Diabetes, hypertension and erythrocyte aggregation in acute stroke

Elevated erythrocyte (RBC) aggregation (RBC-A) may contribute to the pathogenesis of stroke and stroke recurrence. We measured RBC-A at low shear in 55 patients with acute ischemic stroke and in 24 age-balanced controls without cerebrovascular disease or vascular risk factors. RBC-A was significantly elevated in subgroups of stroke patients who were hypertensive, diabetic, or both, compared with either stroke patients lacking these risk factors (p at least <0.01) or healthy elderly (all p < 0.001). RBC-A was normal in stroke patients (n = 14) free of both diabetes and hypertension. In a multivariate linear regression model glycosylated hemoglobin (p < 0.0001), plasma viscosity (p < 0.006) and systolic blood pressure (p < 0.05) were each independently significant and together accounted for about 52% of the variation in RBC-A in acute stroke patients. No relationship was detected between RBC-A and infarct size or among the major subtypes of ischemic stroke. The results suggest that vigorous control of both blood glucose and blood pressure may reduce the potentially damaging effects of elevated RBC-A in the cerebral vasculature.