Factors known to increase risk for heart disease during middle age – diabetes, high blood pressure and smoking – also raise the risk of dementias such as Alzheimer’s disease later in life. So concludes a study presented at the American Stroke Association’s International Stroke Conference 2017, held Feb. 22-24, in Houston, Texas.
“The health of your vascular system in midlife is really important to the health of your brain when you are older,” Rebecca F. Gottesman, MD, Ph.D, the study’s lead researcher, said in a press release.
The results are part of an ongoing study, which began in 1987 and included 15,744 participants from four U.S. communities. As dementia increased with age, those 45 to 64 years old at risk of heart disease also showed increased risks for dementia.
A total of 1,516 participants developed dementia during the study, but those who had been midlife smokers were 41 percent more likely than non-smokers to get dementia. Other significant contributors to dementia risk were diabetes in middle age (77 percent increased risk) and high blood pressure (39 percent higher).
In fact, “diabetes raises the risk almost as much as the most important known genetic risk factor for Alzheimer’s disease,” said Gottesman, who is also an associate professor of neurology and epidemiology at Baltimore’s Johns Hopkins University.
Researchers also found some gender and racial risk disparities. Men were 11 percent more likely than women to have dementia. Other groups at risk: blacks, those without at least a high-school education, and people genetically predisposed to Alzheimer’s. However, smoking and genetic risk to Alzheimer’s were especially strong dementia risk factors among whites.
“If you knew you carried the gene increasing Alzheimer’s risk, you would know you were predisposed to dementia, but people don’t necessarily think of heart disease risks in the same way,” said Gottesman. “If you want to protect your brain as you get older, stop smoking, watch your weight, and go to the doctor so diabetes and high blood pressure can be detected and treated.”
The current study, however, hasn’t addressed whether therapies lowering heart risk factors also decrease the risk for dementia later in life. However, as Gottesman said, “The benefit is that this is a long-term study and we know a lot about these people. Data like these may supplement data from clinical trials that look at the impact of treatment for heart disease risks.”