31 Mar Brain Amyloid Deposition Strongly Related to Arterial Stiffness
MedicalResearch.com Interview Invitation with:
Timothy Hughes, PhD, MPH
Roena B. Kulynych Center for Memory & Cognition Research
Department of Internal Medicine
Division of Gerontology and Geriatric Medicine
Wake Forest School of Medicine
Medical Center Boulevard, Winston-Salem, NC 27157-1207
MedicalResearch.com: What are the main findings of the study?
Dr. Hughes: This study is a follow-up to our recent paper that showed a novel relationship between arterial stiffness (commonly measured by pulse wave velocity) and the presence and extent of amyloid deposition in the brain, a hallmark of Alzheimer’s disease. For this study, we repeated brain amyloid imaging (using the Pittsburgh Compound B during PET imaging) in order to look for predictors of change in amyloid over two years in n=81 elderly adults aged 80+ and free from dementia. We observed that measures of systemic arterial stiffness (e.g. brachial ankle pulse wave velocity) was strongly associated with the extent of amyloid deposition in the brain at both baseline and follow-up. The change in brain amyloid accumulation over two years resulted in an increase in in the number of participants with Alzheimer’s-like (amyloid-positive) from 45% at baseline to a surprising 75% after just two years. This change in brain amyloid accumulation over two years was strongly related to having greater central stiffness (as measured by carotid femoral pulse wave velocity). These relationships between arterial stiffness and brain amyloid deposition were independent of the effects of age, gender, body mass index, antihypertensive medication use and even current blood pressure.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Hughes: The amount of amyloid deposition in the brain of these elderly participant free from dementia provides more evidence that brain amyloid deposition is a common feature in brain aging and not just in the development of Alzheimer’s disease. The increase was from 45% at baseline to 75% after just two years. Also given the myriad of factors that can contribute to amyloid deposition in the brain, we saw surprisingly strong and robust relationships between peripheral arterial stiffness and brain amyloid deposition.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Hughes: Amyloid plaque builds up with age and appears to worsen in those with stiffer arteries. Arterial stiffness maybe a strong indicator of several aspects of brain health including cerebrovascular disease and now amyloid plaque deposition. Currently we have no way to prevent amyloid plaque formation and deposition in the brain. Finding and preventing the causes of Amyloid plaque buildup is going to be an essential factor in the prevention Alzheimer’s disease and extending brain health throughout life.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Hughes: As we age, increasing central stiffness results mainly from a loss of elastin in the central arteries. Stiff central arteries transmit more pulsatile pressure deeper into the arterial tree that damages the delicate microvasculature of the brain and kidneys, not to mention its effect on the heart. There is hope that current antihypertensive medications will prevent dementia and age-related cognitive decline. However, current antihypertensive medications do not directly treat or reverse the problem of central stiffness, which is likely to driving factor in the damage to kidneys, lungs and brain often attributed to hypertension.
Timothy M. Hughes PhD, MPH, Lewis H. Kuller MD, DrPH, Emma J. M. Barinas-Mitchell PhD, Eric M. McDade DO, William E. Klunk MD, PhD, Ann D. Cohen PhD, Chester A. Mathis PhD, Steven T. DeKosky MD, Julie C. Price PhD, Oscar L. Lopez MD