A new report from the Framingham published in the August 2 edition of Circulation shows that decreased cardiac function is correlated with increased risk of dementia.
"Generally speaking, it seems that heart and brain health are related, so proper management of cardiovascular risk factors may have important implications on brain health," says Angela Jefferson, PhD, from the Boston University School of Medicine in Massachusetts.
Using Framingham data, the researchers looked at 1504 participants free of clinical stroke, transient ischemic attack, or dementia. They reviewed brain and cardiac magnetic resonance images and neuropsychological and laboratory data. They found that cardiac index (a measure of heart health) was positively related to total brain volume and information processing speed but was inversely related to lateral ventricular volume. Data revealed that participants with the lowest and middle cardiac indices had significantly lower brain volumes than participants with the best cardiac indices.
In an accompanying editorial, Clinton Wright, MD, and Ralph Sacco, MD, from the University of Miami in Florida, suggest the finding that even intermediate reductions in cardiac index were associated with declines in brain volume is striking.
The mechanism for associations between cardiac index and evidence of brain aging is unknown. However, the study authors suggest reduced systemic blood flow may contribute to subclinical brain injury because of its impact on cerebral blood flow homeostasis. In other words, poor heart function may injure the brain long-term.
"It will take years to know the fate of all 1504 Framingham participants," the editorialists add. "Whether lower cardiac index leads to reduced brain volumes and accelerates neurodegeneration on an eventual path to dementia is not yet clear. What is known is that various vascular risk factors, including decrements in cardiac function, are determinants of dementia — both Alzheimer disease and variants of vascular dementia. This provides opportunities to find interventions that modify the course of these diseases predicted to be of major impact on our aging population."
Bottom line: use that gym membership.