Vascular diseases after age 80 is associated with a greater risk of dementia, as is simply living longer, according to new research out of the University of Pittsburgh Graduate School of Public Health.
In a small group of participants, the researchers found an association between zero or low levels of artery-clogging calcium deposits and a low risk of dementia and cardiovascular events, suggesting that the cardiovascular risk factors that lead to coronary heart disease could also affect the brain. Increasingly, successful heart disease prevention and treatment methods have also led to longer lifespans, which in turn creates a larger population of older people at risk for dementia, according to the research published in the Journal of the American College of Cardiology.
“If delay or prevention of atherosclerosis resulted in the reduction or slowing of progression of brain disease and subsequent incidence of dementia, then there is the potential for a very substantial impact on reducing the majority of dementia in very old ages,” said Lewis H. Kuller, M.D., Dr.P.H., lead author of the study and emeritus professor in Pitt Public Health’s Department of Epidemiology. “There is a need to test such hypotheses by substantially modifying risk factors, slowing the progression of atherosclerosis and determining whether such an effect will substantially reduce the incidence of dementia and specific neuropathology among older patients.”In the U.S., dementia mainly affects people over the age of 75. Dr. Kuller and his team looked at people over age 80 to determine if coronary artery calcium levels predict risk of death and risk of dementia and coronary heart disease.
Beginning in 1998, 532 participants from the Cardiovascular Health Study-Cognition Study were evaluated annually through 2013 for signs of dementia. Measurements were also taken of coronary artery calcium deposits, which can narrow arteries and increase heart attack risk.
People with coronary artery calcium levels of zero showed signs of dementia on average just over seven years from the initial measurement versus an average of just over five years for those with coronary artery calcium scores over 400, which is the highest level.
According to Dr. Kuller, these results suggest several scenarios. The first is that the prevalence of dementia in older populations will likely increase as prevention and treatment of coronary heart disease improve and increase the longevity of the general population.
“As age at first heart attack continues to rise, dementia will be an important comorbidity and will affect treatment decisions and outcomes,” Dr. Kuller.
A second scenario is that a zero or very low coronary artery calcium score is associated with a low risk of dementia but because of the small sample size these results need to be replicated in other studies of the elderly.
A third scenario is that cardiovascular risk factors such as high blood pressure, diabetes, smoking and not exercising that lead to the development of atherosclerosis and eventually coronary heart disease could also affect progression of brain pathology, such as the risk of dementia.