Diabetes biomarker also indicates cognitive decline

Monday 25 June 2012

Results of a new study show a greater risk of cognitive decline among people who develop diabetes later in life. It also links the risk of cognitive decline to the severity of diabetes.

These results emerge from the Health, Aging, and Body Composition (Health ABC) Study, which enrolled 3,069 adults over 70 at two clinics, beginning in 1997. All the patients provided periodic blood samples and took regular cognitive tests over time.

When the study began, hundreds of these patients already had diabetes. A decade later, many more of them had developed diabetes and many also suffered cognitive decline. These two health outcomes were closely linked.

People who had diabetes at the beginning of the study showed a faster cognitive decline than people who developed it during the course of the study - and these people, in turn, tended to be worse off than people who never developed diabetes at all.

The research team was led by Dr. Kristine Yaffe, Professor of Psychiatry at the University of California in San Francisco. The team concentrated on a blood marker known as glycosylated haemoglobin, which measures the severity of diabetes and the ability to control it over time. They found that greater levels of this biomarker were associated with more severe cognitive dysfunction.

The link between diabetes and risk of cognitive decline is not completely understood. Dr. Yaffe said that it may be related to a human protein known as insulin degrading enzyme. This plays an important role in regulating insulin – and also degrades the amyloid beta protein.

http://archneur.jamanetwork.com/article.aspx?articleid=1183076