Impact of Obesity on Forced Vital Capacity among Adult Males: A Cross-Sectional Study
Background: Obesity has a substantial impact on respiratory physiology and is a rapidly growing global health concern. Excess adipose tissue deposition, particularly in the thoracic and abdominal regions, alters lung mechanics and results in reduced lung volumes. One important measure of pulmonary function that captures lung capacity and chest wall mechanics is forced vital capacity, or FVC.
Objective: To evaluate the impact of obesity on Forced Vital Capacity in adult males aged 30–60 years.
Methods: A cross-sectional comparative study was conducted on 200 healthy male subjects aged 30–60 years, who were divided into obese (BMI ≥30 kg/m², n=100) and non-obese groups (BMI 18.5– 24.9 kg/m², n=100). FVC was measured using computerized spirometry, and the best of three acceptable manoeuvres was recorded. Statistical analysis included Student’s unpaired t-test, Pearson’s correlation coefficient, 95% confidence intervals, and effect size estimation.
Results: The mean FVC in non-obese subjects was 2.76 ± 0.50 L, whereas in obese subjects it was 1.94 ± 0.30 L. The mean difference was 0.82 L (95% CI: 0.70–0.94), which was statistically significant (t = 15.1, p < 0.001). Percentage predicted FVC was also significantly lower in obese subjects (71.0 ± 6.2% vs 87.5 ± 4.5%, p < 0.001). A significant negative correlation between BMI and FVC (r = –0.56, p < 0.001) was observed.
Conclusion: Obesity is associated with a significant reduction in Forced Vital Capacity, indicating restrictive pulmonary changes.
Keywords: Obesity, Body Mass Index, Forced Vital Capacity, Pulmonary Function.
