Type 3 Diabetes: What is it? How is it connected to Alzheimer's?

Have you ever heard of Type 3 Diabetes? I a recent study suggests a little more than a connection to Alzeheimer’s. Back in 2003, I visited my father a few months before he passed away… and it became very apparent to me that something was off with his mind, and memory. He didn’t remember very many current things, anymore, and often he would refer to me as if we were in another, past decade, and I was still a teenager. I asked mom if dad had developed Alzeheimer’s, but she denied that. Now, everything seems to click more in place.

Type 3 Diabetes: What is it? How is it connected to Alzheimer’s?

New Type 3 Diabetes Discovered
Discovery that insulin is produced in the brain and it’s decrease raises possibility of Type 3 diabetes linked to Alzheimer’s Disease and changes the way we view the disease.

Researchers at Rhode Island Hospital and Brown Medical School have discovered that insulin and its related proteins are produced in the brain, and that reduced levels of both are linked to Alzheimer’s disease.

“What we found is that insulin is not just produced in the pancreas, but also in the brain. And we discovered that insulin and its growth factors, which are necessary for the survival of brain cells, contribute to the progression of Alzheimer’s,” says senior author Suzanne M. de la Monte, a neuropathologist at Rhode Island Hospital and a professor of pathology at Brown Medical School. “This raises the possibility of a Type 3 diabetes.”

It has previously been known that insulin resistance, a characteristic of diabetes, is tied to neurodegeneration. While scientists have suspected a link between diabetes and Alzheimer’s disease, this is the first study to provide evidence of that connection.

By studying a gene abnormality in rats that blocks insulin signaling in the brain, researchers found that insulin and IGF I and II are all expressed in neurons in several regions in the brain.

Additionally, researchers determined that a drop in insulin production in the brain contributes to the degeneration of brain cells, an early symptom of Alzheimer’s. “These abnormalities do not correspond to Type 1 or Type 2 diabetes, but reflect a different and more complex disease process that originates in the CNS (central nervous system),” the paper states.

By looking at postmortem brain tissue from people diagnosed with Alzheimer’s disease, researchers discovered that growth factors are not produced at normal levels in the hippocampus - the part of the brain responsible for memory. The absence of these growth factors, in turn, causes cells in other parts of the brain to die. Reserachers found that insulin and IGF I were significantly reduced in the frontal cortex, hippocampus and hypothalamus - all areas that are affected by the progression of Alzheimer’s. Conversely, in the cerebellum, which is generally not affected by Alzheimer’s, scientists did not see the same drop in insulin and IGF I.

“Now that scientists have pinpointed insulin and its growth factors as contributors to Alzheimer’s, this opens the way for targeted treatment to the brain and changes the way we view Alzheimer’s disease,” de la Monte says.

The study was supported by grants from the National Institute of Alcoholism and Alcohol Abuse and from a COBRE award from the National Institutes of Health.

The findings are reported in the March issue of the Journal of Alzheimer’s Disease (http://www.j-alz.com), published by IOS Press.

Hi Lizmare! Makes sense. My mother had thyroid disease for years and then eventually ended up stage 3 Alzheimer’s during her last 10 years. I know I have read that these conditions come in clusters and often if you have one you have another. She never had a weight problem but boy how she loved sweets all her life. I lean it is in the genetic markers and environmental that causes this type of T-3. I have read about the interrelationships of the proteins in the brain for Alzheimer’s also. Thank you for the posting. Take care

T3 are those people who support us and have to put up with us and the big D.

Well, I know that it’s a loving way from TuD to include them in our struggle, but technically, T3 really is a new type of Diabetes, not the people who support us and love us.

There’s a difference in the popular definition of T3D and the scientific definition of T3D - I had this discussion with the endocrinologist who’s coauthoring my book. Most of us consider Type 3 Diabetes to be a situation where a T1D has developed T2D, but in the scientific community, Type 3 diabetes refers to a disorder of the brain in which activity of insulin and glucose uptake by brain cells is impaired. Aside from being a disorder of glucose metabolism, it is not (apparently) related to or a product of T1D, T2D, LADA, or anything combination thereof, at least not based on what is currently known now, which admittedly isn’t a lot. But she was telling me that they do think it plays a role in most cases of Alzheimer’s.