Waist circumference does not correlate with functional lung capacity in moderate and severe chronic obstructive pulmonary disease.

ABSTRACT

Waist circumference is a good predictor of the risk of heart diseases, but data on the relationship between waist circumference and pulmonary diseases are sparse. The aim of this study was to investigate its influence on pulmonary function regarding exercise capacity in moderate and severe chronic obstructive pulmonary disease (COPD), according to Global Initiative for Lung Diseases (GOLD) stages. During 2009, a total of 70 COPD patients aged 33 to 80 years were stratified into GOLD 2 and GOLD 3 stages. Diagnostic separation between COPD severity groups was made upon percentage of predicted forced expiratory volume in 1 second. Anthropometric measures, lung function testing and prognostic scoring systems were assessed. Logistic regression analysis was used to make comparisons while taking into account the possible confounding factors. Waist circumference did not show substantial variations between GOLD 2 and GOLD 3 stages (p > 0.5). There was a weak positive correlation between waist circumference and percent of predicted 6-minute walking distance (r = 0.237; p = 0.001). Another parameter, suprailiac skinfold, was significantly different between GOLD 2 and GOLD 3 stages (19.41 vs. 15.32 mm; p = 0.047). Although waist circumference is a meaningful marker of abdominal obesity, which influences pulmonary function, we failed to prove its importance in correlation with functional lung capacity in a selected COPD population. However, suprailiac skinfold deserves greater attention and further evaluation.