Abstract W P143: Race-specific Effects of Inflammatory and Vascular Remodeling Biomarkers in Ischemic Stroke

Abstract

Background: Blacks have a higher risk of stroke than whites; inflammatory and vascular remodeling (VR) biomarkers may mediate this risk. We aimed to determine associations between inflammatory and VR biomarkers and ischemic stroke in a bi-racial sample of the Atherosclerosis Risk In Communities (ARIC) cohort. Methods: In a case-control pilot study, 133 participants from Forsyth and Jackson Field Centers were identified: 32 blacks and 33 whites with first ischemic stroke after visit 2, and 33 black and 35 white stroke-free controls. We assayed IL-8, IL-10, IL-1 receptor antagonist (IL-1ra), IL-1β, matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) with Quantikine ELISA. We calculated IL-1β/IL-1ra ratio, representing the IL-1 pathway. Biomarkers were covariates in race-specific logistic regression models; if significant, biomarker-by-race interactions were explored. Results: Cases were older (mean age 60y vs 56y; p<0.0001); more had hypertension (52% vs 35%; p=0.043), and diabetes (35% vs 13%; p=0.0034). There were no differences in biomarkers between blacks and whites (cases and controls). In blacks, there was a trend toward a reduced risk of stroke with increasing levels of IL-1ra after adjustment (p=0.074). In whites, stroke was associated with higher levels of TIMP-1 (p=0.011; interaction p=0.079) and with higher levels of IL-8 (p=0.011; interaction p=0.11) in the unadjusted, but not adjusted model (Table). Conclusion: We identified race-specific associations between biomarkers and incident stroke. VR biomarkers (TIMP-1) may be associated with stroke in whites, and there was a trend towards lower levels of IL-1ra (counter-inflammatory) and risk of stroke in blacks. Larger studies are warranted to confirm these findings and determine if these markers will explain differences in stroke risk in blacks vs whites.