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Glucose Intolerance

Harvard Health Publications
2007 Copyright Harvard Health Publications


I have high blood pressure and am 8 pounds overweight. My doctor says that it is probable that I have glucose intolerance. Is this the same disease as diabetes? What should I do about it?


Glucose intolerance is also called "pre-diabetes." It can be diagnosed by testing blood after a sugar load ("glucose tolerance test"), but more often it is diagnosed by a blood test after an eight-hour fast. After a fast, if you have a glucose level in your blood that is above normal (above 100 milligrams per deciliter) but below the number that is needed to identify diabetes (126 mg/dl or higher), you have pre-diabetes.

A glucose (sugar) number in this range reveals that you have some degree of resistance to insulin, so you can't move glucose into cells efficiently and utilize it as an efficient body fuel. However, your glucose level is not high enough to cause you noticeable symptoms such as fatigue, blurred vision, frequent urination, or exaggerated thirst or hunger. It is not necessary for you to take glucose control medicines if you have pre-diabetes.

If you have pre-diabetes, you have a significant risk each year of progressing to full-blown diabetes. You also have an elevated risk for heart disease and stroke, much like people with diabetes.

You can reduce your risk for progression to diabetes if you dedicate yourself to maintaining a regular exercise program and carefully watch your weight. This can lower your risk of progression to diabetes by as much as 50 percent each year. The medication metformin (Glucophage) is occasionally used to reduce the risk of progression to diabetes. This medicine is not as effective as an exercise program and weight management, but it can help.

Your blood glucose should be tested every six to 12 months if you have pre-diabetes, so that you can begin treatment quickly if diabetes develops.

Mary Pickett, M.D., is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University in Portland, OR. At OHSU, she practices general internal medicine and teaches medical residents and students.

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Harvard Health Publications Source: from the Harvard Health Publications Family Health Guide, Copyright © 2007 by President and Fellows of Harvard College. All rights reserved.

Used with permission of StayWell.

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