Inter‐Relations of Orthostatic Blood Pressure Change, Aortic Stiffness, and Brain Structure and Function in Young Adults

Abstract

BackgroundRelations of orthostatic change in blood pressure with brain structure and function have not been studied thoroughly, particularly in younger, healthier individuals. Elucidation of factors that contribute to early changes in brain integrity may lead to development of interventions that delay or prevent cognitive impairment.Methods and ResultsIn a sample of the Framingham Heart Study Third Generation (N=2119; 53% women; mean age±SD, 47±8 years), we assessed orthostatic change in mean arterial pressure (MAP), aortic stiffness (carotid‐femoral pulse wave velocity), neuropsychological function, and markers of subclinical brain injury on magnetic resonance imaging. Multivariable regression analyses were used to assess relations between orthostatic change in MAP and brain structural and neuropsychological outcomes. Greater orthostatic increase in MAP on standing was related to better Trails B‐A performance among participants aged <49 years (β±SE, 0.062±0.029; P=0.031) and among participants with carotid‐femoral pulse wave velocity <6.9 m/s (β±SE, 0.063±0.026; P=0.016). This relation was not significant among participants who were older or had stiffer aortas. Conversely, greater orthostatic increase in MAP was related to larger total brain volume among older participants (β±SE, 0.065±0.029; P=0.023) and among participants with carotid‐femoral pulse wave velocity ≥6.9 m/s (β±SE, 0.078±0.031; P=0.011).ConclusionsBlunted orthostatic increase in MAP was associated with smaller brain volume among participants who were older or had stiffer aortas and with poorer executive function among persons who were younger or who had more‐elastic aortas. Our findings suggest that the brain is sensitive to orthostatic change in MAP, with results dependent on age and aortic stiffness.

Aortic stiffness, pressure and flow pulsatility, and target organ damage

“…Greater average real variability in ambulatory blood pressure was associated with prevalent cerebral small vessel disease in hypertensive adults (35). A blunted orthostatic increase in MAP was associated with smaller brain volumes and worse executive function, and effects were modulated by age and aortic stiffness in FHS (24). Orthostatic hypotension, greater orthostatic variability in systolic blood pressure (SBP), and blunted heart rate response to orthostasis were associated with increased risk for incident dementia during 15 yr of follow-up in the Rotterdam Study (99).…”

Vascular contributions to cognitive impairment and dementia (VCID): A report from the 2018 National Heart, Lung, and Blood Institute and National Institute of Neurological Disorders and Stroke Workshop

“…Atherosclerosis may adversely impact brain structure and function through multiple pathophysiological mechanisms. The atheroma can directly alter the stiffness of the aorta and cerebral vasculature; arterial stiffness assessed as carotid‐femoral pulse wave velocity has been associated with smaller brain volumes, increased volume of abnormal white matter, and microstructural injury within apparently normal looking white matter 107,112‐114 . It could also impair cerebral circulation at rest or under stress even at subclinical degrees of carotid stenosis 115 .…”

Orthostatic hypotension as a risk factor for longitudinal deterioration of cognitive function in the elderly

“…The prevalence of OH increases with aging with about 20%–30% of people aged 65 or older being affected . Reasons for OH are, amongst others, a reduced baroreceptor sensitivity, a reduced activity of the sympathetic nervous system , aortic stiffness and cardiovascular diseases or other conditions causing a decrease in cardiac output. Several studies report a bidirectional interaction of OH with multimorbidity in elderly people comprising hypertension, coronary heart disease and a higher risk for strokes , promoting cognitive dysfunction, falls and all‐cause mortality .…”