Risk of extrahepatic events high among NAFLD patients with severe liver scarring

Among patients with nonalcoholic fatty liver disease (NAFLD), the more severe the liver fibrosis, the higher the risk of developing extrahepatic events, a study has found. Specifically, the risk is low among patients with mild fibrosis, low but clinically relevant among those with moderate fibrosis, and high among those with severe to advanced fibrosis.

The study involved 2,135 patients with biopsy-confirmed NAFLD. Researchers looked at cumulative incidence functions (CIFs) to assess the risk of liver-related and extrahepatic events, stratified by fibrosis scores (F0–F4). They used cause-specific Cox model and predicted CIFs to identify predictors of the said outcomes.

Observed CIFs showed that the 60-month probabilities of liver-related and extrahepatic events were 0.2 percent and 3 percent among patients with F0-F1, 2 percent and 3.8 percent among those with F2, and 9.7 percent and 6.4 percent among those with F3-F4, respectively.

In the cause-specific Cox model, age >50 years (hazard ratio [HR], 2.7) was the sole predictor of liver-related events among F0-F1 and F2 patients. On the other hand, predictors of extrahepatic events in these patient groups included age >50 years (HR, 2.96), previous cardiovascular events (CVE; HR, 2.07), and previous extra-hepatic cancer (HR, 2.36).

Among patients with F3-F4, the risk factors for liver-related events were age >55 years (HR, 1.73), obesity (HR, 1.52), platelet count <150,000/mmc (HR, 3.66), and log gamma glutamyl transferase (HR, 1.77). Extrahepatic events, meanwhile, were associated with age >55 years (HR, 1.74) and previous CVE (HR, 2.51).

Predicted CIFs for hepatic and extrahepatic events among patients with F0-F1, F2, and F3-F4 stratified the risk of events. The results were replicated in an external cohort of NAFLD patients with liver fibrosis severity estimated by liver stiffness measurement by transient elastography.