Home
You can view the current or previous issues of Diabetes Health online, in their entirety, anytime you want.
Click Here To View
See if you qualify for our free healthcare professional magazines. Click here to start your application for Pre-Diabetes Health, Diabetes Health Pharmacist and Diabetes Health Professional.
Latest Insulin Articles
Popular Insulin Articles
Highly Recommended Insulin Articles
Email to a Friend
Send a link to this page to your friends and colleagues.
Is Alzheimer's a Form of Diabetes?
Insulin resistance specifically in the brain is being proposed as the reason for the memory loss that characterizes Alzheimer's disease. Because Alzheimer's may be caused by insulin-related dysfunction, some scientists are calling Alzheimer's by a new name: type 3 diabetes.
Insulin, according to previous research, is produced in the brain as well as in the pancreas. During early Alzheimer's, the brain's insulin levels and the quantity of its insulin receptors fall quickly, and they continue to drop progressively as the disease advances. In its most advanced stage, an Alzheimer brain has nearly eighty percent fewer insulin receptors than a normal brain. Thus, insulin resistance in the brain is associated with Alzheimer's disease.
Until now, exactly why the insulin receptors disappear has not been known. But now researchers from Northwestern University think they have it figured out.
First, here's a short lesson on how neurons (brain cells) communicate. Neurons have three parts: tree-shaped dendrites, a cell body, and a long axon. To get from one neuron to the next, information from the first neuron flows from its cell body, down its axon, then across a little space called a synapse, to the dendrites of the next neuron. When all is working well, insulin binds to insulin receptors on the dendrites at a neuron's synapse, turning on a mechanism necessary for nerve cells to survive and memories to form.
But now researchers have found that a toxic protein in the brains of Alzheimer's patients prevents insulin receptors from setting up for business at the neuronal dendrites. The toxic proteins, called ADDLs (short for "amyloid beta-derived diffusible ligands"), are small proteins that accumulate at the beginning of Alzheimer's disease. ADDLs bind to the neuron dendrites, hogging the spots and preventing insulin receptors from gathering there.
As a result, the insulin receptors pile up in the cell bodies where the insulin can't get to them. Because the bound ADDLs prevent the insulin receptors from getting near the synapses, there is a rapid loss of insulin receptors from the dendritic surfaces of the neurons. This is why nerve cells become insulin resistant in Alzheimer's.
The researchers found that neurons that had ADDLs bound to them had no insulin receptors on their dendrites. Conversely, the dendrites with lots of insulin receptors had no bound ADDLs. They think that ADDLs, because they block the insulin receptors from reaching the synapses, are a major factor in the memory deficits in Alzheimer's patients. In fact, they believe that insulin resistance in the Alzheimer brain is a response to ADDLs, which, by disrupting insulin signaling, are causing a brain-specific form of diabetes.
* * *
Sources: The FASEB Journal; BBC News; Diabetes in Control; Science Daily, September 2007
Categories: Diabetes, Diabetes, Geriatrics, Insulin, Professional Issues
You May Also Be Interested In...
-
Diabetes Health
Diabetes Health is the essential resource for people living with diabetes- both newly diagnosed and experienced as well as the professionals who care for them. We provide balanced expert news and information on living healthfully with diabetes. Each issue includes cutting-edge editorial coverage of new products, research, treatment options, and meaningful lifestyle issues.
-
Topics
- Diabetic / Diabetes Health
- Type 1 / 1.5 Diabetes
- Type 2 Diabetes
- Blood Glucose / Sugar
- High/Low Blood Sugar / Fast Acting Glucose
- Insulin- Pumps, Pens & Syringes
- Continuous Glucose Monitors, CGM, Infusion Sets
- Type 2 Medications
- Hyperglycemia
- Hypoglycemia
Comments
Researchers in Canada discovered that diabetes is caused by inflammation and is a nervous system problem. I wonder if type 3 diabetes (Alzheimer's) is also caused by inflammation. Dr. Richard Bernstein in his book, The Diabetes Solution, writes that his diabetic patients often have dementia-like symptoms. I have type 2 diabetes, which is under good control (A1c 6%), but my memory is horrible. By keeping my blood sugar in normal range, I feel that the glucose is not reaching my brain. I feel better and think clearer when my blood sugar is around 150. When my blood sugar is 80-90, I am irritable and cannot think straight. I often wonder if my brain needs more glucose because my brain is insulin-resistant too.
Add your comments about this article below. You can add comments as a registered user or anonymously. If you choose to post anonymously your comments will be sent to our moderator for approval before they appear on this page. If you choose to post as a registered user your comments will appear instantly.
When voicing your views via the comment feature, please respect the Diabetes Health community by refraining from comments that could be considered offensive to other people. Diabetes Health reserves the right to remove comments when necessary to maintain the cordial voice of the diabetes community.
For your privacy and protection, we ask that you do not include personal details such as address or telephone number in any comments posted.
Don't have your Diabetes Health Username? Register now and add your comments to all our content.
Register...
Register your Diabetes Health Username here.
Have Your Say...