The study, which was conducted at the Johns Hopkins University School of Medicine in Baltimore. involved 135 elderly people with newly diagnosed Alzheimer's disease who had annual cognitive tests for an average of three years.
At the beginning of the study, 62 percent of the participants reported one or more of the following vascular factors: irregular heartbeat, high blood pressure, chest pains, coronary artery bypass surgery, heart attack, diabetes, use of medications to treat high blood pressure, and stroke.
According to the study cognitive decline accelerate twice as fast among patients who reported high blood pressure at the time of the Alzheimer's diagnosis as compared to those Alzheimer's patients who did not have high blood pressure. Irregular heartbeats and chest pains due to a lack of blood supply in the heart were also associated with a more rapid decline on cognitive tests.
The researchers also revealed that the Alzheimer's patients who had a history of heart bypass surgery, diabetes, or taking medications to treat high blood pressure had a slower rate of cognitive decline. "The good news is that vascular factors can be modified, so these results may suggest strategies for slowing the progression of Alzheimer's," said study author Michelle Mielke, PhD, with The Johns Hopkins University School of Medicine in Baltimore, MD.
"Many studies suggest that vascular factors are associated with an increased risk of developing Alzheimer's disease; these findings suggest that vascular factors also affect rate of cognitive and functional decline after a diagnosis and further research is clearly warranted. He further said: "Our findings further suggest that medications used to treat high blood pressure may be important in slowing the progression of Alzheimer's once a person is diagnosed.
"However, the findings that show heart bypass surgery and diabetes are associated with a slower rate of cognitive decline are counterintuitive and more research is clearly needed before recommendations can be made."
The study is published in the November 6, 2007, issue of Neurology, the medical journal of the American Academy of Neurology