Association of General and Central Obesity and Atopic and Nonatopic Asthma in US Adults

Abstract

Objective. To examine the association of body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) with the prevalence of asthma by atopic status and sex using nationally representative data in the US. Methods. The National Health and Nutrition Examination Survey 2005–2006 data were analyzed using areas under the receiver operating characteristic (ROC) curves (AUCs) and multivariate logistic regression models. Results. Women had higher AUCs (0.59–0.64) than men (0.50–0.58) across anthropometric indices and asthma outcomes. After controlling for sociodemographic characteristics and smoking status, only WHtR was positively associated with atopic asthma in both sexes (odds ratio per 1 SD [95% confidence interval]: men, 1.018 [1.004, 1.032], p = .01; women, 1.018 [1.006, 1.030], p = .003), and the associations persisted after further adjustment of BMI. Only in women was nonatopic asthma significantly associated with every 1 SD increase of BMI (odds ratio [95% confidence interval]: 1.018 [1.006, 1.030], p = .003), WC (1.018 [1.006, 1.030], p = .004), and WHtR (1.016 [1.004, 1.028], p = .008). Conclusions. Using US national data, this study adds to the emerging evidence suggesting two possible distinct phenotypes: (1) obese men and women with atopic asthma and (2) obese women with nonatopic asthma. The mechanistic and therapeutic implications of these findings warrant further investigation.

• asthma
• atopy
• body mass index
• obesity
• waist circumference
• waist-to-height ratio