Association between CRP-TyG index and hepatic synthetic function in post-myocardial infarction ICU patients

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 h.

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.

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.

Within 24 h 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.