Worldwide, 387 million people are living with diabetes with numbers expected to increase to 592 million in the next twenty years. If left unmanaged, diabetes can have serious effects on the heart, kidneys, nerves and teeth and puts the individual at an increased risk of stroke and dementia. Now, a new study has found further evidence of diabetes’ impact on brain health by reducing blood flow to the brain and causing cognitive decline in older adults.
Vera Novak, MD, PhD, associate professor of neurology at Harvard Medical School and Beth Israel Deaconess Medical Center, and her colleagues studied sixty-five participants, aged 57-75 years old, for two years – about half of the participants had type 2 diabetes. MRI scans and blood tests monitored inflammation and blood flow in the brain and tests evaluated cognitive functioning of the participants over the two-year span.
The research group found that participants with diabetes had greater declines in gray matter volume and rates of blood flow to the brain. The diabetic group also performed worse than the non-diabetic group on cognitive tests assessing their daily living functions and executive function, or higher-level thinking that includes reasoning, problem solving, judgment and cognitive flexibility.
The observed cognitive decline was caused by changes in the brain. When we use a certain region of the brain, blood vessels provide more oxygen and blood flow to that region by swelling slightly. Diabetes can cause blood vessels in the brain to decrease in flexibility and therefore become less responsive, causing decreased blood flow and symptoms of cognitive decline.
The flexibility of blood vessels was recorded in the study and stayed consistent for participants without diabetes, while declining in those with diabetes. Blood sugar levels that fluctuate in diabetics can damage nerves and cause inflammation, affecting the reactivity of blood vessels. They found that diabetic participants who were on medication and took control of their blood sugars saw the same effect as those who did not, raising concern for the effectiveness for current treatments. Novak and colleagues are now looking into medications that work to improve blood vessel activity in diabetics and prevent future cognitive decline.
If you or a loved one has diabetes, visit your local physician to create a health plan customized to your unique needs. It is important to control blood sugar levels, keep active, eat healthy and keep up with regularly-scheduled appointments to promote your overall health and wellbeing.