Evaluation Of The Effect Of Metabolic Surgery On NAFLD In Patients With BMI≥ 32.5kg/m~2 Based On Transient Elastography

Objective:To evaluate the hepatic lipid content and fibrosis in patients with body mass index(BMI)≥ 32.5 kg/m2 combined with nonalcoholic fatty liver disease(NAFLD)three months following metabolic surgery,and explore the predictive factors of hepatic steatosis and fibrosis outcomes short-term after metabolic surgery based on transient elastography.Methods:Fifty patients with BMI≥ 32.5 kg/m2 and NAFLD underwent metabolic surgery were enrolled.Transient elastography was used to detect liver steatosis and fibrosis before operation,one month and three months after surgery.Liver function,glycolipid metabolism,and body composition were detected and predictors of liver steatosis and fibrosis outcome were assessed as well.Results:1.In terms of hepatic steatosis,82%of the patients had severe steatosis before metabolic surgery,and the condition gradually improved with increased reliever and decreased severe fatty liver(P<0.05);15%preoperative severe steatosis patients were relieved three months following operation;The percentage of total weight loss(%TWL)of the patients with remission of steatosis or conversion to mild steatosis were more than 20%three months after the surgery;The proportion of percentage of reduction in excess weight loss(%EWL)>50%was higher in the patients with remission of steatosis than other patients and was the lowest in the patients containing severe steatosis three months after the surgery(P<0.05).2.As for liver fibrosis,80%of patients had liver stiffness(LSM)≥ 8 kPa preoperatively,which gradually decreased and more patients had LSM<8 kPa gradually following surgery(P<0.05),resulted in 58%patients had LSM≥ 8kPa preoperative received LSM<8kPa three months after metabolic surgery.3.Three months after surgery,body weight,BMI and waist circumference were significantly lower than those before surgery(P<0.05),and the mean value of percentage of total weight loss(%TWL)and percentage of excess weight loss(%EWL)exceeded 20%and 50%respectively.4.Alanine aminotransferase(ALT),aspartate aminotransferase(AST)andγ-glutamyltranspeptidase(GGT)were continuous improved one and three months after metabolic surgery(P<0.05);Glucose metabolism markers,such as fasting blood glucose(FBG),fasting insulin(FIN),glycosylated hemoglobin(HbA1c)and insulin resistance index(HOMA-IR)were significantly decreased one and three months following surgery(P<0.05);Lipid metabolism indicators triglyceride(TG),totoal cholesterol(TC),and low-density lipoprotein cholesterol(LDL-C)were significantly decreased,high-density lipoprotein cholesterol(HDL-C)was significantly increased one and three months after metabolic surgery(P<0.05).5.In terms of body composition,body fat,obesity degree,body fat percentage,visceral fat area(VFA),muscle mass,fat-shedding weight,skeletal muscle and basal metabolic rate(BMR)of patients with NAFLD were significantly decreased three months after metabolic surgery(P<0.05).6.Smaller waist circumference before the operation predicted more likely relieved hepatic steatosis,and lower preoperative BMI and HOMA-IR helped to possibility of LSM<8 kPa three months following metabolic surgery.Conclusions:Patients with BMI≥ 32.5 kg/m2 who suffered from NAFLD showed improvement in liver steatosis and fibrosis,reduction in body weight,waist circumference and BMI,and relieved liver function,metabolism disorders and insulin resistance three months after metabolic surgery.Preoperative smaller waist circumference facilitated the remission of liver steatosis in the short term after surgery.While lower preoperative BMI and insulin resistance were beneficial to the relief of liver fibrosis in the short term.Effective weight loss is the key factor for the improvement of NAFLD in the short term after metabolism.Transient elastography as a quantitative method for measurement of hepatic steatosis and fibrosis can intuitively and quantitatively assesses the effect of metabolic surgery on NAFLD.