C-Reactive Protein–Triglyceride–Glucose Index and Risk of Incident Stroke Among Adults With Diabetes or Prediabetes: A Prospective Cohort Study From CHARLS

Background: The relationship between the C-reactive protein–triglyceride–glucose index (CTI)) and stroke risk remains unclear. This study aimed to clarify this association for the first time in a cohort of middle-aged and elderly individuals with diabetes or prediabetes. Methods: We consecutively enrolled 6,350 participants aged ≥ 45 years at baseline from the China Health and Retirement Longitudinal Study (CHARLS) who had diabetes or prediabetes in 2011 but no prior history of stroke. The CTI value is calculated using the formula: 0.412 × ln(CRP (mg/L)) + ln(TG (mg/dL)) × FPG (mg/dL)². The outcome was incident stroke, identified through physician diagnosis self-reports during follow-up (2013–2020). Cox proportional hazards models generalized additive models were employed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for stroke. Results: The 6,350 participants had a mean age of 59.5 ± 9.1 years at baseline; 52% were female. Over a median follow-up of 9.1 years, 638 individuals developed stroke (cumulative incidence 10.0%). Baseline CTI was positively associated with incident stroke risk. Each one-unit increase in CTI was associated with a 36% higher hazard of stroke (adjusted HR 1.36, 95% CI 1.18–1.56, p < 0.0001). When categorized into tertiles, participants in the highest CTI tertile had a significantly greater stroke risk than those in the lowest tertile (HR 1.57, 95% CI 1.27–1.95, p < 0.0001), while the middle tertile showed a moderate increase in risk (HR 1.28, 95% CI 1.03–1.58, p = 0.0239). Conclusions: Research has found that elevated CTI at baseline is positive associated with stroke risk. This indicate that the combination of chronic inflammation and insulin resistance – captured by a high CTI – substantially increases the hazard of stroke in individuals with dysglycemia.