Research has repeatedly shown that people with diabetes have an increased risk of developing Alzheimer’s disease. Additionally, some studies have demonstrated that intra-nasal insulin, sometimes used to treat diabetes, may help improve memory in those already diagnosed with Alzheimer’s disease. This background of knowledge prompted a group of researchers from the University of Arizona to conduct their own research to see if high blood sugar levels in people who have yet to develop diabetes may also increase their chances of developing Alzheimer's. The results have shown that this is likely the case.
The University of Arizona study included 124 men and women aged 47 to 68 who were did not have diabetes and still had normal brain function. The participants did have a family history of Alzheimer's. The study included brain scans that revealed metabolic activity in the brain.
Studies on people with Alzheimer's disease have shown reduced brain metabolism in some brain regions. This new study showed a similar pattern of lower metabolism in these same brain regions in diabetes-free participants with high blood sugar levels.
According to an article published May 8 on HealthDay.com, study author Christine Burns, a pre-doctoral student in psychology, has said that she hopes these new findings will be useful in ongoing work designed to develop early Alzheimer's interventions.
"A lot of valuable research is focused on treatment and slowing decline in Alzheimer's patients," she said. "I'm interested in complementing this work with interventions that can be implemented earlier on, perhaps at middle age." The findings were published in the journal Neurology.
Diabetes, insulin and Alzheimer’s
In July of 2010, USA Today ran an online story titled, “Insulin via nasal spray shows benefit in Alzheimer's patients.” The story reported on a study conducted by researchers at the VA Puget Sound Health Care System/University of Washington-Seattle. This particular study demonstrated results of a short-term trial using intranasal insulin for treatment of people with mild cognitive decline. The study shows some benefits on certain memory and functioning tests.
Later, in June of 2012, an article on the University of California, San Francisco (UCSF) website reported on a 9-year long study by their researchers in conjunction with the San Francisco VA Medical Center. The objective of the study was to determine if diabetes mellitus (DM) increased risk of cognitive decline and if, among elderly adults with DM, poor glucose control is related to worse cognitive performance.
The 9-year long Health, Aging, and Body Composition (Health ABC) Study enrolled 3,069 adults over 70 at two community clinics in Memphis, TN and Pittsburgh, PA beginning in 1997. All the patients provided periodic blood samples and took regular cognitive tests over time.
The researchers said that, while the underlying mechanism that accounts for the link between diabetes and risk of cognitive decline is not completely understood, it may be related to a human protein known as insulin degrading enzyme, which plays an important role in regulating insulin, the key hormone linked to diabetes. The researchers connected their findings to Alzheimer’s in that this same enzyme also degrades a protein in the brain known as beta-amyloid, a brain protein linked to Alzheimer’s disease.
Accumulating evidence suggests a strong connection between blood sugar levels and Alzheimer’s disease. It stands to reason that most of us should, at the minimum, eat well enough to keep our blood sugar levels as steady as possible and to follow any other advice our physicians may give us to help prevent diabetes.
Considering that diabetes itself is difficult enough to manage, perhaps the fear that high blood sugar levels may heighten one’s risk of developing Alzheimer’s could give people the extra push they need to better manage their diet and enhance their chances of avoiding both diseases.
HealthDay. (2013, May 8) High Blood Sugar May Add to Alzheimer's Risk: Study. Retrieved from http://health.usnews.com/health-news/news/articles/2013/05/08/high-blood-sugar-may-add-to-alzheimers-risk-study
Marcus, B. (2010, July 14) Insulin via nasal spray shows benefit in Alzheimer's patients. USA Today. Retrieved from http://usatoday30.usatoday.com/news/health/2010-07-15-insulin15_ST_N.htm
Published On: May 25, 2013