Abstract
Background: One of the world’s biggest health threats is obesity. This can contribute to various health conditions such as diabetes, vascular disorders, and osteoarthritis. Yet, there has been less focus on the impact of obesity on the respiratory system. Pulmonary function tests (PFTs) are commonly associated with the body’s size and age, where height is a predictor for the size of the chest, and age represents maturity.

Aim and Objective: This research was designed to show that any body mass index (BMI) rise would affect lung function.

Materials and Methods: We, therefore, tried to investigate the relationship between obesity and different variable of PFTs.

Results: The variable of pulmonary function tests such as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1)/FCV ratio was significantly decreased in obese individuals than normal individuals. However, FEV1, FEF25-75%, and peak expiratory flow rate (L/sec) were comparable among obese and normal-weight individuals. The linear correlation between BMI with FVC [r(43) = −0.033; P = 0.0829] and BMI with FEV1/FVC ratio [r(43) = −0.111; P = 0.4666] was not observed. This suggests that BMI does not determine the significant change in the FVC and FEV1/FVC ratio among obese individuals.

Conclusion: We discovered a significant relationship between obesity and PFT and concluded that, as shown by the significant decrease in FVC, obesity induces significant changes in respiratory function, and the significant increase in FEV1/FVC ratio indicates a restrictive lung function pattern among obese individuals. However, the correlation analysis suggests that BMI is not a detrimental factor for PFT alteration in obesity. BMI is, therefore, not a significant predictor of PFT. When interpreting PFT outcomes in patients, our findings will assist clinicians.

Key words: Body Mass Index; Obesity; Forced Vital Capacity; Forced Expiratory Volume in One Second/Forced Vital Capacity and Pulmonary Function Tests