Discordance Between FIB-4 and BAST Fibrosis Risk Classifications in Obese Patients with MASLD: Results from the...

Area of Science:

• Hepatology
• Metabolic Disorders
• Obesity Medicine

Background:

• Non-invasive fibrosis scores are crucial for risk stratification in metabolic dysfunction-associated steatotic liver disease (MASLD).
• The performance of the Fibrosis-4 (FIB-4) index in obese individuals with MASLD is debated, with potential underestimation of fibrosis risk.
• The BAST score, incorporating metabolic and anthropometric data, is proposed as an alternative for fibrosis assessment in MASLD.

Purpose of the Study:

• To evaluate the discordance in fibrosis risk classification between FIB-4 and BAST scores in obese patients with MASLD.
• To analyze how obesity severity and visceral adiposity influence the agreement between FIB-4 and BAST scores.

Main Methods:

• A secondary analysis of 2950 obese adults with MASLD from the OBREDI-TR cohort.
• Fibrosis risk categorization using standard cut-offs for FIB-4 and BAST scores.
• Assessment of agreement using weighted Cohen's kappa and evaluation of discordance patterns with obesity class and visceral adiposity index (VAI).

Main Results:

• Very poor agreement (κ = 0.041) was found between FIB-4 and BAST scores.
• Discordance occurred in 22.3% of patients, increasing with obesity severity.
• In class III obesity, FIB-4 often indicated low risk while BAST indicated high risk, associated with higher VAI.

Conclusions:

• FIB-4 may underestimate fibrosis risk in obese MASLD patients, particularly those with morbid obesity and high visceral adiposity.
• The BAST score appears more sensitive in identifying elevated fibrosis risk in this population.
• A phenotype-oriented, multimodal approach is recommended for accurate fibrosis risk assessment in obese MASLD patients.