Despite some controversy about over-screening for diabetes – and about the very term “prediabetes” – all adults age 45 and older should receive screening for type 2 diabetes, according to a draft report from the US Preventive Services Task Force (USPSTF).
The report, open for public comment here, indicates that diagnosis of prediabetes is an opportunity for lifestyle-based treatment that could significantly reduce a person’s risk of developing full-blown diabetes.
Preventive screening includes a blood glucose test, which requires an eight-hour fast beforehand, a glucose tolerance test that checks blood sugar before and after drinking a sweetened beverage, or a blood test that measures average blood glucose for the past two to three months.
Adults with blood sugar levels that are higher than normal but not high enough to be classified as type 2 diabetes are considered high-risk for developing the disease.
The government-sponsored Task Force, made up of primary care physicians and researchers, based its findings on a large-scale analysis of randomized control trials, controlled observational studies and other systemic reviews. With this report, USPSTF updates its 2008 recommendations, which only advised screening for those with an increased risk of heart disease due to high blood pressure.
“More evidence has emerged since then on the benefits for screening the general population,” said Dr. Michael Pignone, professor of medicine at the University of North Carolina at Chapel Hill School of Medicine and member of the Task Force, in an interview with the Boston Globe.
Critics of overdiagnosing ‘prediabetes’
But labeling people with moderately high blood sugar as prediabetic has hit a nerve with some experts who argue that the prediabetes label is unhelpful and unnecessary.
“Prediabetes is an artificial category with virtually zero clinical relevance,” said John S. Yudkin, emeritus professor of medicine at University College London in the online research site Science Daily. Particularly with regard to pharmacological treatments for prediabetes, the risks of the diagnosis outweigh the benefits, he said, arguing that diabetes drugs such as metformin are of little to no benefit for people with prediabetes.
“There are significant financial, social and emotional costs involved with labeling and treating people in this way,” Yudkin said. “And a range of newer and more expensive drugs are being explored as treatments for ‘prediabetes.’ The main beneficiaries of such recommendations would be drug manufacturers, whose available market suddenly leaps to include significant swathes of the population.”
Yudkin and Mayo Clinic’s Victor Montori wrote over the summer in BMJ (formerly the British Medical Journal) about the downsides of overdiagnosis and creating a new “epidemic” of prediabetes. They note that, among other problems, it is a “leap of faith” to suggest that treatment of people in newly defined categories will improve mortality and morbidity.
Screening people for prediabetes is an area that “clearly needs additional study,” said John Buse, MD, PhD, of the University of North Carolina at Chapel Hill, and co-author of an editorial recently published in the online edition of Diabetes Care. But in MedPage Today, Buse argued that prescreening and preventive treatment are valuable now.
“We’re calling for earlier diagnosis and earlier treatment with the rationale being that it’s really easy to do and seems to be associated with long-term benefits.”
AMA endorses recommendation
The American Medical Association (AMA) quickly announced its support of the revised USPSTF recommendations, however. “More than 86 million Americans have prediabetes, yet nearly 90 percent don’t know they have it,” said Robert M. Wah, MD, president of AMA, in a statement.
Researchers in the pro-prescreening camp argue that, by adopting a strategy to reach people before they acquire type 2 diabetes, physicians can play a big role in stemming the rising rates of the disease.
“Diabetes is generally diagnosed and first treated about 10 years later than it could be,” said Dr. Lawrence Phillips, a researcher from Emory University and lead author in the Diabetes Care editorial. “There is a strong, new argument that by combining screening to find prediabetes and early diabetes, along with management aimed to keep glucose levels as close to normal as possible, we can change the natural history of the disease and improve the lives of our patients.”
No clear prediabetes symptoms
There are no clear symptoms of prediabetes, though some people with the condition may experience some of the symptoms of type 2 diabetes. These include frequent urination, excessive thirst or hunger, extreme fatigue, blurry vision, cuts or bruises that are slow to heal, and tingling, pain or numbness in the hands or feet, according to the American Diabetes Association.
The Centers for Disease Control and Prevention reports that 29.1 million Americans have diabetes, but nearly 28 percent, or 8.1 million, are undiagnosed.
Type 2 diabetes is the leading cause of kidney failure, non-traumatic lower-limb amputations and new cases of blindness, as well as a major cause of heart disease and stroke. It is the seventh leading cause of death in adults in the United States, according to USPSTF.
Click here for more information from the CDC on diabetes prevention.