In the Grips of Angst: Investigating the Associations of Anxiety, Blood Pressure, and Cerebral Perfusion Among Older Adults

Abstract

As the world’s population continues to age, brain health research must explore the biopsychosocial determinants of brain aging and subsequent impacts to quality of life among the elderly. One age-related indicator of brain health is cerebral blood flow (CBF), or the blood flow through neural tissues, that naturally decreases with age. Anxiety disorders and hypertension are well-known factors that contribute not only to disease burden and mortality among older adults but have also been demonstrated to correlate with CBF measures; however little is known about the role of trait anxiety. Thus, the examination of the potential synergistic associations of these variables with CBF in older adults may provide insight into differential aging trajectories and elucidate the influence of psychological emotion on biomedical indices known to impact aging. This study examined the potential interactive relations of trait anxiety and resting blood pressure (both systolic and diastolic) to single-photon emission computerized tomography (SPECT)-derived CBF measurements among a sample of older adults. Participants included 91 (mean age = 66.74, % female = 64, 13% ethnic minority) older adults enrolled in a research study on cardiovascular risk factors, neurocognitive function, and neuroimaging. Trait anxiety was assessed using the trait subscale of Spielberger’s State-Trait Personality Inventory (STPI). Using model deconstruction, multivariable regression analyses were conducted to examine the interactive and independent associations of trait anxiety and blood pressure to CBF in cortical regions. Sensitivity analyses were conducted to determine if significant findings withstood statistical adjustments for associated variables. Contrary to our hypotheses, results revealed no significant interactions of trait anxiety and blood pressure, or main effects of trait anxiety to CBF. However, backwards elimination revealed significant main effects of blood pressure to CBF (seven for diastolic and three for systolic blood pressure) across various cortical regions such that increased blood pressure predicted decreased CBF. This lack of confirmation of our hypotheses may, in part, be explained by inadequate measurement of a full spectrum of anxiety symptoms and disorders. Future work should seek to better capture the various elements of anxiety (i.e. somatic complaints versus personality features) via composite variables, or seek to better compare these differing scales using statistical approaches. The study’s identification of significant associations of blood pressure and CBF in the context of this sample’s relatively controlled blood pressure levels, suggests that moderate increases in blood pressure are associated with dysregulation of CBF. These findings underscore the need for close monitoring of blood pressure in older adults and suggests intervention at moderate elevations may protect cerebrovascular homeostasis. This may provide valuable information for health care providers in monitoring and preventing cerebrovascular-related brain injury among geriatric patients and inform public health initiatives targeting cardiovascular health into older age.