THE EFFECT OF BODY-FAT DISTRIBUTION ON PULMONARY-FUNCTION TESTS

Although the influence of obesity on pulmonary function tests has been examined, the role of body fat distribution has received limited atte ntion. Pulmonary studies of patients severely affected by upper body o besity suggest they have more severely compromised lung volumes than o bese patients with lower body obesity, We examined 42 healthy but norm al or mildly obese men to determine if body fat distribution influence s pulmonary function tests. Multiple measures of adiposity showed a si gnificant inverse relationship with both spirometry and static lung vo lumes, However, the biceps skinfold thickness had the strongest invers e relationship with total lung capacity (TLC) compared to other anthro pometric measures. The waist-to-hip ratio (WHR) demonstrated a signifi cant inverse relationship with static lung volumes only when controlli ng for cigarette smoking. However, comparing pulmonary function tests between patients with a WHR less than 0.950 (lower body fat distributi on) and subjects with a WHR of 0.950 or greater (upper body fat distri bution) revealed that FVC, FEV(1), and TLC were significantly lower in the patients with upper body fat distribution, Stepwise multiple regr ession analysis was done using all anthropometric variables and age wh ich generated predictive equations that included the biceps skinfold t hickness for residual volume (RV) and TLC. This suggests that upper bo dy fat distribution may be associated with a modest impairment of lung volumes in normal and mildly obese men. Until the findings of this st udy can be applied to a larger, ethnically and anthropometrically dive rse population, and to women, we believe caution is warranted when sta ndard equations are used to predict pulmonary function tests in an ant hropometrically diverse population.