Background and purpose: Cardiovascular disease risk predicts cognitive decline although the mechanisms underpinning this association remain unclear. Increasing cardiovascular risk may impair cerebral blood flow predisposing to cerebrovascular damage, cognitive decline, and dementia.
Methods: This study examined the association between the Framingham General Cardiovascular Risk Profile and cerebral blood flow velocity in 160 healthy middle-aged adults. Blood flow velocity was assessed in both the common carotid and middle cerebral arteries using Doppler.
Results: In adjusted linear regression models, cardiovascular risk predicted higher pulsatile (common carotid artery β=0.56, ΔR(2)=0.19, P<0.001; middle cerebral artery β=0.40, ΔR(2)=0.09, P<0.001) and lower mean flow velocity (common carotid artery β=-0.49, ΔR(2)=0.14, P<0.001; middle cerebral artery β=-0.27, ΔR(2)=0.04, P<0.05). Cardiovascular risk predicted common carotid artery mean and pulsatile flow over and above the effects of age (ΔR(2)=0.11-0.19, P<0.001) and sex (ΔR(2)=0.03-0.03, P<0.05). In contrast, cardiovascular risk remained a significant predictor of middle cerebral artery pulsatile, but not mean flow velocity, when controlling for age (ΔR(2)=0.05, P<0.05) and sex (ΔR(2)=0.06, P<0.01).
Conclusions: Cardiovascular risk has divergent effects on mean and pulsatile blood flow velocity, each of which may independently contribute to cerebral pathology and cognitive impairment.