Association of Body Composition with the Development of Airway Hyper-Responsiveness

Abstract

Background: The rising prevalence of asthma may be associated with the rising prevalence of obesity in developed nations. There are several studies showing that obesity increases the risk of asthma in adults. We investigated the association of each body composition scale and bronchial hyper-responsiveness. Methods: This study involved a retrospective review of the existing records for 279 subjects with respiratory symptoms, who underwent a pulmonary function test, a methacholine challenge test and a body composition test between May 2007 and June 2009. Results: Of the 279 subjects, 179 (64%) were female. There was a statistically significant difference in fat free mass and in fat free mass index between the normal bronchial responsiveness group and bronchial hyper-responsiveness group (p=0.036; p=0.000). There was no significant differences in body mass index, in fat mass and fat free mass index in the normal bronchial responsiveness group and bronchial hyper-responsiveness group in males. However in females, body mass index and fat free mass index were increased in the bronchial hyper-responsiveness group (p=0.044; p=0.000). Total body water (kg), fat free mass (kg) and soft lean mass (kg) were significantly different between the normal bronchial responsiveness group and bronchial hyper-responsiveness group (p=0.002; p=0.000; p=0.000). Conclusion: This study showed significant differences in fat free mass and in fat free mass index between the normal bronchial responsiveness group and the bronchial hyper-responsiveness group. In females, BMI, soft lean mass, and total body water showed significant differences between the normal bronchial responsiveness group and the bronchial hyper-responsiveness group. We concluded that bronchial hyper-responsiveness was associated with not only body mass index but also fat free mass index in female bronchial asthma.