Obesity and lung function among healthy employees of a regional urban medical college in odisha, India

Abstract

Obesity associated restrictive lung capacity is poorly understood, notably in an otherwise healthy population.  To evaluate this relationship, we recruited non-smokers without any pulmonary disorders & examined their body mass index (BMI) and standard pulmonary tests. Following consent and eligibility determination, 81 healthy non-smokers from 354 employees at a regional medical college were considered. Overall, BMI was inversely correlated with MVV15 (r=-0.24, p=0.03). Analysis of mean Maximum Voluntary Ventilation (MVV15) stratified by BMI categories showed an inverse gradient MVV15 by ascending obesity categories (normal-overweight-obesity). In one multiple regression analyses, after adjusting for age, gender, FEV1/FVC ratio, overall BMI contributed to a quarter of a point lowering of MVV15 (beta=-0.248, t=2.36, p=0.02), with the model explaining 26% of variance (R²=25.5). In a separate equation with same covariates, obese participants (BMI>=30) contributed almost a 4-point reduction in MVV15 (beta=3.91, t=2.73, p=0.007) with the latter model explaining 28% of variance (R²=27.6%) in MVV15. Obesity in healthy individuals may produce restrictive pulmonary function due to differential distribution of adipose tissue in the chest and abdomen, which needs further investigation.