Before type 2 diabetes sets in, blood sugar hovers in an elevated limbo state. Here's how to tell if you're affected—and how losing weight can halt the progression of prediabetes.

When it comes to prediabetes, Americans can't afford to be misinformed. Prediabetes is real—so real, in fact, it affects an estimated 57 million of us. It's defined by a sustained elevation in blood sugar, which starves the body's other cells of fuel and plays havoc with the circulatory system.

Health experts once referred to prediabetes with clinical-sounding terms such as "impaired glucose tolerance." Now they've redubbed it so the consequences are clear: If allowed to progress, prediabetes can morph into type 2 diabetes, a chronic malfunction in glucose (sugar) metabolism that can lead to problems from skin infections and bone thinning to heart disease and nerve damage.

The good news is, prediabetes is often reversible. It rarely produces symptoms though, and according to a report in the American Journal of Preventive Medicine, fewer than 10 percent of sufferers know they have it.

How Prediabetes Affects Your Body

Some experts call prediabetes a "Western problem," which is a delicate way of saying we've brought this scourge upon ourselves. They seem to be right. Today's overscheduled, multitasking approach to living is rigged for weight gain and lack of physical movement—the two biggest risk factors for prediabetes.

"Americans are working harder than ever, and it's difficult to make time to exercise and shop for healthy meals," acknowledges Susan Herzlinger Botein, an attending physician at the Joslin Diabetes Center in Boston.

Fat tissue, compared with lean muscle, doesn't respond as well to insulin—and this hormone is critical to moving glucose out of the bloodstream and into the cells that need it. Plus, the insulin demands of an overweight body can simply exceed what the pancreas is able to produce. And because exercise enhances the body's glucose metabolism, time-strapped women who skip workouts put themselves at an added disadvantage.

Research shows that a body-mass index of just 25—this would apply to a 5-foot-5 woman weighing 150 pounds -- can ratchet up prediabetes risk.

Though the trend is difficult to track, experts say prediabetes has grown increasingly common. "Things have shifted dramatically in the last 20–30 years," reports Joel Zonszein, M.D., director of the Clinical Diabetes Center at Montefiore Medical Center in New York City. "Judging by test results from my patients, more and more people are living in a prediabetic state."

Yet millions of sufferers remain in the dark because this red flag flies in a gray area. Blood sugar hovers above normal, but isn't quite high enough to qualify as diabetes proper. "Even when doctors test for elevated blood glucose—and many don't—they sometimes fail to explain the risks and simply tell patients to come back in a year for retesting," Dr. Zonszein says. He adds that some doctors don't even mention high blood sugar specifically -- they just tell patients to lose weight and exercise without explaining how urgent those recommendations really are.

A large study conducted by the National Institutes of Health found that people with prediabetes who did nothing about it went on to develop full-blown diabetes at twice the rate of those who made lifestyle changes to correct course.

Take Control of Prediabetes

In the coming months, more Americans finally might get the diagnosis they need. The American Diabetes Association (ADA) recently added a blood test called the A1C to its list of approved diagnostic tools. This test offers a snapshot of long-term glucose control, commonly expressed as a percentage.

A healthy A1C reading is below 5.7 percent; prediabetes is 5.7 to 6.4 percent. Readings above 6.4 percent indicate type 2 diabetes. Unlike older blood tests, the A1C doesn't require fasting or guzzling a big glucose drink. This "anytime" flexibility holds the potential to make testing during routine exams much easier. And it's a good thing.

The ADA advises getting tested for prediabetes if you're 45 or older and overweight; or if you are under 45, overweight, and have any other risk factors

A diagnosis can be a lifesaving wake-up call. One major study found that just 30 minutes a day of moderate physical activity, coupled with a 5–10 percent reduction in body weight, slashed participants' risk of developing type 2 diabetes by 58 percent. (Medication sometimes is needed in advanced cases.)

Health experts hope that by proving the power of DIY measures, they can inspire people to make positive changes. "I have seen amazing results from patients who put their minds toward improving their health," attests Caroline Abruzese, M.D., president of Personalized Healthcare, an integrative health center in Atlanta. "I believe we can turn prediabetes from an epidemic into a historical footnote."

Diabetes Risk Factors

Most people with prediabetes experience no symptoms, but the following signs could mean you're at risk.

If any of these apply to you (especially if you are 45 or older), ask your doctor about glucose testing.

  • A body mass index of 25 or higher (go to for a BMI calculator)
  • Exercising for fewer than 20 minutes three times per week
  •  An immediate family member with diabetes
  • High blood pressure
  • Low HDL ("good") cholesterol or high triglycerides
  • Polycystic ovary syndrome
  • Gestational diabetes, or giving birth to a baby weighing more than 9 pounds
  • Being of African American, American Indian, Hispanic, Asian-American, or Pacific Islander descent

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