Why Is Alzheimer’s Disease Being Called Type 3 Diabetes?
“It’s really more of a research term, rather than a medical term,” says Guojun Bu, PhD, a professor of neuroscience and associate director of the Center for Regenerative Medicine at the Mayo Clinic in Jacksonville, Florida. It’s a way to identify the growing body of research into the relationships between insulin resistance in the brain and neurodegenerative conditions that can result in cognitive decline, Alzheimer’s disease, or other types of dementia.
“Individuals who have diabetes have an increased risk of Alzheimer’s disease and related dementias in later life,” says Dr. Snyder. “The exact mechanisms are not fully understood. However, when we look at the way that our brains are processing energy, it seems that that process changes in people with diabetes.” This gene is important because of its link to Alzheimer’s disease. “Twenty percent of the general human population carries at least one allele for the APOE4,” Dr. Bu points out. (An allele is a variant of a gene, and they come in pairs, with one inherited from each parent.) “Somewhere between 50 percent and 70 percent of people with Alzheimer’s disease carry at least one copy of the allele, making it a strong risk factor.” Genetic testing is available for the APOE4 gene and other variants through testing services such as 23andMe. But it’s worth noting that the gene is only a risk factor, and not everyone who has it will develop the disease. Bu points out that ongoing research is exploring potential treatments for preventing Alzheimer’s disease in people with insulin resistance. Knowing how a person’s genetic profile affects the progression of the disease could help healthcare providers customize treatments in the future.
“My advice to somebody, whether they have or don’t have diabetes, is that if they want to try to minimize their risk for Alzheimer’s disease, then try to do the things that guard against insulin resistance, such as staying lean and exercising,” Kahn says. Additional reporting by Moira Lawler. Learn more about the relationship between these two conditions in Diabetes Daily’s article “Alzheimer’s Disease and Diabetes: What’s the Connection?”
