The Role of the Triglyceride–Glucose Index and Its Derivatives in Predicting the Risk of Metabolic Dysfunction–Associated Steatotic Liver Disease and Hepatic Fibrosis

Background Metabolic dysfunction–associated steatotic liver disease (MASLD) has emerged as a major global health burden due to its increasing prevalence and its substantial contribution to liver-related morbidity and mortality. In primary care settings, simple, non-invasive, and cost-effective diagnostic biomarkers are needed to facilitate early detection. Methods This retrospective cross-sectional study included 408 adults attending a family medicine outpatient clinic between January 2023 and December 2024. Following the exclusion of secondary causes, MASLD was diagnosed in accordance with current diagnostic criteria and imaging findings. Liver fibrosis risk was evaluated using the Fibrosis-4 (FIB-4) index. The triglyceride–glucose (TyG) index and its composite derivatives—TyG × body mass index (TyG-BMI), TyG × waist circumference (TyG-WC), and TyG × waist-to-height ratio (TyG-WHtR)—were calculated. Multivariable logistic regression and receiver operating characteristic (ROC) analyses were performed. Results MASLD was present in 50.5% of participants. All TyG-related indices demonstrated significant dose–response associations with MASLD (p < 0.001). In fully adjusted analyses, participants in the highest quartile of TyG-WC had a 14.46-fold higher odds of MASLD compared with the lowest quartile (95% CI: 6.85–30.56; p < 0.001). ROC analysis showed that TyG-WC had the highest discriminative performance (AUC: 0.761), followed by TyG-WHtR (AUC: 0.752) and TyG-BMI (AUC: 0.750). Subgroup analyses revealed stronger diagnostic performance in younger individuals and those without hypertension or diabetes. Conclusions TyG and its anthropometric derivatives, particularly TyG-WC, are independently associated with MASLD and show moderate diagnostic accuracy. These easily accessible indices may serve as practical screening tools for MASLD in primary care settings.