The same risk factors for heart attack and stroke—hypertension, diabetes, and smoking—were linked to a higher risk of developing dementia later in life when compared to those in better cardiovascular health at mid-life. Those are the findings of a new study published in JAMA Neurology.
But, the researchers also found that prehypertension— elevated blood pressure that is not high enough to categorize as high blood pressure, yet still higher than normal—puts people at risk for the neurological disease.
For the study, Rebecca Gottesman, M.D., Ph.D., professor of neurology at Johns Hopkins University in Baltimore, and her team analyzed data of 15,744 people who participated in the Atherosclerosis Risk in Communities (ARIC) study.
The ARIC study, funded by the NIH’s National Heart, Lung, and Blood Institute, provided initial medical exams to participants upon enrollment from 1987 to 1989, then followed up with the study population four more times over the next 25 years. Cognitive tests were administered all but the first and third exams.
Among the 1,516 participants diagnosed with dementia, the chances increased most strongly with age followed by the presence of APOE4, a gene associated with Alzheimer’s disease. Researchers reported whites with one copy of the APOE4 gene had a greater chance of dementia than blacks. Other factors included race and education: blacks had higher chance of dementia than whites; those who did not graduate from high school were also at higher risk.
Like previous studies, researchers found people with diabetes or hypertension had a higher chance of developing dementia. Diabetes was almost as strong a predictor as the presence of the APOE4 gene.
However, unlike previous studies, the researchers noticed a link between dementia and prehypertension. Those with hypertension in midlife had a 39 percent chance of developing dementia, while the risk was 31 percent for those with prehypertension. Race did not influence the association—both white and black participants showed an increased risk.
“Our results contribute to a growing body of evidence linking midlife vascular health to dementia,” said Gottesman. “These are modifiable risk factors. Our hope is that by addressing these types of factors early, people can reduce the chances that they will suffer from dementia later in life.”
She said her team will continue to investigate how these vascular problems influence the brain and why race is associated with dementia.
“With an aging population, dementia is becoming a greater health concern. This study supports the importance of controlling vascular risk factors like high blood pressure early in life in an effort to prevent dementia as we age,” said Walter J. Koroshetz, M.D., director of NIH’s National Institute of Neurological Disorders and Stroke (NINDS), which partially funded the study and created the Mind Your Risks public health campaign to make people more aware of the link between cardiovascular and brain health.
He added: “What’s good for the heart is good for the brain.”