Effect of different classes of obesity on the pulmonary functions among adult Egyptians: a cross-sectional study

Introduction Obesity is a common chronic disease, representing a major health hazard. Obesity has several delirious effects on the respiratory functions. Aim of the study To study the effect of obesity on pulmonary functions among our local population of obese adults and to assess the correlation between the severity of lung function impairment and the degree of obesity. Patients and methods Healthy nonsmoker adult patients were recruited in our cross-sectional study. After full medical evaluation, measurement of height and weight, and calculation of BMI, patients underwent spirometry tests with measurement of forced expiratory volume in first second (FEV1), forced vital capacity (FVC), forced mid-expiratory flow, and peak expiratory flow rate. Then, they were classified according to their BMI into five groups. Results The study included 293 patients divided into five groups according to their BMI. Significant statistical differences were noticed between nonobese patients and patients with classes II and III obesity regarding FVC, FEV1, and forced mid-expiratory flow, but no differences regarding peak expiratory flow rate and FEV1/FVC ratio. Overall, 28.9% of the total obese patients presented with restrictive pattern of spirometry, 2.8% with obstructive, and 2.4% with mixed patterns. Conclusion Obesity of especially marked degrees with BMI of more than 35 kg/m2 negatively affects the spirometric parameters. Restrictive pattern was the commonest abnormality observed in the spirometry of obese patients.