The follow-up study of blood viscosity in the patients with acute ischemic stroke

Hyperviscosity may be termed the physicochemical risk factor of stroke. The case-control study is designed to clarify whether elevated blood viscosity is causally related to the ischemic event or is associated with the epidemiological risk factors of stroke. A total of 127 patients with acute ischemic stroke were recruited in the study. There were 25 females and 102 males with a mean age 65 ± 10 years (range 46 to 78 years). An equal number of control cases matched with age and sex were selected from healthy volunteers. The fasting blood was taken for the measurement of blood viscosity parameters. The results showed statistically significant differences in plasma viscosity (P<0.01), whole blood viscosity (P < 0.001), erythrocyte aggregability (P<0.001) and fibrinogen level (p < 0.001) between the patients and controls, but no significant difference in RBC deformability and hematocrit. Follow-up studies conducted three weeks (96 cases) and three months (64 cases) later showed that the hyperviscosity phenomenon persisted. We concluded that impairment of blood viscosities are present not only in patients with acute cerebral infarction, but also in those with chronic stage of stroke which may be associated with the risk factors of stroke such as hypertension, diabetes or ischemic heart diseases.