A recent study titled ”Individuals with Alzheimer’s disease exhibit a high prevalence of undiagnosed impaired glucose tolerance and type 2 diabetes mellitus,” conducted by Scott Turner MD, PhD from Georgetown University and colleagues, found that 43% of Alzheimer’s disease (AD) patients have undiagnosed impaired glucose intolerance. The findings were reported during last year’s Alzheimer’s Association International Conference in Boston, Massachusetts.
“The number of people with glucose intolerance (pre-diabetes) was much higher than expected. I was surprised by how many people didn’t know they were pre-diabetic, and these are individuals who already get the best medical care,” said Dr. Turner, Professor of Neurology and Program Director of the Memory Disorders Program at Georgetown University Medical Center in Washington, DC in a recent news release.
“We know from animal studies that caloric restriction prevents diseases of aging such as diabetes and Alzheimer’s,” Dr. Turner clarified in the news release. “On the flip side of the coin, having diabetes increases one’s risk of developing AD. So perhaps by improving glucose tolerance, we will prevent or delay both diabetes and Alzheimer’s.”
The findings were found by surprise when the team of researchers were enrolling patients for a phase II trial involving 128 patients, designed to examine the safety and tolerability of a drug called resveratrol for Alzheimer’s disease. All patients were assessed at baseline with an oral glucose tolerance test after an overnight fast and 2 hours later.
In total, 4% of patients had an impaired fasting glycemia and 2% had type 2 diabetes. After 2 hours, the results revealed that 30% of the patients had impaired fasting glycemia and 13% had type 2 diabetes. These results revealed a total prevalence of 43% of impaired fasting glycemia or type 2 diabetes.
Questions such as “How does glucose intolerance or diabetes lead to AD? Does the inflammation associated with AD trigger glucose intolerance? Or do both events create a vicious cycle of Alzheimer’s and glucose intolerance?”, are beyond the scope of Turner’s team study design. However, these results should inform neurologists to ask for glucose tolerance tests. “This result suggests that perhaps we should test all our patients with early Alzheimer’s. It’s a simple, inexpensive study that reveals critical health information,” adds Dr. Turner.