rss
Thorax 63:14-20 doi:10.1136/thx.2007.082784
  • Asthma

Body mass index and asthma severity in the National Asthma Survey

  1. B Taylor1,
  2. D Mannino2,
  3. C Brown3,
  4. D Crocker3,
  5. N Twum-Baah1,
  6. F Holguin1
  1. 1
    Emory University, Atlanta, Georgia, USA
  2. 2
    University of Kentucky, Lexington, Kentucky, USA
  3. 3
    Centers for Disease Control and Prevention, Atlanta, Georgia, USA
  1. Dr F Holguin, Clinical Research Center, Emory Crawford Long Hospital, 550 Peachtree St, Davis-Fischer Building, Room 2331, Atlanta, GA 30308, USA; fch5{at}cdc.gov
  • Received 13 April 2007
  • Accepted 5 July 2007

Abstract

Background: The association between obesity and asthma severity remains controversial and limited to small studies.

Methods: We determined the association of body mass index (BMI) and asthma severity in the National Asthma Survey. We included adults (age ⩾18 years) who self-reported symptoms of asthma in the past 5 years. A total of 3095 patients were divided into the following BMI categories: 1080 (35%) non-overweight (BMI <25), 993 (32%) overweight (BMI ⩾25 and <30) and 1022 (33%) obese (BMI ⩾30). Asthma severity measures included respiratory symptoms, healthcare utilisation, medication use, missed work days and the Global Initiative for Asthma (GINA) severity classification. Models were adjusted for: gender, race, age, education, income, employment status, smoking status, family history of asthma, state of residence and residence in a metropolitan statistical area.

Results: Compared with non-overweight subjects, obese subjects with asthma were more likely to report continuous symptoms (OR 1.66, 95% CI 1.09 to 2.54), miss more work days (OR 1.35, 95% CI 1.01 to 1.81), use short acting beta agonists (OR 1.36, 95% CI 1.06 to 1.75), use inhaled corticosteroids (OR 1.34, 95% CI 1.01 to 1.79) and use any controller medication according to GINA guidelines (OR 1.37, 95% CI 1.01 to 1.85). Also, obese respondents were less likely to be in asthma remission (OR 0.56, 95% CI 0.38 to 0.82) and were more likely to have severe persistent asthma (GINA IV) (OR 1.42, 95% CI 1.05 to 1.90).

Conclusions: In a large, diverse sample of adults with asthma, obesity was associated with measures of asthma severity after adjusting for potential confounders.

Footnotes

  • Funding: Supported by the CDC (Air Pollution Respiratory Health branch) and ORISE fellowship (Oakridge Institute for Science and Education). Research also supported by NIH/NCRR K12 RR017643.

  • Competing interests: None.