EFFECT OF ENDOSCOPIC BARIATRIC AND METABOLIC THERAPIES ON BIOMARKERS OF NONALCOHOLIC FATTY LIVER DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background: Weight loss via lifestyle intervention remains the mainstay of treatment for nonalcoholic fatty liver disease (NAFLD). Endoscopic bariatric and metabolic therapies (EBMTs) have recently been developed as an alternative treatment option for obesity. To date, there are 7 EBMTs that are FDA approved including 3 intragastric balloons (IGBs), a suturing device used for endoscopic sleeve gastroplasty (ESG), a tissue plication device used for primary obesity surgery endoluminal (POSE), aspiration therapy (AT) and transpyloric shuttle (TPS). Aim: To assess the effect of currently approved EBMTs on NAFLD biomarkers. Methods: Study Design: Systematic review and meta-analysis. Data Sources, Selection and Synthesis: MEDLINE, EMBASE, Web of Science and Cochrane Central through Nov 1, 2019. Studies that assessed the effect of currently approved EBMTs on liver outcomes in patients with obesity were included. Randomized controlled trials and observational studies that were published as full text articles or presented as conference abstracts were included. If cohorts overlapped, the study with more patients was selected. Studies evaluating the effect of investigational EBMTs or those with fewer than 5 patients were excluded. Authors were contacted for additional data. Data were pooled using a fixed-effects model or random-effects for high heterogeneity. Primary Outcomes: Histologic, radiologic and serological biomarkers of NAFLD. Secondary Outcomes: Non-liver metabolic parameters including weight, body mass index (BMI), waist circumference, insulin resistance and hemoglobin A1c. Results: Of 4,401 potential studies, 24 studies with 1,223 patients were included. Mean age and BMI were 31.5-56 years and 30.3-65 kg/m2. Twenty studies evaluated IGB, 2 evaluated ESG and 2 evaluated AT. No studies reported liver outcomes following POSE or TPS. The median intervention duration was 6 [5.27,12] months. Pooled average weight loss was 13.10% total weight loss (95% CI, 12.02 to 14.17, p<0.0001, I2=0%). Primary Outcomes: Following EBMT, there were statistically significant improvements in liver biomarkers, including alanine aminotransferase (-9.44 U/L; 95% CI, -12.12 to -6.76; p<0.0001), histologically or radiologically measured liver steatosis (standardized mean difference: -1.77; 95% CI, -3.09,-0.45, p=0.008), histologically or radiologically measured liver fibrosis/stiffness (standardized mean difference: -1.62; 95% CI, -2.83,-0.42, p=0.008) and histologic NAFLD activity score (-2.50; 95% CI, -3.48,-1.52; p<0.0001) (Table 1). Secondary Outcomes: Other metabolic parameters also improved following EBMTs including waist circumference, fasting glucose, fasting insulin and insulin resistance (Table 1). Conclusion: EBMT appears effective at treating NAFLD with significant improvement in fibrosis as well as other histologic, radiologic and serological markers of disease.