Gender modifies the effect of body mass index on lung function decline in mild-to-moderate COPD patients: a pooled analysis

Abstract Background Low body weight is associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). However, it is not known whether gender modifies this relationship. Methods We pooled data of 8686 COPD patients from 7 studies with a median length of 36-months of follow up. Using a longitudinal natural cubic spline regression model, we examined the dose–response relationship between body mass index (BMI) and the rate of decline in forced expiratory volume in one second (FEV1) in patients with GOLD 1 and 2 disease, stratified by gender and adjusted for age, smoking status, and cohort effects. Results There was an inverse linear relationship between BMI and the rate of FEV1 decline in GOLD Grades 1 and 2, which was modified by gender (p