Liver biopsy is considered as the gold standard for assessing nonalcoholic fatty liver disease (NAFLD) histologic lesions in patients with morbid obesity. The aim of this study was to determine the diagnostic utility of noninvasive markers of fibrosis (FibroTest), steatosis (SteatoTest), and steatohepatitis (NashTest, ActiTest) in these patients.
Materials and methods
Two hundred and eighty-eight patients presenting with interpretable baseline operative biopsy and biomarkers, in an ongoing prospective cohort of patients treated with bariatric surgery, were included. Histology (NAFLD activity score, or NAFLD scoring system) and biochemical measurements were centralized and blinded to other characteristics. The area under the receiver operating characteristic curves (AUROC), sensitivity, specificity, positive and negative predictive values were assessed. Weighted AUROC (Obuchowski method) was used to prevent multiple testings and a spectrum effect.
The prevalence of advanced fibrosis (bridging) was 6.9%, advanced steatosis (>33%) was 48%, and steatohepatitis was 6.9% (NAFLD scoring system>4). Weighted AUROCs of the tests were as follows (mean, 95% confidence interval, significance): FibroTest for advanced fibrosis: 0.85, 0.83–0.87, P<0.0001; SteatoTest for advanced steatosis: 0.81, 0.79–0.83, P<0.0001; and ActiTest for steatohepatitis: 0.77, 0.73–0.81, P<0.0001.
In patients with morbid obesity, the diagnostic performances of the FibroTest, SteatoTest, and ActiTest were statistically significant, thereby possibly reducing the need for biopsy in this population.