Simple noninvasive systems predict long-term outcomes of patients with nonalcoholic fatty liver disease

Abstract

Background & aims: Some patients with nonalcoholic fatty liver disease (NAFLD) develop liver-related complications and have higher mortality than other patients with NAFLD. We determined the accuracy of simple, noninvasive scoring systems in identification of patients at increased risk for liver-related complications or death.

Methods: We performed a retrospective, international, multicenter cohort study of 320 patients diagnosed with NAFLD, based on liver biopsy analysis through 2002 and followed through 2011. Patients were assigned to mild-, intermediate-, or high-risk groups based on cutoff values for 2 of the following: NAFLD fibrosis score, aspartate aminotransferase/platelet ratio index, FIB-4 score, and BARD score. Outcomes included liver-related complications and death or liver transplantation. We used multivariate Cox proportional hazard regression analysis to adjust for relevant variables and calculate adjusted hazard ratios (aHRs).

Results: During a median follow-up period of 104.8 months (range, 3-317 months), 14% of patients developed liver-related events and 13% died or underwent liver transplantation. The aHRs for liver-related events in the intermediate-risk and high-risk groups, compared with the low-risk group, were 7.7 (95% confidence interval [CI]: 1.4-42.7) and 34.2 (95% CI: 6.5-180.1), respectively, based on NAFLD fibrosis score; 8.8 (95% CI: 1.1-67.3) and 20.9 (95% CI: 2.6-165.3) based on the aspartate aminotransferase/platelet ratio index; and 6.2 (95% CI: 1.4-27.2) and 6.6 (95% CI: 1.4-31.1) based on the BARD score. The aHRs for death or liver transplantation in the intermediate-risk and high-risk groups compared with the low-risk group were 4.2 (95% CI: 1.3-13.8) and 9.8 (95% CI: 2.7-35.3), respectively, based on the NAFLD fibrosis scores. Based on aspartate aminotransferase/platelet ratio index and FIB-4 score, only the high-risk group had a greater risk of death or liver transplantation (aHR = 3.1; 95% CI: 1.1-8.4 and aHR = 6.6; 95% CI: 2.3-20.4, respectively).

Conclusions: Simple noninvasive scoring systems help identify patients with NAFLD who are at increased risk for liver-related complications or death. NAFLD fibrosis score appears to be the best indicator of patients at risk, based on HRs. The results of this study require external validation.

Keywords: ALT; APRI; AST; AST/platelet ratio index; BMI; HCC; NAFLD; NAFLD fibrosis score; NAFLD-FS; NASH; ROC; aHR; adjusted hazard ratio; alanine aminotransferase; aspartate aminotransferase; body mass index; hepatocellular carcinoma; nonalcoholic fatty liver disease; nonalcoholic steatohepatitis; receiver operating characteristic.

Figure 1

Values of the scores by fibrosis stage. Bars represent the mean values (P < .001 for each score).