Aorta‐carotid hemodynamics and cognitive function in the U.S. POINTER Neurovascular ancillary study
Tina E Brinkley, Gary F Mitchell, Katelyn R Garcia, Xiaoyan Leng, Charles H Tegeler, Laura D Baker, Heather M Snyder, Margie J Bailey, Hossam A Shaltout- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
The brain is particularly sensitive to excessive pressure and flow pulsatility. Disproportionate stiffening of the aorta can reduce wave reflection at the aorta‐carotid interface and facilitate transmission of excessive pulsatile energy into the cerebral microcirculation, leading to impaired cognitive function. The U.S. POINTER Neurovascular (POINTER‐NV) ancillary study is an ongoing study designed to evaluate vascular structure and function in participants from the U.S. POINTER trial. Here we describe the baseline characteristics of the POINTER‐NV participants, focusing on aortic and carotid variables and their association with cognitive function.
Method
Ultrasound and tonometry were used to assess aortic and carotid measures. Hemodynamic and structural variables were compared according to cognitive status using the baseline Clinical Dementia Rating Scale Sum of Boxes (CDR‐SB) score categorized as normal (CDR‐SB = 0) or possibly impaired (CDR‐SB>0). Linear regression was used to assess cross‐sectional associations between aortic and carotid variables and composite scores for global cognition, executive function, memory, and processing speed, with and without adjustment for age, sex, race, and ethnicity.
Result
Aortic and carotid hemodynamics were available for 165 POINTER‐NV participants (mean age: 67.9±5.1 years, 70% female, 37% people of color). A large proportion of the participants had evidence of subclinical cardiovascular disease based on a carotid intima‐media thickness ≥1.0 mm (n = 109/165, 66.1%) or increased aortic stiffness based on a carotid‐femoral pulse wave velocity >10 m/s (n = 70/131, 53.4%). There were no significant differences in aortic or carotid structure and function between participants with normal cognition (n = 109) and those with possible cognitive impairment (n = 56). Higher carotid‐femoral pulse wave velocity was associated with lower global cognition, executive function, and processing speed, even after adjustment for age, sex, race, and ethnicity (all p<0.05). Although there was some suggestion that higher carotid pulsatility, higher carotid transmission, and lower aorta‐carotid reflection may be associated with worse cognition, these associations were not consistent across cognitive domains and did not hold up after covariate adjustment.
Conclusion
Age‐related changes in vascular structure and function can promote cognitive decline and dementia. Our data are consistent with prior evidence suggesting that higher aortic stiffness may be particularly important in this regard.