Improvement of pulmonary function in obese patients after bariatric surgery
LI Yaxi,XIE Shuanshuan,WANG Changhui
(Department of Respiratory and Critical Care Medicine， Shanghai Tenth People’s Hospital，School of Medicine， Tongji University， Shanghai 200072, China)
ObjectiveTo investigate the changes of pulmonary function in obese patients after bariatric surgery. MethodsFifty-one obese patients who underwent bariatric surgery in Shanghai Tenth People’s Hospital from January 2019 to December 2021 were enrolled in the study. The pulmonary function indexes VC, IC, ERV, RV, FRC, TLC, FEV1, FVC, FEV1/FVC, MEF75, MEF50, MEF25, MMEF, PEF and DLCO of patients before and after surgery were compared by paired T test or Wilcoxon matched pair sign rank test. Spearman or Pearson correlation analysis was used to determine the correlation between ΔBMI and the improvement of lung function indexes. The VC%, IC%, ERV%, RV%, FRC%, TLC%, FEV1%, FVC%, MEF75%, MEF50%, MEF25%, MMEF%, PEF%, DLCO% were compared between healthy subjects and obese patients one year after surgery by Mann-Whitney U test. ResultsThe pulmonary indexes VC, ERV, TLC, FRC, RV, FVC, FEV1, FEV1/FVC, PEF, MEF75, MEF50, MEF25, MMEF, DLCO after bariatric surgery were significantly increased（all P<0.05), and IC was significantly decreased（P<0.05) compared with those before surgery. The decrease of BMI was negatively correlated with the decrease of MEF25, RV and FRC (P<0.05). One year after weight loss surgery, VC%, ERV%, FVC%, FEV1%, MEF25%, MMEF%, FRC%, RV%, DLCO% of obese patients were significantly increased（P<0.05), and PEF% decreased compared with healthy controls（P<0.05); while there were no significant differences in IC%, FEV1/FVC%, MEF75%, MEF50%, TLC% between obese patients and healthy subjects. ConclusionAfter bariatric surgery, the degree of obesity in patients is reduced, pulmonary ventilation function and diffusion function are improved significantly. Changes in pulmonary function caused by obesity are highly reversible, which can be significantly recovered by active weight loss.