ABSTRACT
To correlate the respiratory function among normal weight [BMI > 18.5 - 24.9 Kg/m[2]], overweight [BMI > 25 - 29.9 Kg/m[2]] and obese [BMI > 30 Kg/m[2]] male medical students who did not have evidence of obstructive or restrictive airway disease or other underlying diseases affecting their respiratory system. The other objective was to assess the correlation of respiratory function St body mass index [BMI]. Cross sectional controlled study was conducted among 113 eligible male medical students at college of medicine, King Saud University Riyadh, Kingdom of Saudi Arabia during August 2009 - July 2010. Body mass index was used to assess the obesity and forced expiratory volume in one second [FEV1] and forced vital capacity [FVC] were used to assess respiratory function. One way ANOVA was used to find the difference between BMI groups and bivariate correlation analysis was done to find out the strength of the relationship among BMI and respiratory function parameters. FEV1, FVC and FEV1/FVC ratio were linearly and mildly inversely related with BMI in overweight [r = -0.338, -0.291, -0.311 respectively] and obese [r = -0.375, -0.349, -0.040 respectively]. In normal weight subjects, FEV1 and FVC were mildly positively correlated [r = 0.136 and 0.219 respectively] and FEV1/FVC ratio was negatively correlated [r = -0.166] with BMI. Overweight and obesity are associated with pulmonary dysfunction among young male population