The effects of truncal adiposity in forced spirometry: Sex differences

•Some components of body fat measured by DXA negatively and significantly influence the spirometric results of healthy non-smoking individuals.•The influence is greater on FEV1 than on FVC, indicating that the accumulation of fat could affect more the contraction of the expiratory muscles.•In males, no significant differences between the influence of thoracic and abdominal fat on spirometry were found.•In females the influence of abdominal fat on spirometric results is clearly higher. The aim of the current paper is to establish the influence of truncal fat accumulation on the spirometric results of a group of healthy individuals. A cross-sectional study of 305 healthy, non-smoking adult subjects (144 males, 161 females) was conducted. Forced spirometry and dual-energy X-ray absorptiometry to quantify body fat were performed. Partial correlation and multiple linear regression analyses were performed. In females, abdominal fat was negatively correlated with forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). In males, thoracic fat was negatively correlated with respiratory variables, as was abdominal fat. In the multiple linear regression, FEV1 was the spirometric parameter that showed higher R2 values in both sexes. Truncal fat had a greater influence on FEV1 than on FVC. In males, no significant differences between the influence of thoracic and abdominal fat on spirometric results were found, and total body fat was shown to have more influence than regional. In females, the influence of abdominal fat was higher.