Independent Predictors of Fibrosis in Patients With Nonalcoholic Fatty Liver Disease

Background & Aims

Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease. We investigated factors associated with advanced fibrosis in NAFLD.

Methods

The study included 432 patients with histologically proven NAFLD (26.8% with nonalcoholic steatohepatitis [NASH] and 17.4% with moderate-to severe fibrosis). NASH was defined as steatosis, lobular inflammation, and ballooning degeneration with or without Mallory–Denk bodies and/or fibrosis. Fibrosis was classified into 2 groups: those with no or minimal fibrosis and those with moderate-to-severe fibrosis. Groups were compared using Mann–Whitney and chi-square method analyses. A model was constructed using a stepwise bidirectional method; its predictive power was measured using a 10-fold cross-validation technique.

Results

Patients with NASH were more likely to be male (P < .0001); have lower hip-to-waist ratios (P = .03); were less likely to be African American (P = .06); have higher levels of alanine aminotransferase (ALT; P < .0001), aspartate aminotransferase (AST; P < .0001), and serum triglycerides (P = .0154), but lower levels of high-density lipoprotein cholesterol (P < .0001). Patients with moderate-to-severe fibrosis were older (P = .0245); more likely to be male (P = .0189), Caucasian (P = .0382), have diabetes mellitus (P = .0238), and hypertension (P = .0375); and have a lower hip-to-waist ratio (P = .0077) but higher serum AST (P < .0001) and ALT (P < .0001) levels. The multivariate analysis model to predict moderate-to-severe fibrosis included male sex, Caucasian ethnicity, diabetes mellitus, and increased AST and ALT levels (model P value < .0001).

Conclusions

In patients with NAFLD, diabetes mellitus and aminotransferase levels are independent predictors of moderate-to-severe fibrosis. They can be used to identify NAFLD patients at risk for advanced fibrosis.

Abbreviations used in this paper: ALT, alanine aminotransferase, AST, aspartate aminotransferase, BMI, body mass index, NAFLD, nonalcoholic fatty liver disease, NASH, nonalcoholic steatohepatitis, PAF, probability of advanced fibrosis, ROC, receiver operating characteristic.