Gender and risk factor dependence of cerebral blood flow velocity in Chinese adults.

BACKGROUND AND PURPOSE: The objective of this study is to determine if and how cerebral blood flow velocity and stroke risk factors are related in a stroke free population.

METHODS

This cross-sectional study recruited 1323 stroke-free subjects, aged 42-73 years, from a county region in China. Systolic blood flow velocities in cerebral arteries were detected with trans-cranial Doppler. Key factors, such as anthropometry, life-style, medication use, blood pressure and blood biochemical analysis were investigated at the same time.

RESULTS

In women, even controlled for major cardiovascular risk factors, cerebral blood flow velocities of common carotid artery, internal carotid artery, middle cerebral artery, anterior cerebral artery and posterior cerebral arteries decreased significantly with age (from 43.8 to 39.3, 48.0 to 42.6, 97.7 to 82.8, 79.2 to 69.4 and 44.1 to 39.7 cm/s in the range of 42-73 years old, p < 0.01 for each). In men, however, this inverse trend only existed in common carotid artery (from 45.6 to 41.7 cm/s, p < 0.01). Multivariate regression showed that most established cardiovascular risk factors (e.g. hypertension, hypercholesterolemia, diabetes mellitus and overweight/obesity) were associated with decreased blood flow velocity in the extra-cranial arteries. However, this association was not present (e.g. diabetes and overweight/obesity) or was inversed (e.g. hypertension and hypercholesterolemia) in the intra-cranial arteries.

CONCLUSION

Extra-cranial blood flow velocity is significantly and inversely related to age and cardiovascular risk factors. The relationship between intra-cranial blood flow and risk factors changes and may depend on gender. These finding may have importance in the determination of mechanisms of stroke.