Relationships of transcranial blood flow Doppler parameters with major vascular risk factors: TCD study in patients with a recent TIA or nondisabling ischemic stroke

PURPOSE: The relationship between intracranial vascular disease and cardiovascular risk factors such as smoking, hypertension, diabetes mellitus, and total serum cholesterol in patients with recent cerebral ischemia is not well established. We used transcranial Doppler (TCD) sonography tests as parameters of intracranial vascular disease and investigated the relationship between these parameters and conventional cardiovascular risk factors. METHODS: We prospectively studied 598 patients with a minor ischemic stroke or transient ischemic attack (TIA). In all patients, flow velocities in the left and right middle cerebral artery (MCA), and cerebrovascular reactivity to CO2 were measured by means of TCD sonography. Student's t-test and linear regression analysis were used to determine the relationship between the baseline characteristics, vascular risk factors, and TCD parameters. RESULTS: After adjustment for other vascular risk factors, a statistically significant relationship with mean flow velocity in the MCA was found for age (3.5 cm/s/10 years of age; 95% CI, 2.5-4.5 cm/s/10 years of age; p < 0.0001), sex (-2.9 cm/s for male sex; 95% CI, -5.5 to -0.3 cm/s; p = 0.03), diabetes (5.6 cm/s for diabetics; 95% CI, 2.1-9.1 cm/s; p = 0.002), and total serum cholesterol (2.4 cm/s per mmol increase in total serum cholesterol; 95% CI, 1.4-3.5 cm/s; p < 0.0001). Total serum cholesterol and hypertension were related to cerebrovascular reactivity to CO2. CONCLUSIONS: Cerebral flow velocity is influenced by multiple interacting factors. Results of TCD investigations should be adjusted for age, sex, diabetes, and cholesterol when used for diagnostic or prognostic purposes.