Body Mass Index and Asthma in Virginia
PEGGIE A. SMITH
Advisor: M. Njeri Jackson, Ph.D.
Preceptor: Gerges Seifen, M.D., M.P.H.
Background: Asthma is a chronic respiratory disease that affects both children and adults. Asthma has a substantial impact on health, quality of life, and the economy. An increase in the prevalence of asthma over the past twenty years has been reported in many developed countries. In the United States, over 30 million people had been diagnosed with asthma in their lifetime. Currently, there is no cure for asthma, but efforts are being made to identify its predictors.
Objectives: This study was conducted to examine the association between body mass index (BMI) and asthma in the adult population of Virginia and to determine if a relationship exists after adjusting for confounders.
Methods: A random-digit cross-sectional telephone survey of adults aged 18 years and older residing in Virginia participating in the Virginia Behavioral Risk Factor Surveillance Survey (BRFSS) 2002 was conducted. Asthma was defined as having ever been diagnosed by a physician as having asthma. Body mass index was categorized into overweight (25 kg/m 2 < BMI<30 kg/m 2) and obese (BMI >30 kg/m 2). Factors examined for confounding included race, gender, age, income, education, employment, health insurance coverage, physical activity, diet, and smoking. Prevalence, crude and adjusted odds ratio, and their 95% confidence intervals were calculated. Logistic regression was used to estimate the risk of asthma predicted by BMI, demographic, social, and lifestyle factors.
Results: Of the 4, 392 participants analyzed, 12.5% were found to have asthma. The prevalence of asthma in those who were overweight was 11.3% (95% CI 9.7-13.0). The prevalence of asthma in those who were obese was 15.2% (95% CI 13.1-17.6). Those with asthma were significantly more likely to be female, younger age, have lower incomes, be unemployed, obese, and have no physical activity. After adjusting for confounders, those that were overweight had an odds ratio of 1.5(95% CI 1.1-1.9) for diagnosed asthma. Individuals that were obese had an odds ratio of 1.4 (95% CI 1.0-1.8).
Conclusion: The results of this study support the hypothesis that higher body mass indexes are associated with an increased risk of asthma prevalence.
