Abstract WP235: Hepatocyte Growth Factor and Risk of Stroke in the Reasons for Geographic and Racial Differences in Stroke Study

Abstract

Introduction: Hepatocyte growth factor (HGF) is a cytokine produced in response to tissue injury and endothelial dysfunction and is correlated with cardiovascular risk factors including hypertension and diabetes. Hypothesis: HGF is associated with risk of stroke, and racial disparities in stroke may be explained by differences in HGF level. Methods: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study enrolled 30,239 black (42%) and white (58%) Americans age 45 and older from 2003-2007. In participants free of baseline stroke, HGF level was measured in a case-cohort study of 534 participants who developed ischemic stroke over 5.4 years and a cohort random sample of 1017 participants. Multivariable linear regression was used to determine correlates of HGF in the cohort random sample. Hazard ratios of stroke by HGF quintile were calculated using Cox proportional hazards models adjusting for stroke risk factors and correlates of HGF. Results: HGF was higher with older age, male sex, cardiovascular disease, smoking, warfarin use and higher CRP, but did not differ by race. Main results are in the figure. Those with HGF in the highest vs. lowest quintile had an HR of incident stroke of 2.12 (CI 1.31-3.41) in the model adjusted for Framingham stroke risk factors. There was no difference in the association by sex or race ( p- interaction > 0.2). As HGF did not differ by race it did not mediate the black-white disparity in stroke incidence. Conclusion: In REGARDS, HGF in the top quintile was associated with a doubling of incident ischemic stroke risk after adjusting for other stroke risk factors. HGF did not mediate the black-white disparity in stroke risk.