Potential Risk Factors for Stroke

Preliminary studies indicate that activation of the immune system by risk factors for stroke (hypertension, hypercholesterolemia, diabetes and age) increases the risk of atherosclerosis and the formation of intravascular thrombosis. By measuring the levels of cytokine and leukocyte activation in the stroke prone population and age matched controls without risk factors, an attempt will be made to characterize those factors which potentially increase the risk for carotid atherosclerosis and subsequent cerebral infarctions. A total of one hundred twenty subjects with risk factors for stroke and forty controls will be enrolled over a two year period and followed for one year. All subjects will have blood drawn at the time of enrollment, at six months, and one year to measure cytokine levels (including Interleukin-I, Tumor Necrosis Factor-Alpha, Interleukin-8) and leukocyte activation/receptor (including Intercellular Adhesion Molecule-1 (ICAM-1), Endothelial Leukocyte Adhesion Molecule-1 (ELAM-1), V-Cell Adhesion Molecule (VCAM), and Macrophage Antigen-1). Carotid dopplers will be performed at the time of enrollment and at one year. An analysis will be performed to: 1) determine if patients with risk factors for stroke have an increased activation of baseline cytokine levels and leukocytes, 2) determine if patients who have stroke risk factors and are symptomatic have an increased activation of cytokines and leukocyte vs. asymptomatic patients, and 3) determine if patients with increased cytokine/leukocyte activity have accelerated atherosclerosis of the carotid arteries.