What relationship does diabetes have with Alzheimer’s?

Almost 21 million Americans have diabetes, a disease that makes the body less able to convert sugar to energy.

Researchers reported in last October’s issue of the Journal of Alzheimer’s Disease a strong correlation between Alzheimer’s disease and high blood sugar levels. The study revealed that individuals with high blood sugar levels, such as those linked with Type 2 diabetes, had a marked increase in a protein toxic to cells in the brain, and additional evidence revealed that diabetics have a lower level of cognitive function and are at higher risk of dementia than individuals without diabetes.

A study by the Biophysical Society noted the link between Alzheimer’s disease and diabetes. The link relates to the formation of two types of peptide deposits that clump together. Peptides are chains of amino acids and longer chains form proteins.

One type of peptide is called amyloid protein, found in plaques in the neurons of the brain of someone with Alzheimer’s disease. The other type of peptide is called amylin and this peptide is found in the pancreas and the brain. Researchers in this study later found both the amyloid protein and amylin in the pancreas of a person with diabetes.

In other outcomes regarding the connection between Alzheimer’s disease and diabetes, researchers at the University of Wisconsin School of Medicine and Public Health study found that people in the early stages of diabetes showed signs of brain dysfunction. The findings showed higher levels of insulin resistance in the brains of study participants and a reduced uptake of glucose.

The brain of someone with Alzheimer’s disease shows low levels of insulin, which is significant for memory function. According to Dr. Barb Bendlin, one theory is that “brain cells become insulin resistant, which is a feature of diabetes. The brain can’t take up the sugar it needs because it is not responding to insulin, or insulin levels in the brain may be low. The hypothesis is that diabetes is a risk factor for Alzheimer’s disease, but not everyone with diabetes is going to get Alzheimer’s.”

According to the American Diabetes Association, 27 percent of people aged 65 and older in the United States have diabetes and about half have pre-diabetes.

Questions about Alzheimer’s disease or a related dementia disorder? Contact Dana Territo, the Memory Whisperer, Director of Services at Alzheimer’s Services of the Capital Area, (225) 334-7494, advice@alzbr.org, or visit the organization at 3772 North Blvd., Baton Rouge.