Relationship between the Change in Body Weight or Body Mass Index and Pulmonary Function

ABSTRACT

BACKGROUND: Obesity and deterioration of pulmonary function are known to increase all-cause mortality and morbidity associated with chronic diseases. Obesity is a known risk factor for decreasing pulmonary function; however, studies on the effect of changes in body weight or body mass index (BMI) on pulmonary function are rare. This study aimed to investigate the relationship between the change in body weight or BMI and the pulmonary function test (PFT) in Koreans who underwent consecutive screening at a health promotion center. METHODS: We enrolled 5,032 patients who underwent consecutive screening health check-ups at a health promotion center in 2015 and 2017. The BMI was calculated as the body weight (kg) divided by the square of the height (m²) in 2015 and 2017. We analyzed the association between the change in body weight or BMI and PFT. RESULTS: In males, PFT and changes in body weight were associated with forced expiratory volume in 1 second (FEV₁) but not with changes in BMI. In females, FEV₁/forced vital capacity and forced expiratory flow between 25–75% of vital capacity (FEF(25−75%)) were significantly associated with the changes in body weight and BMI. A correlation analysis between body weight and BMI showed a negative correlation with FEF(25−75%) in males. In females, FEV₁/FVC and FEF(25−75%) were negatively correlated. CONCLUSIONS: We observed that the increase in body weight and BMI was significantly associated with pulmonary function. This finding suggests that careful monitoring of body weight and BMI may aid in maintaining proper pulmonary function, thereby, reducing mortality and morbidity.