Screening Tests for Adults (50 and Up)

Diabetes is the sixth leading cause of death in the United States, and your risk for this disease increases with age. About 21 percent of Americans 60 years of age or older have diabetes. One third of the 20 million Americans who have diabetes don't even know it. Another 40 million have been tested and learned they have prediabetes. Recognizing prediabetes lets you take steps to stop or slow the development of type 2 diabetes, heart disease, and stroke. Diabetes leads to expensive complications and serious disabilities, including damage to the eyes, kidneys, nerves, and heart. Early detection of problems gives you the chance to make changes and take medicine that can help prevent type 2 diabetes from developing.

Many of the current guidelines advise a selective, rather than universal, approach to screening for diabetes mellitus. Note the wording in the recommendations of the National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK). It emphasizes who should "consider" getting tested (who should discuss it with their health care provider) and for whom testing is "strongly recommended."

• Anyone 45 years of age or older should consider getting tested for diabetes.
• If you are at least 45 years old and overweight, it is strongly recommended that you get tested by your health care provider.
• If you are younger than 45, overweight, and have one or more risk factors (listed below), you should consider testing.

In addition, the U.S. Preventive Services Task Force (USPSTF) published updated recommendations in 2008 in favor of screening adults who have a blood pressure reading of greater than 135/80 mm Hg. The USPSTF, however, does not recommend screening of asymptomatic adults with blood pressure below that threshold due to the lack of evidence to assess the balance of benefits and harms.

A fasting plasma glucose (FPG) test or a 2-hour oral glucose tolerance test (OGTT) can be used to screen for diabetes. In addition to those tests, the American Diabetes Association (ADA) says that an A1c test may be a screening option for some people. However, A1c should not be used for diabetes diagnosis in pregnant women, people who have had recent severe bleeding or blood transfusions, those with chronic kidney or liver disease, and people with blood disorders such as iron-deficiency anemia, vitamin B12 anemia, and hemoglobin variants. Also, only A1c tests that have been referenced to an accepted laboratory method (standardized) should be used for diagnostic or screening purposes. Currently, point-of-care tests, such as those that may be used at a doctor's office or a patient's bedside are too variable for use in diagnosis but can be used to monitor treatment (lifestyle and drug therapies).

The ADA suggests how often to repeat screening:

• All adults 45 years of age and older should be considered for diabetes screening by their health care provider every 3 years, particularly those with a body mass index greater than 25 kg/m2. If you have prediabetes, have your blood glucose checked again in 1 to 2 years, advises the NIDDK.
• In those who are overweight, testing should begin at an earlier age if additional risk factors are present and be repeated sooner.

Know your risk factors
The American College of Endocrinology and the American Association of Clinical Endocrinologists jointly recommend that you get tested for diabetes starting at 30 years old if you are in a high-risk group due to any of the following:

Your family:

• Your sister, brother, or parent has or had diabetes.
• You are of Latino/Hispanic, African, Asian, Native American, Native Alaskan, or Pacific Island descent.

Your health:

• You are overweight or have a sedentary lifestyle.
• You have hypertension, cholesterol levels (triglycerides or high-density lipoproteins) of concern, heart or vascular disease, or a severe psychiatric illness.
• Prior tests showed you had impaired glucose tolerance or impaired fasting glucose.

Women's health issues:

• You had gestational diabetes or gave birth to a baby larger than 9 pounds.
• You have polycystic ovary syndrome.

Links
NIDDK: Am I at Risk for Type 2 Diabetes?
NHLBI: Calculate Your Body Mass Index
College of American Pathologists: MyHealthTestReminder.com - Diabetes Tests

Sources

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American Diabetes Association. Standards of medical care in diabetes—2008 (position statement). Jan 2008. Diabetes Care 31:S12-S54 Available on the Internet through http://www.care.diabetesjournals.org. Accessed 18 Feb 2008.

National Institute of Diabetes and Digestive Kidney Diseases, National Institutes of Health. National diabetes statistics (NIH pub. 06–3892). Nov 2005. Available on the Internet at http://diabetes.niddk.nih.gov/dm/pubs/statistics/index.htm#12 through http://diabetes.niddk.nih.gov. Accessed 19 Feb 2008.

U.S. Preventive Services Task Force. Screening for type 2 diabetes mellitus in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2008 Jun 3; 148:846. [Erratum in: Ann Intern Med 2008 Jul 15; 149:147.]

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