Abstract 81: Circulating Interleukin-6 Levels Associate With Risk Of First-ever Cerebrovascular Events In Patients With Cardiovascular Risk Factors
Background and objective: Relations between inflammatory marker levels and future stroke have been recently shown, but it remains unclear how these measurements could be combined with established surrogate-markers for stroke, carotid intima-media thickness (IMT) and silent lacunar infarction (SLI) for prediction. The purpose of this study is to clarify whether inflammatory marker levels are associated with cerebrovascular events (CVEs) independent of IMT and SLI
Methods: We enrolled 464 outpatients who had cardiovascular risk factors without any preexisting cardiovascular disease (CVD). We examined the presence of SLI by MRI; evaluated IMT by ultrasound; and measured high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, and IL-18 at baseline and assessed their associations with CVEs using Cox proportional hazards models. We further calculated measures of reclassification and discrimination.
Results: During 4.8±2.6 years of follow-up, CVEs occurred in 25 patients. In age- and sex-adjusted analysis, IL-6, but neither hsCRP nor IL-18, was associated with CVEs. The association remained significant after adjustment for conventional risk factors, IMT, and SLI (hazard ratios (HR):1.80, [95% CI: 1.06-3.08], per 1-SD increase in log IL-6, p=0.03). Compared to the patients with below median IL-6 without SLI, those with above median IL-6 and SLI had a higher risk of CVEs (HR: 4.14, [1.31-15.73], p=0.0014). The combination of IL-6 and SLI resulted in the net reclassification improvement of 14.3% (p=0.04), and the integrated discrimination improvement gain of 2.1% (p=0.05).
Conclusion: IL-6 levels improved CVEs risk stratification in patients with cardiovascular risk factors without prior CVD. Further large investigations will be needed to assess whether risk refinements measuring IL-6 levels lead to a meaningful change in clinical cerebrovascular events.
- © 2012 by American Heart Association, Inc.