The effect of bariatric surgery on pulmonary function in the morbidly obese patients: A prospective before-after study

Background and aims: Obesity is one of the challenging public health issues which can increase the risk of different morbidities like respiratory disorders. Some studies suggested that significant weight loss may be associated with the improvement of pulmonary function in morbid obese patients. Bariatric surgeries are the most effective was for significant weight loss in morbid obese patient. The aim of this study was to determine the effects of bariatric surgery on the pulmonary function in the morbid obese patients. Methods: This prospective, before-after study was conducted on morbid obese patients who underwent bariatric surgery in Loghman Hakim hospital during 2019. All morbid obese patient (BMI ≥ 40) who presented to the hospital in the study period were included in the study by convenience sampling. Patient’s demographics and results of spirometry test variables were recorded in a questionnaire before the surgery and three months after the surgery. SPSS software version 25 was used for data analysis. Results: Thirty-eight patients were entered in the final analysis. The mean age of patients was 39.2±11.6 (range: 15-65). Fifteen patients in this study were male (39.5%). There were significant relations in the values of BMI, FEV1, FEV1/FVC before and after the surgery. In addition, there were significant negative correlation between FEV1 and BMI. Furthermore, functional dyspnea and obstructive sleep apnea were seen in 50% and 21% of patients which completely improved after the study. Conclusion: Bariatric surgery has significant effects on the improvement of pulmonary function in morbid obese patients.