Hypertension and Vascular Contributors to Cognitive Disorders
Our research focuses on the impact of hypertension on aging and brain health. We are studying the impact of blood pressure and changes that occur within the vascular system in hypertension including arterial stiffness and endothelial markers on cognitive function, cerebral perfusion and other neuroimaging changes. We are collaborating with a team of investigators at Emory to investigate vascular molecular triggers and markers of these relations including genetic, epigenetic, proteomic, and metabolomics changes that can improve our ability to identify those at risk for developing cognitive impairment and Alzheimer’s disease. We are also studying the changes that occur in the peripheral and central vascular system in hypertension and in Alzheimer’s disease.
Antihypertensive Medications for Cognitive Disorders
As part of our goal to identify new therapies for cognitive loss and Alzheimer’s disease, we are studying the use of antihypertensive medications to prevent cognitive loss with aging, hypertension and Mild Cognitive Impairment (MCI) potentially a pre-dementia stage of Alzheimer’s disease. In particular, we are focusing on the drugs that inhibit the renin angiotensin system, which is intimately involved in hypertension. Our work and others have suggested an important role of this system in brain health and Alzheimer’s disease.
We therefore are conducting studies that test if blocking this system would offer protection against cognitive loss in hypertension or in early stages of Alzheimer’s.
Microvascular Function, Progenitor Cells, and Cognition
Progenitor cells (previously termed endothelial progenitor cells) are mononuclear cells with a specific expression of surface antigens. Progenitor cells are involved in vascular regeneration. A reduction in these cells may be linked to poor heart and vascular health. We are studying the role of these cells in cognitive decline and the development of cognitive disorders such as Alzheimer’s disease. We are also investigating the role of vascular function by measuring arterial stiffness, peripheral and cerebral endothelial and microvascular function.
Stress Racial Disparity and the Heart-Brain Connection
It is well known that hypertension in more prevalent in African Americans especially those residing in the southeastern US. Hypertension in African Americans is:
- More common
- Starts at an earlier age
- For the same age, BP levels are higher
- For the same BP level, more damaging
Our analysis of the NHANES data has identified that African Americans with hypertension have the highest rate of subjective memory loss and physical limitations and that these subjective symptoms predict a higher mortality in African Americans. Racial disparity in Risk of memory loss:
- The risk of memory loss (10%) is higher in African Americans than any other race (7% in Whites and 7% in Mexican Americans)
- For the same BP level, the number of people reporting memory loss is also highest.
In this area of our work, our objective is to identify factors that might explain these disparities. We are currently focusing on social stress and discrimination experiences as a potential factor in the cognitive and vascular disparities.