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.

Peripheral arterial disease and cognitive function.

OBJECTIVE: Peripheral arterial disease (PAD) is associated with comorbid atherosclerosis of the coronary and carotid arteries and is a significant risk factor for stroke. However, cognitive function in PAD patients before clinically evident stroke remains poorly characterized. Here we hypothesized that, on neuropsychological testing, PAD patients would perform more poorly than healthy control subjects, and persons with mild cardiovascular disease (essential hypertension), but better than stroke patients, thus reflecting a continuum of cognitive impairment associated with increased severity of vascular disease. METHOD: The cognitive performance of 38 PAD patients (mean ankle-brachial index=0.67, Fontaine Class II) was contrasted with that of 23 healthy normotensive controls, 20 essential hypertensives, and 26 anterior ischemic stroke patients on twelve neuropsychological tests. RESULTS: PAD patients performed significantly more poorly than hypertensives and normotensives, but better than stroke patients, on seven tests of nonverbal memory, concentration, executive function, perceptuo-motor speed, and manual dexterity. Hypertensives displayed poorer performance than normotensives on tests of nonverbal memory and manual dexterity. These findings were independent of age, education, and depression scores. Higher diastolic blood pressure and plasma glucose levels predicted poorer performance of select cognitive tests by PAD patients. Eight to 67% of PAD patients displayed impaired performance (< 5(th) percentile of normotensive controls) on the seven aforementioned cognitive tests. CONCLUSIONS: PAD patients exhibit diminished performance across a variety of domains of cognitive function. Findings also suggest a continuum of cognitive impairment associated with increasingly severe manifestations of cardiovascular disease, thus emphasizing the need for enhanced preventative measures to avert functional declines.

Cerebral blood flow and anxiety in older men: an analysis of resting anterior asymmetry and prefrontal regions.

Asymmetric resting blood flow in prefrontal and hemispheric regions, assessed by single photon emission computed tomography (SPECT), was examined as a potential biological marker for enhanced trait and state anxiety in 30 older men (ages 55-81). Average and asymmetric perfusion in dorsolateral, medial, and orbital regions of the prefrontal lobes was also assessed. Results indicated a significant association between lower levels of resting dorsolateral blood flow and greater state anxiety responses to a series of stressful provocations (measured on a separate occasion). A significant curvilinear (U-shaped) relation between asymmetric dorsolateral perfusion and state anxiety was also identified; increased asymmetric blood flow favoring either the right or the left dorsolateral region related to higher levels of state anxiety. However, this association was attenuated by age and systolic blood pressure. Resting perfusion in the dorsolateral region may represent a more reliable biological marker for state anxiety than trait anxiety in older men.