A diabetes tsunami is headed our way, say experts. One in three adults—and nearly one in two men—already have prediabetes. The chief culprits: two-thirds of adults (and one-third of children) are overweight or obese, and we’re a nation of couch (and computer, car, TV, and phone) potatoes. But that’s not all that matters.
“We already have a diabetes epidemic on our hands,” says Edward Gregg, chief of the Epidemiology and Statistics Branch of the Division of Diabetes Translation at the Centers for Disease Control and Prevention.
He’s talking about the 29 million American adults who have diabetes. Most have type 2, the kind that’s closely tied to obesity (unlike type 1 diabetes, which is an autoimmune disease). Type 2 used to be called adult-onset diabetes, but now it’s showing up in teens.
“There’s a fairly large proportion— roughly 28 percent—of adults with diabetes who don’t know it,” says Gregg. “And then you have a third of the adult population that’s at very high risk for diabetes. And the vast majority of people with prediabetes don’t know that they have it. That’s why we think of diabetes as an iceberg.”
Doctors use blood sugar levels to diagnose prediabetes and diabetes. But the trouble starts long before blood sugar soars out of control.
“For type 2 diabetes to develop, there are usually two problems,” says Anastassios Pittas, co-director of the Diabetes Center at Tufts Medical Center in Boston. “The first is that the body is resistant to insulin.”
Insulin acts like a key that allows sugar to enter cells, where it can be burned for fuel or stored for later. But in some people, especially those with an oversized waist, the key struggles to open the lock.
To compensate for insulin resistance— which is also called impaired insulin sensitivity—the beta cells of the pancreas pump out more and more of the hormone. The extra insulin can keep a lid on blood sugar for years, but eventually the beta cells wear out.
“At some point, the pancreas cannot make enough insulin to overcome the resistance,” says Pittas. That’s when blood sugar surges into the “diabetes” range.
Millions of Americans are headed to¬ward that breakpoint. Two reasons stand out.
“The population has steadily become more obese for the last few decades,” says Gregg, thanks in part to larger portion sizes, sugary beverages, and less exercise.
“And baby boomers are moving into the high-incidence years,” he adds. “Aside from obesity, age is the most important risk factor. Beta-cell failure occurs more rapidly with age. About 25 percent of people age 65 and older have diabetes.”
And that spells trouble.
“In many ways the population is getting healthier over time,” says Gregg. “But diabetes is an exception.”