Harvard Health Letter

Ask the doctor: Prediabetes: signaling a need for lifestyle change

Q. My doctor says my blood sugar is high, and that I may be at risk for prediabetes. What is prediabetes and how can I avoid it?

A. Prediabetes is a condition between normal health and full-blown diabetes, a condition that puts you at greater risk for developing diabetes. If you have been fasting for 8 hours or more, and you have a blood glucose (a kind of sugar) level of 100 to 125 mg/dL, you have prediabetes. If you have a level of 126 mg/dL or greater, you have full-blown diabetes. If you have prediabetes, particularly if your fasting blood glucose levels are in the upper part of the 100-125 mg/dL range, you are a considerably greater risk for developing the most common form of diabetes, type 2 diabetes. You can reduce your risk of getting both prediabetes and diabetes with the same strategies: regular moderate exercise and keeping a healthy weight. In fact, such lifestyle changes are more powerful in preventing diabetes or prediabetes than any medicine yet discovered. And regular moderate exercise—like 30 minutes of brisk walking at least 5 times a week—protects you against diabetes even if you don't lose weight.

—Anthony L. Komaroff, M.D.
Editor in Chief
Harvard Health Letter

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