A1C Test
This simple blood test measures your average blood sugar for the past two to three months. The advantages of being diagnosed this way are that you don’t have to fast or drink large amounts of anything. Note: Your doctor may report your A1C results as eAG, or “estimated average glucose,” which directly relates to your A1C.
| A1C | eAG |
Normal: | < 5.7 percent | <117 mg/dl |
Prediabetes: | 5.7-6.4 percent | 117-138 mg/dl |
Diabetes: | ≥ 6.5 percent | ≥139 mg/dl |
Fasting Plasma Glucose (FPG) Test
This test checks your fasting blood sugar levels. Since it requires fasting— taking in nothing but water for at least eight hours before the test — it’s usually done first thing in the morning.
Normal: | <100 mg/dl |
Prediabetes: | 100–125 mg/dl |
Diabetes: | ≥126 mg/dl |
Oral Glucose Tolerance Test (OGTT)
This two- to three-hour test measures your body’s response to sugar. Your doctor will check your blood sugar levels before you drink a special sweet drink and again two hours later.
Normal: | <140 mg/dl |
Prediabetes: | 140-199 mg/dl |
Diabetes: | ≥200 mg/dl |
6. Prediabetes is reversible
In the early stages of prediabetes (and diabetes, for that matter), paying attention to diet and exercise can improve blood sugar numbers, essentially “reversing” the disease and reducing the odds of developing diabetes.
The American Diabetes Association (ADA) recommends 150 minutes of moderate-intensity aerobic activity, as well as two to three strength training sessions, per week. Not only will that sort of commitment to exercise help keep your weight in check, it will also improve blood glucose levels.
And while there is no “prediabetes diet” (or, for that matter, a “diabetes diet”), the ADA recommends a number of eating plans, including Mediterranean, low-carb, vegetarian, and others that emphasize nonstarchy vegetables; whole, minimally processed foods; and little added sugar.
A few other things that may help you mitigate your risks:
- Maintain a healthy weight. If you’re overweight, even a little weight loss can help. A landmark study at the National Institutes of Health (NIH) found that lifestyle changes leading to a weight loss of 7 percent in overweight participants with prediabetes reduced their risk of diabetes by 58 percent. Participants over age 60 reduced their chances of developing diabetes by 71 percent, compared with those who didn’t lose weight.
- Talk to your doctor about whether it makes sense for you to take the drug metformin. Considered the first-line treatment to help control blood sugar for people with type 2 diabetes, the drug is also recommended by the ADA for people with prediabetes and certain other risk factors. The NIH study found that overweight participants with prediabetes who took metformin lowered their chances of developing diabetes by 31 percent, compared with those who didn’t take the drug or undergo lifestyle changes. The Food and Drug Administration hasn’t approved metformin — or any other medication —for prediabetes, so it is prescribed “off-label.”
If you have underlying risk factors that put you at greater risk for diabetes — say, for instance, you’re over age 45 or diabetes runs in your family — you’ll need to continue to pay attention to blood sugar levels and lifestyle choices. Otherwise, your prediabetes will return.
Find support for prediabetes
A support group can help you make the necessary lifestyle changes to avoid progressing to diabetes. Not sure how to find one?
The ADA organizes workshops geared to a variety of different groups. To find one near you, contact the ADA (800-DIABETES).
The Centers for Disease Control and Prevention (CDC) National Diabetes Prevention Program can also help you learn about healthy lifestyle changes — related to eating habits, exercise and more — shown to reverse prediabetes. The program is offered at YMCAs, community centers, churches and hospitals across the country. To find one near you, enter your zip code into the CDC’s program finder tool.
Similarly, Medicare offers a Diabetes Prevention Program, which is covered for many Medicare enrollees.
Editor's note: This article was originally published on November 2, 2018. It was updated on Sept. 7, 2023.
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