Diabetes Blood Test Urged for All Overweight US Adults
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All overweight and obese adults in the United States should be routinely screened for abnormal blood glucose levels as part of a heart disease risk assessment, according to new government recommendations.

It's the first time the United States Preventive Services Task Force (USPSTF), a panel of medical experts that makes recommendations on the effectiveness of preventive health services, has advised that American adults ages 40 to 70 who are overweight or obese undergo a blood test for diabetes, even if they have no symptoms of the disease. Excess weight is a known — but modifiable — risk factor for Type 2 diabetes.

These updated recommendations represent a change in thinking by the task force, which last issued its diabetes-screening guidelines in 2008. At that time, the advisory group did not find enough evidence that all overweight and obese adults would benefit from having their blood sugar checked on a regular basis.

"Up to one-third of adults in the United States have abnormal blood sugar levels," said Dr. Michael Pignone, a professor of medicine at the University of North Carolina School of Medicine in Chapel Hill, and member of the USPSTF.

Abnormal blood sugar levels are a risk factor for diabetes, and the latest scientific evidence has shown that identifying people who are at risk for diabetes and its cardiovascular complications, and referring them to lifestyle-change programs early on, can reduce their health risks in the future, he said. [9 Healthy Habits You Can Do in 1 Minute (Or Less)]

The screening is targeted at the 40-to-70 age group of overweight and obese adults because the incidence of diabetes starts to tick up during these years, Pignone said. People whose tests show that their blood sugar levels are normal are recommended to be retested in three years, according to the guidelines.

But the recommendations also suggest that physicians can start screening people at earlier ages if they are at high risk for diabetes, such as those with a family history of diabetes, women who had gestational diabetes during pregnancy, or members of certain racial or ethnic groups at increased risk for the disease, such as African-Americans, Hispanics and Native Americans. 

The new recommendations were released today (Oct. 26) and are also published online in the journal Annals of Internal Medicine.

Lifestyle changes

The early detection of abnormal glucose levels in overweight and obese adults is beneficial because it helps identify people who need intensive lifestyle-change programs, Pignone told Live Science.

Studies have shown that lifestyle-change programs, which include behavioral counseling for losing weight, adopting healthier eating habits and promoting regular exercise, are effective in improving cardiovascular risk factors and reducing the progression from abnormal blood sugar levels to Type 2 diabetes, he said.

In the past, these structured programs may have been hard to find, but in the past five years they are more widely available throughout the country, thanks to good, low-cost lifestyle programs offered by the YMCA, Pignone said.

The systematic approach to screening people for diabetes that is outlined in the new recommendations is a good idea because a large number of people with blood-sugar abnormalities go undiagnosed, said Dr. Robert Gabbay, chief medical officer of Joslin Diabetes Center in Boston, who was not involved in writing the new guidelines.

If people at risk for diabetes are not identified early, they may need treatment for diabetes complications later on — meaning that the health care system missed an opportunity to provide care that could have prevented these complications from occurring, Gabbay said.  

Early detection can help to shorten the amount of time a person spends walking around with high blood sugar levels and not knowing it, which can lower their risk of developing complications, he said.

The American Diabetes Association has advocated for screening people ages 45 and older with multiple risk factors for diabetes for some time, but the task force has been more conservative in its approach, Gabbay told Live Science.

It took longer for the task force to agree with the accumulating evidence in support of more screening, but the USPSTF considers not only the available data but also the cost-effectiveness of doing routine blood glucose testing in a large swath of the population, so that might explain the time lag, he said.

Another factor that may have tipped the equation in favor of more screening is that one of the tests used to screen for diabetes — the hemoglobin A1C test — has made it much simpler for people to get a quick and accurate measurement of their blood glucose levels without needing to do an overnight fast, Gabbay said.

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