Association between the C-Reactive Protein-Triglyceride-Glucose Index and Mortality in Patients with Metabolic Dysfunction-Associated Fatty Liver Disease

Objective The C-reactive protein (CRP)-triglyceride-glucose (TyG) index (CTI) is a clinical marker that simultaneously reflects inflammation and insulin resistance (IR) and is associated with adverse cardiovascular outcomes. However, its prognostic value in metabolic dysfunction-associated fatty liver disease (MAFLD) remains unclear. This study aimed to investigate the associations of CTI with all-cause and cardiovascular disease (CVD) mortality in patients with MAFLD. Methods Data were utilized from adults who participated in the National Health and Nutrition Examination Survey (NHANES) III (1988–1994), with their records linked to mortality data from the National Death Index (NDI). CTI was calculated as 0.412 × Ln(CRP [mg/L]) + Ln( (triglycerides [mg/dL] × fasting glucose [mg/dL]) / 2 ). To assess the association between CTI and mortality, we employed multivariable Cox proportional hazards models, restricted cubic splines (RCS) analysis, and Kaplan-Meier curves. Furthermore, stratified analyses were conducted to evaluate potential heterogeneity across subgroups. Results Among 3,102 MAFLD participants, RCS analyses revealed significant non-linear associations between CTI and mortality risks (both P < 0.05), with inflection points at CTI = 8.1. After comprehensive adjustment,participants in the highest CTI tertile exhibited significantly elevated risks of both all-cause mortality (HR = 1.58,95% CI 1.23–2.02) and CVD mortality (HR = 2.09, 95% CI 1.33–3.28) compared to those in the lowest tertile. Conclusions Elevated CTI exceeding the threshold of 8.1 was independently associated with significantly increased risks of all-cause and CVD mortality. These findings establish CTI as a novel prognostic biomarker for long-term mortality risk stratification in patients with MAFLD.