By AMERICAN HEART ASSOCIATION NEWS

0908-Feature-diabetes prevalence_Blog

About half of Asian-Americans and Hispanic-Americans with diabetes don’t know they have it, according to new research. The study, published Tuesday in the Journal of the American Medical Association, also found that half of all U.S. adults have diabetes or prediabetes.

Of the nearly 21 percent of Asian-Americans with diabetes, 51 percent were unaware of it. More than 22 percent of Hispanic-Americans have diabetes, with 49 percent undiagnosed. About 11 percent of whites and 22 percent of African-Americans have diabetes, yet only about a third are undiagnosed.

“It really is stunning that half of the Asians and Hispanics with diabetes were unaware,” said JoAnn Manson, M.D., chief of the Division of Preventive Medicine at Brigham and Women’s Hospital and professor of medicine at Harvard Medical School in Boston. “I don’t think it’s well recognized and appreciated by clinicians and the public that Asians are at higher risk of Type 2 diabetes.”

Researchers from the National Institutes of Health and the Centers for Disease Control and Prevention used data from the National Health and Nutrition Examination Surveys between 1988 and 2012 that included 26,415 adults. They found the percentage of Americans with diabetes went up during that time, from nearly 10 percent to more than 12 percent on average. The prevalence of elevated blood sugar levels, or prediabetes, was 38 percent.

The increasing prevalence of diabetes may, however, be leveling off, based on data from 2007 to 2012. And the percentage of people with undiagnosed diabetes has decreased over the decades. That suggests screening and prevention may be improving in some populations but not others, Manson said.

More Asian-Americans were surveyed in 2011-2012, allowing researchers to analyze diabetes data for the first time in this population.

Type 2 diabetes may be missed in Asian-Americans because they can develop the disease at a lower body mass index than the general population, researchers said. BMI is a measure of weight in relation to height, with obesity — a known risk factor for diabetes — being defined as a BMI of at least 30.

But Asian-Americans with a normal BMI can still develop diabetes, researchers said. This may be because Asians have smaller frames or greater percentage body fat for a given BMI, Manson suggested.

The American Diabetes Association recommends diabetes screening for Asian-Americans with a BMI of 23 or higher. The American Heart Association recommends medical professionals use waist circumference in addition to BMI to diagnose obesity in Asian-Americans.

More than 21 million U.S. adults have been diagnosed with diabetes and another 8 million are undiagnosed, according to the CDC. Nearly 81 million have prediabetes.

Diabetes affects the production of or response to insulin, a hormone that allows cells to take up glucose from the bloodstream to fuel the body’s cells. When insulin is inefficient or the body doesn’t make enough, sugar builds up in the blood, which can damage the heart, blood vessels, kidneys, eyes and nerves.

Although genetics play a role in the development of Type 2 diabetes, the disease is largely preventable, Manson said. People can maintain a healthy weight, eat a healthy diet and stay physically active, she said.

“When it comes to Type 2 diabetes, there are many things we can do to control our own destiny,” Manson said.