Association between CRP-TyG Index and Hepatic Synthetic Function in Post-Myocardial Infarction ICU Patients

Jiao Bao¹Jiejun Hu¹Xiangyin Lv^2*

• ¹Department of Emergency, Affiliated Dongyang Hospital, Wenzhou Medical University, Dongyang, China
• ²Department of Gastroenterology, Affiliated Dongyang Hospital, Wenzhou Medical University, Dongyang, China

Objective: To determine whether the CRP–TyG index (CTI)—a composite of systemic inflammation and insulin resistance—is independently associated with early hepatic synthetic function in post–myocardial infarction (MI) ICU patients within 24 hours. Methods: Single-center, retrospective cross-sectional study of 286 consecutive post-MI ICU patients (standardized laboratory sampling within 24 h). CTI integrated C-reactive protein with the triglyceride–glucose index. Outcomes were serum albumin (ALB), prealbumin (PA), and the total bilirubin-to-albumin ratio (TBIL/ALB). Associations were estimated using ordinary least squares with prespecified covariate adjustment; nonlinearity was tested using restricted cubic splines. Incremental discrimination was assessed via AUC, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Prespecified subgroups (sex, age ≤/>70 years) and sensitivity analyses (excluding deaths, pressor users, CRRT) evaluated robustness. Results: Higher CTI was independently associated with lower ALB (β per unit CTI = −1.23 g/L, p<0.001) and PA (β = −26.35 mg/L, p<0.001), but not with TBIL/ALB (β = 0.02, p=0.135). Compared with Q1, Q4 had lower ALB (−2.19 g/L, p=0.002) and PA (−56.05 mg/L, p<0.001), with linear dose–response supported by splines (ALB p-overall<0.001; PA p-overall<0.001; nonlinearity p>0.30). Adding CTI improved discrimination for ALB and PA, but not for TBIL/ALB. Effects were larger in males (per-unit: ALB −2.16 g/L; PA −38.92 mg/L) than females (ALB −0.92 g/L; PA −15.87 mg/L). Sensitivity analyses excluding deaths, pressor users, or CRRT yielded consistent estimates. Conclusions: Within 24 hours after myocardial infarction surgery, elevated CTI was associated with decreased albumin and prealbumin levels, but not TBIL/ALB ratio. The associations were the same across sex and age categories.