Liver Fibrosis Index-4 Does Not Correlate to Liver Elastography in Patients with Inflammatory Bowel Disease

<b>Background</b>: Inflammatory bowel disease (IBD) is associated with an increased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD). The Fibrosis-4 (FIB-4) index is a non-invasive tool for assessing liver fibrosis that has been validated in various liver diseases. The main objective of this study was to study whether the FIB-4 index is a reliable predictor of liver fibrosis, as assessed through elastography, in patients with IBD. We additionally aimed to analyze if FIB-4 associates with IBD characteristics such as lipid profile, subclinical carotid atherosclerosis, and insulin resistance indices. <b>Methods</b>: A cross-sectional study was conducted, enrolling 197 patients with IBD. Subjects underwent comprehensive clinical and laboratory evaluations. Hepatic fibrosis was assessed non-invasively using the FIB-4 index and transient elastography, while abdominal ultrasonography was performed to grade hepatic steatosis based on the degree of fat infiltration. To investigate the associations between disease characteristics and FIB-4 score and the correlation of this index to elastography, a multivariable linear regression analysis was conducted. <b>Results</b>: The presence of diabetes, hypertension, and metabolic syndrome was associated with significantly higher FIB-4 levels. However, FIB-4 did not show a relationship with disease characteristics such as phenotype or activity indices. Furthermore, FIB-4 did not demonstrate a correlation with liver stiffness values measured by elastography. <b>Conclusions</b>: Our findings suggest that the FIB-4 index may not be a reliable tool for assessing hepatic fibrosis in patients with IBD. This observation is particularly significant given the high prevalence of MASLD in the IBD population.