Cardiovascular Disease Negatively Impacts Cognitive Function
People living with cardiovascular disease (CVD) and type 2 diabetes also live with an elevated risk of cognitive deterioration, according to the results of a new clinical study from Wake Forest Baptist Medical Center. The lead author of this study, Dr. Christina E. Hugenschmidt, suggests that CVD has a significant impact on cognitive function prior to it being clinically apparent in patients.
“There has been a lot of research looking at the links between type 2 diabetes and increased risk for dementia, but this is the first study to look specifically at subclinical CVD and the role it plays,” stated Hugenschmidt. “Our research shows that CVD risk caused by diabetes even before it’s at a clinically treatable level might be bad for your brain.”
“The results imply that additional CVD factors, especially calcified plaque and vascular status, and not diabetes status alone, are major contributors to type 2 diabetes related cognitive decline,” she added.
A Follow Up to the Diabetes Heart Study
Hugenschmidt said that the Diabetes Heart Study-Mind (DHS-Mind) was a follow-up study to the Diabetes Heart Study (DHS), which examined associations between vascular calcified plaque, cognitive function, and other risk factors for diabetes which have been linked to cognition. This diabetes clinical study looked at CVD in family members that had a high rate of type 2 diabetes. Clinical investigators took extensive measurements of CVD risk factors during routine examinations from 1998 to 2006.
The DHS-Mind study combined cognitive testing with existing measures in order to explore the connection between measures of atherosclerosis and cognition in a study group containing a significant number of people who had been diagnosed with diabetes. This was an innovative approach given that other research studies had been focused on diabetes and cognition in the context of clinically evident CVD, according to Hugenschmidt.
Cardiovascular Measures and Type 2 Diabetes
After the diabetes clinical trial was completed, Hugenschmidt’s team followed up on as many of the original 1,443 DHS study participants who had cardiovascular measures as possible (more than 500 study participants). Out of these 516 people, 422 were currently living with type 2 diabetes and only 94 were totally unaffected.
The clinical investigators conducted a battery of cognitive testing that provided a view of different kinds of thinking like memory and processing speed, in addition to executive function. If you are unfamiliar, executive function is a set of mental skills which are coordinated in the frontal lobe of the brain, including stop and think processes such as attention and managing time, organizing, and planning. The ability to observe the data taken from the comparison group with siblings made the results more clinically relevant, as the subjects shared the same genetic and environmental backgrounds.
“We still saw a difference between these two groups. Even compared to their own siblings who were not disease free, those with diabetes and subclinical cardiovascular disease had a higher risk of cognitive dysfunction,” stated Hugenschmidt.
What Can We Learn From CVD?
CVD actually can explain a lot of the cognitive issues affecting people with diabetes, explained Hugenschmidt. “One possibility is that your brain requires a really steady blood flow and it’s possible that the cardiovascular disease that accompanies diabetes might be the main driver behind the cognitive deficits that we see.”
According to Hugenschmidt, clinicians should now consider the risk factors for CVD when they are treating patients who have type 2 diabetes. If this is not done, even the patients who present with borderline clinical levels might suffer from long term complications which could compromise their cognitive health.