Evolution of Non-alcoholic Fatty Liver Disease (NAFLD) Biomarkers in Response to Weight Loss 1 Year After Bariatric Surgery-a Post Hoc Analysis of the FibroTest Prospective Study.

BACKGROUND

Bariatric surgery is among the therapeutic options for non-alcoholic fatty liver disease (NAFLD), affecting 90% of patients with obesity. The aim of this study was to evaluate the evolution of NAFLD lesions 1 year after surgery using noninvasive markers.

METHODS

From November 2011 to November 2012, 253 patients with obesity undergoing bariatric surgery in three French University Hospitals were included. Histological data regarding intraoperative liver biopsy were collected at baseline, clinical, and biological data, including FibroTest®, SteatoTest®, and NASHTest®, before and after surgery.

RESULTS

Fibrosis' prevalence was 74.2% with a positive predictive value (PPV) for FibroTest® of 78.6% and 43.4% for significant fibrosis (Kleiner ≥ F2) with a negative predictive value (NPV) of 56.1%. NAFLD's prevalence was 84% with a PPV for SteatoTest® of 85.9% and 7.7% for NASH with an NPV for NASHTest® of 93.8%. One year after bariatric surgery, mean BMI had significantly decreased from 46.5 to 31.7 kg/m (p < 0.001). Fibrosis assessed by the FibroTest® showed that 82.5% of patients were F0 after surgery compared to 90.9% before. Using SteatoTest®, the percent of patient without steatosis (S0) increased from 1.6 to 49.6% after surgery, and rate of severe steatosis (S3) improved from 43.3 to 3.9%. NASHTest® revealed that the percent of patients without NASH increased from 12.8 to 73.6% and rates of NASH improved from 12 to 0.8%.

CONCLUSIONS

Validated noninvasive biomarkers SteatoTest® and NASHTest® suggested NAFLD and steatohepatitis improvement after bariatric surgery and might be useful tools for patient follow-up. Regarding fibrosis, FibroTest® was not accurate in patients with extreme obesity.