The brain's resistance to the action of insulin can lead to cognitive decline experienced in Alzheimer's sufferers, according to recent research.
Correlating the brain and insulin response has coined the term "type 3 diabetes" for Alzheimer's disease. But will the name stick?
Rhode Island Hospital researcher, Suzanne de la Monte, M.D., found a link between diabetes and mediators of neuronal injury that help Alzheimer’s disease spread.
The ability of the brain to respond to insulin is important for normal function but is resisted at some point, according to the research. This is why it is associated with the symptoms found in Alzheimer’s sufferers.
The University of Pennsylvania’s study, the first to show that insulin resistance occurs, indicated that Alzheimer’s could develop without a significant amount of hyperglycemia (increased blood sugar).
The researchers tested the brains of deceased non-diabetic patients with Alzheimer's disease to demonstrate that even with normal blood sugar levels, those brains showed that they were resistant to insulin activation.
Type 1 and type 2 diabetes are characterized by hyperglycemia. The term "Alzheimer’s type 3 diabetes" was coined to differentiate those who did not activate various proteins in the insulin-signaling pathways, but may have normal blood sugars.
According to Diabetes.co.uk, those with insulin resistance increase their risk of Alzheimer’s by about 50 to 65 percent.
The University of Pennsylvania research showed that type 2 diabetics produce protein deposits, known as amyloid beta, in their pancreases. These protein deposits are analogous to those found in the brain tissue of Alzheimer’s patients.
Alzheimer’s disease occurs when nerve cells in the brain die, inhibiting brain signaling. There is no definitive test for Alzheimer's disease.
The symptoms of Alzheimer’s disease include problems with memory, judgment and thinking, according to WebMD.com.
Nerve cell death occurs gradually over a period of years. The course of Alzheimer's disease could last from two to three years or as long as 20 years, according to WebMD.com. In most cases, the parts of the brain that control memory and thinking are affected first, but as time progresses, cells die in other parts of the brain.
Alzheimer’s was once thought to be rare, according to WebMD.com, but now accounts for about half of all cases of dementia and is being referred to as type 3 diabetes.
Researchers continue their quest to understanding the link between diabetes, insulin resistance and Alzheimer’s disease.
Sources:
Type 3 Diabetes
Diabetes.co.uk. Retrieved October 7, 2012.
http://www.diabetes.co.uk/type3-diabetes.html
Rhode Island Hospital Study Finds Link Between Brain Insulin Resistance and Neuronal Stress in Worsening Alzheimer’s Disease
Rhode Island Hospital. Retrieved October 8, 2012.
http://www.rhodeislandhospital.org/wtn/Page.asp?PageID=WTN000249
Brain Insulin Resistance Contributes to Cognitive Decline in Alzheimer's Disease
Penn Medicine. Retrieved October 8, 2012.
http://www.uphs.upenn.edu/news/News_Releases/2012/03/insulin/
Alzheimer's Disease
WebMD.com. Retrieved October 8, 2012.
http://www.webmd.com/alzheimers/mental-health-alzheimers-disease
Reviewed October 9, 2012
by Michele Blacksberg RN
Edited by Jody Smith