BRAIN METABOLIC FUNCTION IN OLDER MEN WITH CHRONIC ESSENTIAL-HYPERTENSION

Background and Methods. To determine the effects of hypertension on br ain function, positron emission tomography (PET) studies using (18F)-2 -fluoro-2-deoxy-D-glucose (FDG) were performed on a group of 17 otherw ise healthy older hypertensive men (mean age +/- SD = 69 +/- 8 yr) and 25 age- and gender-matched controls. Subjects had medically treated e ssential hypertension for a minimum of 10 years (range = 10 to 24 yr) with no evidence of end-organ impairment from hypertension by routine clinical screening and by history. All hypertensive and control subjec ts were determined to be cognitively normal by extensive neuropsycholo gical testing. The hypertensive subjects previously had been reported to have lateral ventricle enlargement and left hemisphere brain atroph y by quantitative MRI. PET data were analyzed using t-tests to look at group differences. Results. The hypertensive subjects were found to h ave reduced brain glucose utilization in 36/37 regions-of-interest (RO Is). The differences were significant (p < .05) in 10 (27%) of the reg ions. The thalamic and lenticular nuclei were affected bilaterally. Gl obal values did not significantly differ between groups. Conclusions. Our findings suggest that brain morphologic changes in longstanding, t reated hypertension are accompanied by subtle changes in cerebral gluc ose metabolism. Whereas the changes were most prominent in the subcort ical nuclei, there was a strong trend toward hypometabolism throughout the cortex. We speculate that these changes represent early target or gan damage in brain regions vulnerable to the effects of chronic hyper tension.