Constant High Blood Sugar Disables Insulin 'Off' Switch

Constant High Blood Sugar Disables Insulin 'Off' Switch
Researchers say mouse study reversing that pattern offers hope of new diabetes treatments

THURSDAY, March 6 (HealthDay News) -- Chronically high blood glucose levels disable the molecular switch that normally turns off sugar production in the liver in response to increasing insulin levels, a California study finds.

This finding suggests that inhibiting the enzymatic pathway that disables the "sugar-off" switch (CRTC2) may help lower glucose levels in people with diabetes and reduce long-term complications associated with the disease, the researchers said.

The study, by researchers at the Salk Institute for Biological Studies, in La Jolla, Calif., is published in the March 7 issue of Science.

In healthy people, the CRTC2 switch turns on glucose production in the liver when blood glucose levels decline during the night. After a meal, insulin shuts down CRTC2, thus ensuring that blood sugar levels don't rise too high.

But in many people with type 2 diabetes, CRTC2 no longer responds to increasing insulin levels. As a result, the liver keeps on pumping out glucose, even if blood glucose levels are already elevated.

In research with mice, the Salk team focused on the hexosamine biosynthetic pathway. Activation of this pathway promotes the addition of sugar molecules to proteins, a process called O-glycosylation.

"It had been known that increases in the concentration of circulating glucose activate the hexosamine biosynthetic pathway. But we had no idea that the resulting O-glycosylation would lock CRTC2 in the 'on' position," study first author Renaud Dentin said in a prepared statement.

Dentin's team decreased the activity of the hexosamine biosynthetic pathway in insulin-resistant diabetic mice and in mice fed a high-fat diet (both groups had high blood sugar levels) and found a marked improvement in glucose tolerance and insulin sensitivity.

More information

The American Diabetes Association has more about hyperglycemia.



-- Robert Preidt



SOURCE: Salk Institute for Biological Studies, news release, March 6, 2008

Last Updated: March 06, 2008

Copyright © 2008 ScoutNews, LLC. All rights reserved.

http://www.healthday.com/Article.asp?AID=613284


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  • 3/7/2008 4:40 AM keith wrote:
    This article is a great example of just how screwed up our world is.

    They admit that high blood sugar and high insulin are problems? Right?

    Why bother going into protein, enzymes, or whatever?

    Why not just tell people to stop eating high glycemic foods that cause high blood sugar and high insulin levels?

    Why are we making a mountain out of a mole hill?

    Oh that's right - how could our poor "health experts" make any $ if people did the safe, natural way of improving their health?

    And people are complaining about soaring health care costs?

    This is a great example of why health care costs are soaring.  Here is another example of where some "health experts" want to go spend billions of dollars to research something - that does not need to researched.
    Reply to this

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