMI (RR, 0.8; 95% CI, 0.3-2.2) or a decreasing BMI (RR, 0.8; 95% CI, 0.3-2.2).
  
  
  CONCLUSIONS
  Overweight males 6 to 8 years of age have increased risk of asthma as young adults. Being overweight remains a predictor of asthma after adjustment for early atopy. A similar but not statistically significant trend was also seen among overweight females. Overweight body habitus throughout childhood is a risk factor for young adult asthma.
authors.affiliation: Division of Allergy and Clinical Immunology, Department of Internal Medicine, Henry Ford Hospital, Detroit, Michigan, USA. minto.porter@essentiahealth.org
authors.forename: Minto
authors.initials: M
authors.lastname: Porter
authors.forename: Ganesa
authors.initials: G
authors.lastname: Wegienka
authors.forename: Suzanne
authors.initials: S
authors.lastname: Havstad
authors.forename: Christian G
authors.initials: CG
authors.lastname: Nageotte
authors.forename: Christine Cole
authors.initials: CC
authors.lastname: Johnson
authors.forename: Dennis R
authors.initials: DR
authors.lastname: Ownby
authors.forename: Edward M
authors.initials: EM
authors.lastname: Zoratti
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D015992:Body Mass Index; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008824:Michigan / Q000453:epidemiology; D009765:Obesity / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D012307:Risk Factors; D012698:Serologic Tests / Q000379:methods; D012923:Social Class; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D007073:Immunoglobulin E