Type 2 diabetes
usually occurs as a result of genetics and lifestyle. It is characterized by abnormally high levels of blood sugar, known as glucose. Glucose is the primary source of energy for our cells that the body makes from food we ingest. The onset of type 2 diabetes is triggered when the body is no longer able to properly use insulin, the hormone that helps cells take in glucose from the blood. When glucose stays in the blood stream instead of moving into the cells, nerves and blood vessels can be damaged, thereby increasing the risk of cardiovascular disease,
stroke, blindness, kidney disease, and circulation problems.
What Is Prediabetes?
Prediabetes is a condition that precedes the onset of type 2 diabetes. It is characterized by blood glucose levels that are elevated, though not high enough to be classified as diabetes. Doctors usually refer to prediabetes as “impaired glucose tolerance" or "impaired fasting glucose". The American Diabetes Association (ADA) recommends screening for all adults 45 years old and older. Also, if you are younger than 45 and are overweight or obese and have risk factors for diabetes, you should be screened. Risk factors include:
Having prediabetes means that you are at high risk for developing diabetes and may already be experiencing adverse effects of elevated blood sugar levels.
How Do You Know If You Have Prediabetes?
During a routine office visit, your doctor can order tests, such as:
Fasting plasma glucose test—For this test, you fast overnight and have your blood glucose measured in the morning before eating. Results in the range of
100-125 mg/dL (5.6-6.9 mmol/L) indicate prediabetes.
Oral glucose tolerance test
—Again, you fast overnight and have your blood glucose measured after the fast. Then, you consume a sugary drink and have your blood glucose measured two hours later. Results in the range of
140-199 mg/dL (7.8-11 mmol/L) indicate prediabetes.
- Hemoglobin A1c (HbA1c)
— This is an indicator of your average blood sugar levels over the previous three months. Results in the range of
What Can You Do If You Have Prediabetes?
If you are diagnosed with prediabetes, it is important to take action to manage your condition. Your doctor may recommend that you lose weight by changing your diet and being physically active. Reducing your body weight, even by 5%-10%, and exercising at least 30 minutes a day can help improve your health. Participating in a behavioral modification program may further help you achieve your weight loss goals.
Because many of the lifestyle-related risk factors associated with diabetes are also risk factors for other health issues, making lifestyle changes to reduce your risk of diabetes may have a positive effect on your overall health.
Some people can take medicine to manage their blood glucose levels, though lifestyle modification is favored over pharmaceuticals as the first approach to manage prediabetes. Medicines that may be used include metformin (Glucophage), pioglitazone (Actos), and acarbose (Prandase, Precose).
How Can You Prevent Prediabetes?
The same strategies that are used to lower your risk of type 2 diabetes can be applied to prediabetes, as well. The American Diabetes Association (ADA) recommends these strategies:
- Lose weight
- Exercise for at least 150 minutes per week
- Reduce your intake of calories and fat—Also, try to eat more fiber and whole grains.
If you do have prediabetes, you can take steps to slow or avoid the progression to type 2 diabetes. It will take a lot of effort on your part, but the potential benefits—being healthy and living longer—are worth it!
Am I at risk for type 2 diabetes? Taking steps to lower the risk of getting diabetes.
National Diabetes Information Clearinghouse website. Available at:
http://diabetes.niddk.nih.gov/dm/pubs/riskfortype2/risk.pdf. Accessed July 12, 2012.
American Diabetes Association and National Institute of Diabetes, Digestive and Kidney Diseases. The prevention or delay of type 2 diabetes.
Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or Metformin.
Diabetes mellitus type 2 prevention. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/. Updated June 12, 2012. Accessed May 18, 2011.
Prediabetes. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php. Updated July 2, 2012. Accessed July 12, 2012.
Kanaya AM, Narayan KM. Prevention of type 2 diabetes: Data from recent trials.
Prediabetes FAQ. American Diabetes Association website. Available at: http://www.diabetes.org/diabetes-basics/prevention/pre-diabetes/pre-diabetes-faqs.html. Accessed July 12, 2012.
Narayan K, Imperatore G. Targeting people with prediabetes.
British Medical Journal.
Diabetes Care. 2007;30:753.
Sartor G, Schersten B, Carlström S, et al. Ten-year follow-up of subjects with impaired glucose tolerance: prevention of diabetes by tolbutamide and diet regulation.
Diabetes. 1980; 29:41.
Staphanie B, Valdez R. Estimated number of adults with prediabetes in the US in 2000: Opportunities for prevention.
Tuomilehto J, Lindstorm J. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance.
N Engl J Med
Webster’s New World Medical Dictionary. Foster City, CA: IDG Books Worldwide, Inc; 2000.
10/21/2008 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: Greaves CJ, Middlebrooke A, O'Loughlin L, et al. Motivational interviewing for modifying diabetes risk: a randomised controlled trial.
Br J Gen Pract.
10/12/2009 DynaMed Systematic Literature Surveillance
http://www.dynamicmedical.com/what.php: Crandall JP, Polsky S, Howard AA, et al. Alcohol consumption and diabetes risk in the Diabetes Prevention Program.
Am J Clin Nutr.
2/15/2010 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: American Diabetes Association. Standards of medical care in diabetes—2010. Diabetes Care. 2010;33(suppl 1:S11-61).
2/15/2010 DynaMed's Systematic Literature Surveillance
http://www.ebscohost.com/dynamed/what.php: American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2010;33(suppl 1:S62-69).
Last reviewed July 2012 by Brian Randall, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © EBSCO Publishing. All rights reserved.