Non-Alcoholic Fatty Liver Disease (NAFLD) is common in Type 2 Diabetes Mellitus (T2DM). The FIB-4 index is one of the most-studied non-invasive biomarkers that combines age and laboratory parameters (platelet count, alanine-and aspartate- aminotransferase) to evaluate underlying hepatic fibrosis. This study aims to determine the diagnostic value of Fibrosis-4 (FIB-4) index scoring in screening for non-alcoholic fatty liver disease in patients with type 2 diabetes mellitus, which is a high-risk population in development of advance fibrosis.

A single center, analytical cross-sectional study was conducted among adult T2DM patients with and without NAFLD seen at the Out-Patient Department (OPD) and those with NAFLD enrolled under the Liver Disease Databank of the Liver Disease and Transplant Center in collaboration with Research and Biotechnology Division at St. Luke’s Medical Center, Quezon City. Medical history was obtained by reviewing charts of eligible patients using data collection form. Liver ultrasound was used as the reference standard in the diagnosis of NAFLD. The FIB-4 index was calculated with this formula: age (years) x AST (U/L)/(platelets (10^9/L) x ALT (U/L)^1/2.

A total of 305 adult patients with type 2 diabetes mellitus were included in the study. The prevalence of non-alcoholic fatty liver disease based on ultrasound among diabetic patients is 76.07%. The median age (p = 0.0204), AST (p < 0.00001), ALT (p < 0.00001) were significantly higher in patients with NAFLD than those without. Platelet count (p = 0.0002) was significantly lower in patients with NAFLD than those without. The proportion of patients with low platelet count, high AST and high ALT were significantly higher in patients with NALFD than those without. In this study, the FIB-4 index cutoff score for screening of NAFLD is ≥0.76, which has an accuracy of 66.23%, sensitivity of 75%, specificity of 38.3%, PPV of 79.46% and NPV of 32.56% in detecting fatty liver.

A FIB-4 index value of ≥0.76 has an acceptable sensitivity for screening NAFLD even in the absence of fibrosis among patients with T2DM. However, due to its low specificity, additional tests to establish NAFLD diagnosis may be required.