Discordance Between FIB-4 and BAST Fibrosis Risk Classifications in Obese Patients with MASLD: Results from the OBREDI-TR Study
Year: 2026
Type: article
Abstract: Background/Objectives: Non-invasive fibrosis scores are widely used for risk stratification in metabolic dysfunction–associated steatotic liver disease (MASLD); however, their performance in obese individuals remains controversial. The Fibrosis-4 index (FIB-4) is commonly recommended as a first-line tool, yet may underestimate fibrosis risk in severe obesity. The BAST score, which incorporates metabolic and anthropometric parameters, has been proposed as an alternative. This study aimed to characterize both the degree and direction of discordance between FIB-4 and BAST in obese patients with MASLD. Methods: This predefined secondary analysis included 2,950 adults with obesity (BMI ≥30 kg/m²) and MASLD from the multicenter OBREDI-TR cohort. Fibrosis risk categories were assigned using standard cut-offs for FIB-4 and BAST. Agreement was assessed using weighted Cohen’s kappa. Associations between discordance patterns, obesity class, and visceral adiposity index (VAI) were evaluated using chi-square tests and general linear models. Results: Overall agreement between FIB-4 and BAST was very poor (κ = 0.041, p < 0.001). Discordance was observed in 22.3% of patients and increased markedly with obesity severity. In class III obesity, discordance was predominantly driven by low-risk classification according to FIB-4 despite high-risk classification by BAST. Patients with this discordant pattern exhibited significantly higher VAI values compared with concordant cases (p < 0.001), independent of study center. Conclusions: In obese patients with MASLD, particularly those with morbid obesity, FIB-4 frequently classifies patients as low risk while BAST identifies elevated fibrosis risk. This systematic discordance suggests that FIB-4 may underestimate fibrosis burden in the context of severe obesity and visceral adiposity, supporting the need for a phenotype-oriented, multimodal approach to fibrosis risk assessment.
Source: Diagnostics
Authors: Ozge Kama Basci, Alihan Oral, Ali Kirik, Hacer Sen, Ihsan Solmaz, Ulas Serkan Topaloglu, Ismail Demir, Ahmet Dundar, Emine Binnetoglu, Nalan Okuroglu, Ahmet Aydin, Zeynep Irmak Kaya, Hamit Yildiz, Aycan Acet, Gokhan Tazegul, Osman Ozudogru, Kubilay Issever, Selcuk Yaylacı, Ugur Bayram Korkmaz, Nur Duzen Oflas, Celalettin Küçük, Kamil Konur, Teslime Ayaz, Aysun Isiklar, Esref Arac, Hilmi Erdem Sumbul, Huseyin Ali Ozturk, Ali Burak Govez, Yusuf Usame Durmus, Atilla Onmez, Sibel Ocak Serin, Nizameddin Koca, Nazif Yalcin, Aysegul Ertinmaz, Alper Tuna Guven, Mehmet Kok, Yasin Sahinturk, Seyit Uyar, Hasan Sozel
Institutions: Balıkesir University, Biruni University, Diyarbakır Gazi Yaşargil Eğitim ve Araştırma Hastanesi, Izmir Bozyaka Eğitim ve Araştırma Hastanesi, Fatih Sultan Mehmet Eğitim Ve Araştırma Hastanesi, Istanbul Medipol University, Eskişehir City Hospital, Sağlık Bilimleri Üniversitesi, Gaziantep University, Kutahya Saglik Bilimleri Universitesi, Marmara University, Erzincan Binali Yıldırım University, Giresun University, Sakarya University, Izmir Kâtip Çelebi University, Recep Tayyip Erdoğan University, Bakırçay Üniversitesi, Acıbadem University, Dicle University, Adana Hospital, Düzce Üniversitesi, Ümraniye Eğitim ve Araştırma Hastanesi, Bursa City Hospital, Başkent University, Antalya Eğitim ve Araştırma Hastanesi, Akdeniz University
Language: English
Subfield: Epidemiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7128724591