At your last medical exam you may have been tested for type 2 diabetes as part of a basic blood panel. If you were not, should you have had your blood sugar (glucose) measured? It depends on your age, weight, blood pressure and/or other risk factors for diabetes. But, in fact, there’s a surprising amount of disagreement about screening for diabetes. Recent research and position papers have lent support to both sides of the debate.
Type 2 diabetes, previously called noninsulin dependent or adult-onset diabetes, accounts for 90 to 95 percent of cases of diabetes. Diabetes is a breakdown in the body’s ability to utilize blood sugar efficiently. Before screening became widely used, the disease was diagnosed when people developed symptoms, such as unusual thirst or frequent urination.
It’s estimated that 26 million Americans have diabetes, of whom 7 million have not been diagnosed. And those who have been diagnosed typically have had the disease many years before it was diagnosed.
Another 80 million have prediabetes. That means their blood sugar is elevated (100 to 125 mg/dL after fasting) but not high enough to be categorized as diabetes. Many of them will eventually develop full-blown diabetes.
The incidence of diabetes and prediabetes has been rising rapidly, largely because of the obesity epidemic.
Early detection of diabetes can identify cases before symptoms and complications develop. That way, people can take steps (such as losing weight, improving their diet or taking medication) to minimize the damage to organs and blood vessels caused by years of high blood sugar levels—and, it’s hoped, avoid later complications of diabetes, such as heart disease, stroke and diseases of the eyes, nerves and kidneys. Screening is usually done by simple blood tests.
Routine screening: yes
The American Diabetes Association (ADA) is the leading proponent of screening. It recommends that health care providers “consider” screening asymptomatic people starting at age 45. Overweight or obese adults should be tested earlier if they have any of the following additional risk factors: a parent or sibling with diabetes; physical inactivity; belonging to a high risk racial/ethnic group (such as blacks, Hispanics, Asians and Native Americans); high blood pressure, low HDL (“good”) cholesterol, or high blood triglycerides; a history of cardiovascular disease or of gestational diabetes during pregnancy. If results are normal, testing should be repeated at least every three years, the ADA advises.
Routine screening: maybe
In 2008, the U.S. Preventive Services Task Force, which evaluates evidence on medical matters, limited its recommendation for diabetes screening to people with higher blood pressure (defined here as sustained levels of 135/80 or higher). That’s because the combination of the two disorders greatly increases cardiovascular risk, and thus someone with both should reduce blood pressure even lower than the standard target numbers. For all other asymptomatic people, the Task Force concluded, there’s insufficient evidence to assess the value of routine testing. The decision to screen or not should be made on an individual basis.