The Effect Of Metabolic And Bariatric Surgery(MBS) On Obese Patients With NAFLD

Objective:To determine the effect of MBS on obese patients with NAFLD.Methods:Clinical data of morbid obese patients who were admitted to Department of General Surgery,Shanghai 9th People’s Hospital between January 2016 and January 2019,were reviewed retrospectively.We observed the clinical characteristics and explored NAFLD-related risk factors at baseline;evaluated the change in obesity,metabolism,NAFLD and sleep-disordered breathing conditions;and discussed the impacts on surgical effects 12 months after MBS by bivariate correlation analysis and liner regressions analysis.Results:Of the 185 morbidly obese patients,a total of 157 obese patients with NAFLD were included in this study,after excluding 7 overdrinkers,5undergoing revision surgery,and 16 without complete clinical data or losing to follow-up,including 80 cases（51%）with mild NAFLD,45 cases（28.7%）with moderate NAFLD,and 32 cases（20.3%）with severe NAFLD.155 of these patients had concomitant OSA at the same time（98.7%）.There were significant differences（P<0.05）in obesity（body mass index,BMI;waist circumference,WC;hip circumference,HC,waist hip ration,WHR）,glucose metabolism（homa insulin-resistance.HOMA-IR）,lipid metabolism（total cholesterol,TC;low density lipoprotein cholesterol,LDL-C）,liver function（alanine aminotransferase,ALT;aspartate aminotransferase,AST;gamma-glutamyl transpeptidase,GGT）,and sleep breathing severity（apnea hypopnea index,AHI;mean oxygen saturation,MSO₂;nadir oxygen saturation,NSO₂;oxygen saturation less than 90%in total sleep time,SIT90）among three groups.Preoperative liver/spleen Hounsfield units ratio（LSR）is significantly negatively correlated with BMI,WC,HOMA-IR,TC,LDL-C,AHI,and SIT90（P<0.05）;and significantly positively correlated with MSO₂ and NSO₂（P<0.05）,indicating that there were correlations between the severity of liver steatosis and that of obesity,IR,dyslipidemia,abnormal liver function,sleep apnea as well as nocturnal hypoxemia,respectively.MBS achieved significant improvement 12 months after surgery（P<0.05）,without any differences among postoperative indicators of all three groups（P>0.05）.In addition,there was significant positive correlation between the change in LSR（ΔLSR）and the change in AHI（ΔAHI）after surgery,while the results of the univariate and multivariate linear regression analysis only supported preoperative LSR as an independent predictor of the effect of MBS on liver steatosis.Conclusion:The present study shows that as for the obese patients with NAFLD,the severity of hepatic steatosis is associated with abdominal obesity,IR,dyslipidemia,abnormal liver function,and concomitant OSA;one year after MBS,the condition of patients is improved significantly,and the change in liver steatosis is correlated with the change in sleep apnea.;the result of multivariate analysis indicates that preoperative liver steatosis is an independent predictor of surgical efficacy.The specific mechanism and long-term efficacy remain to be studied.