Op-Ed: Prediabetes is an alarming diagnosis. But is it a disease?

Millions of Americans in recent years have received the disturbing news from their doctors that they have a potentially dangerous condition called “prediabetes.” But how alarmed they should be isn’t clear.

While everyone agrees that actual diabetes is a serious health issue, prediabetes is still a controversial diagnosis.

Let’s start with the name itself. Prediabetes is a term the American Diabetes Assn. began using in 2001 to replace the more obscure terms “impaired glucose tolerance” and “impaired fasting glucose.” If the new name sounds more alarming, that was intentional, in the hope that patients with slightly elevated blood sugar, a risk factor for diabetes, would take all possible steps to prevent the disease.

When the new phrasing was first launched, the Centers for Disease Control and Prevention estimated that 12 million Americans fit the category.

The prediabetes diagnosis has been greeted with intense interest by drug companies, which have long provided financial support to the ADA.


Over the next decade, however, the American Diabetes Assn. lowered the range of blood-sugar readings defined as prediabetic, with the CDC following in lockstep. Today, under the expanded criteria, an estimated 84 million patients are now considered prediabetic, or one in every three adults.

Prediabetes, now the second most common “chronic disease” in the United States, has no symptoms and causes no complications. And for most of those diagnosed, prediabetes is a misnomer, since they will never get diabetes whether or not they take steps to prevent it.

All experts agree that elevated blood sugar sometimes leads to diabetes, whose complications can include kidney damage, heart attacks and blindness. Experts also agree that everyone should eat healthful foods and exercise regularly.

Yet the World Health Organization and other medical bodies have rejected the prediabetes label.

The most extensive review of research findings – conducted last year by the respected Cochrane Library in London – found that up to 59% of prediabetic patients return to normal blood sugar without treatment. It also found that most prediabetics who progress to diabetes come from the higher end of the ADA blood-sugar risk spectrum – comprising the same relatively small segment of people considered at risk in 2001.

Nevertheless, the term prediabetes has created a multi-billion dollar bonanza for doctors, weight-loss programs, labs, test-kit makers and alternative remedy hucksters that is fed – and largely funded – by often-needless anxiety on the part of patients with the diagnosis.

Doctors skeptical of the prediabetes label say that many of the “treatments” patients turn to don’t produce results. Only a fraction succeed in losing significant weight and keeping it off, for example. And to some skeptics, the prevention efforts, which are largely focused on lifestyle changes, contain a cruel subtext: “If you weren’t so fat and lazy, you wouldn’t be in such trouble.”

The overwhelming dominance of self-improvement as the solution to prediabetes also ignores some important roots of high blood sugar: genetic predisposition, the stress of poverty, food deserts and economic insecurity. Such factors remain intransigently resistant to dieting and exercise. But studies show that better economic and social conditions – even without the benefit of diet and exercise counseling – can drive down diabetes rates.

WHO and others suggest that prevention could be better achieved through public policy, including taxes on sugary drinks, increasing the availability of cheap, healthy foods, and urban design that emphasizes mass transit, walking and safe outdoor exercise spaces. While such solutions can be costly and politically fraught, experts such as the Mayo Clinic’s Victor Montori note that decades of the alternative – trying to fashion individual medical solutions – have proved ineffective in preventing diabetes.

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Moreover, the prediabetes diagnosis has been greeted with intense interest by drug companies, which have long provided financial support to the ADA and many of the doctors who write its influential standards of care. Those standards offer a growing list of medicines, some of which can pose serious side effects, deemed acceptable as off-label prescriptions for some prediabetes patients.

But many experts, including WHO’s top diabetes official, oppose giving medications to prevent a disease the patient may never get. “Doctors should be careful about treating prediabetes because we are not sure whether this will result in more benefit than harm,” the Cochrane authors cautioned.

Pre-diabetes is not the only “pre-disease” to come into its own in recent years. We also now have pre-hypertension and osteopenia (pre-osteoporosis). Such classifications have caused Ivan Oransky, a physician and journalist who co-founded, to suggest a skeptical approach: If a pre-disease requires costly tests, services and potentially risky drugs of dubious benefit, he says, another pre-word might apply: “preposterous.”

Charles Piller, an investigative correspondent for Science, was a staff writer for the Los Angeles Times from 1998 to 2008. His article titled Dubious Diagnosis ran in the March 8 issue of Science.