on March 9, 2009
Published online before print March 9, 2009, doi: 10.1161/HYPERTENSIONAHA.108.126227
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Submitted on November 17, 2008
From the Department of Psychiatry (P.J.G., L.K.S., A.M.R., I.C.C.), University of Pittsburgh, Pa; Department of Psychiatry (H.D.C.), Brighton and Sussex Medical School, University of Sussex Campus, Falmer, Brighton, United Kingdom; and the Center for Functional Neuroimaging (J.W.), University of Pennsylvania, Philadelphia. * To whom correspondence should be addressed. E-mail: gianarospj{at}upmc.edu.
Abstract—Individuals who express relatively large-magnitude or "exaggerated" blood pressure (BP) reactions to behavioral stressors are presumably at increased risk for cardiovascular disease. As shown by recent neuroimaging studies, individuals who express exaggerated stressor-evoked BP reactivity also express heightened neural activity in corticolimbic brain areas that centrally regulate the cardiovascular system. These studies, however, have exclusively examined BP reactivity and concomitant neural activity during stressor exposure. If exaggerated BP reactivity originates in part from a centrally regulated and dispositional cardiovascular response tendency, then heightened resting (prestressor) corticolimbic activity may predict the subsequent expression of exaggerated stressor-evoked BP reactivity. To test this hypothesis, perfusion MRI was used to quantify resting regional cerebral blood flow (an indirect metabolic measure of neural activity) in men (n=19) and women (n=20) aged 20 to 37 years who subsequently performed cognitive stressor tasks to evoke BP reactivity. Individuals who expressed larger task-induced rises in systolic and diastolic BP also expressed higher resting regional cerebral blood flow in 4 functionally related corticolimbic areas: the dorsal and perigenual anterior cingulate, medial prefrontal, and insular cortices. Specifically, resting regional cerebral blood flow in these areas accounted, respectively, for 40% and 31% of the variance in systolic (P=0.001) and diastolic (P=0.008) BP reactivity, after accounting for total resting cerebral blood flow, resting BP, task performance, and task-related ratings of unpleasantness, arousal, and perceived psychological control. Heightened resting corticolimbic activity may represent a neurobiological correlate of an individual's predisposition for exaggerated stressor-evoked BP reactivity and possibly related cardiovascular risk.
Revised on December 9, 2008
Heightened Resting Neural Activity Predicts Exaggerated Stressor-Evoked Blood Pressure Reactivity
Peter J. Gianaros*;
Key words: anterior cingulate cortex • blood pressure reactivity • individual differences • insula • medial prefrontal cortex • stress