Association of Body Mass Index (BMI) with Lung Function Parameters in Non-asthmatics Identified by Spirometric Protocols

Association between obesity and asthma has been reported widely, with disparity between males and females. Epidemiological data which indicate that obesity precedes development of asthma and increases the prevalence and incidence of asthma, raises the possibility of a causal association. To find out the association, including gender differences, between Body Mass Index (BMI) and lung functions in non-asthmatics identified by spirometric protocols. A retrospective analysis was conducted of the spirometry results obtained between October 2012 and March 2013 for six months. Participants were referred by a variety of medical specialties to the pulmonary function laboratory in Physiology department, R.G. Kar Medical College, Kolkata, India of the 590 test results recorded in the study database 424 non-asthmatic subjects were reviewed. Significant differences in the spirometric parameters, measured as a percentage of predicted were evident between male and female. Among obese subjects significant correlation is found between BMI and pulmonary function values, FEV1(r = -0.531, p=0.009); FEF25-75% (r= -0.653, p=0.001); FEV1/FVC (r= - 0.603, p=0.002). Significant association was found between BMI and lung function in obese female but not in obese male. Association was found between indices of spirometry and BMI in non-asthmatic obese group along with a gender disparity.