Type 2 diabetes and other metabolic risk factors may contribute to cognitive decline

Type 2 diabetes, high blood pressure, smoking and obesity may significantly increase a person’s chances of developing cognitive problems later in life, according to a new study out of the University of California, Davis.

The findings, which were published in the journal Neurology, could have important implications, as the overall prevalence of cognitive problems like Alzheimer’s disease is rising rapidly. Additionally, the condition appears to be becoming more common in response to rising rates of obesity, which is the single most common cause of type 2 diabetes.

For the study, researchers analyzed 1,352 individuals over the course of a decade. The researchers took measures including body mass index, blood pressure, cholesterol and blood sugar. Participants also answered lifestyle questions, including whether or not they smoked. Throughout the course of the study, the researchers took MRI scans of the participants.

The results showed that those who had high blood pressure, smoked cigarettes, were obese or had type 2 diabetes were significantly more likely to show signs of neurodegeneration known as hyperintensities. These are areas of blood vessel damage in the brain that are associated with cognitive decline.

Additionally, these participants had lower brain volumes and showed more signs of cognitive decline by the end of the investigation.

"These factors appeared to cause the brain to lose volume, to develop lesions secondary to presumed vascular injury and also appeared to affect its ability to plan and make decisions as quickly as 10 years later,” said Charles DeCarli, MD, the leader of the study.

Furthermore, he added that medical professionals should consider beginning to use factors like type 2 diabetes and high blood pressure to identify patients who are at the greatest risk of developing cognitive problems. Early diagnosis and treatment can lead to better outcomes for people with conditions like Alzheimer’s disease and for some, it may even be possible to avoid cognitive problems.

"Our findings provide evidence that identifying these risk factors early in people of middle age could be useful in screening people for at-risk dementia and encouraging people to make changes to their lifestyle before it's too late," DeCarli added

Over the past 20 to 30 years, rates of Alzheimer’s disease have risen dramatically. The Alzheimer’s Association says that death rates from the cognitive problem increased by 66 percent between 2000 and 2008, even while death rates for most other health conditions declined. Similarly, diabetes rates have more than doubled since the 1980s.

The present study suggests that these trends may not be a coincidence. The fact that metabolic problems influence cognitive health could bring a new understanding to maintaining mental capacity into old age.

For many people, losing their cognitive abilities is among their most serious concerns associated with getting older. However, the new study suggests that taking steps to reduce type 2 diabetes risk may be among the most important things a person can do for their mental health.