Reduced cerebral blood flow in older men with higher levels of blood pressure

Objective: To examine relations of blood pressure (BP) with single photon emission computed tomography (SPECT)-derived estimates of cerebral blood flow in older men and women. Methods: Seventy-four stroke and dementia-free, community-dwelling older adults (ages 54-83 years; 68% men; 91% white) free of major medical, neurological, or psychiatric disease, engaged in clinical assessment of resting SBP and DBP, MRI rated for brain atrophy, and brain single photon emission computed tomography (SPECT) studies with computerized coding of cortical and select subcortical regions of interest. Results: Given significant interactions of BP and sex with respect to multiple SPECT outcomes, sex-stratified multiple regression models were computed. Models were adjusted for age, fasting glucose levels, antihypertensive medication, BMI, and MRI ratings of brain atrophy. In men (n = 50), higher levels of SBP and/or DBP were associated significantly with lower estimates of cerebral perfusion in the right and left frontal, temporal, parietal, and occipital cortex, thalamus, head of caudate, and cingulate cortex accounting for up to 28% of the variance in these measures (P < 0.05). In women (n = 24), higher DBP was related marginally to higher levels of perfusion in the right temporal cortex (P = 0.05). Conclusion: Higher resting SBP or DBP was associated with lower levels of cerebral perfusion in otherwise healthy older men, but not women, in the present sample. Reduced cerebral blood flow may play a pathogenic role in increasing risk for stroke, dementia, and/or cognitive decline, particularly among older men with high BP.