Central Obesity and Asthma Outcomes in Adults Diagnosed with Asthma

Abstract

Objective. The potential role of central obesity in asthma outcomes has been examined in a few studies. The aim of this study was to examine the relationship between central obesity and asthma outcomes in a group of Iranian asthma patients. Methods. One hundred and forty-two outpatients with asthma were studied. Central obesity was defined according to National Institute of Health (NIH) and Asian waist circumference (WC) and waist-to-hip ratio (WHR) cut-offs. Asthma outcomes including asthma control, pulmonary function, and morbidity were evaluated. The association between central obesity and asthma outcomes was studied by linear and logistic regression analyses. Results. Linear regression analysis showed a significant association of WHR-based central obesity with forced expiratory volume in 1 s (FEV1) (β = −9.04; p-value = .044) and forced vital capacity (FVC) (β = −10.52; p-value = .012). Logistic regression analysis showed a significant increased risk of asthma attacks in 3 months with Asian WC-based central obesity [odds ratio (OR) = 6.31, 95% confidence interval (CI): 1.16–34.41]; emergency room (ER) visits with NIH WC-based (OR = 5.15, 95% CI: 1.36–19.55) and Asian WC-based (OR = 18.72, 95% CI: 1.92–182.63) central obesity; and hospitalization in 1 year with NIH WC-based (OR = 5.28, 95% CI: 1.28–21.84) and Asian WC-based (OR = 12.39, 95% CI: 1.29–119.53) central obesity. Conclusions. Our study shows that the Asian WC-based central obesity is a better predictor of asthma morbidity. The results of this study emphasize, when studying the relationship between asthma control and obesity, the importance of selecting the proper definitions for asthma control or central obesity and appropriate cutpoints. Further study in this field using other asthma control and quality of life questionnaires is warranted.