Diabetes affects nearly 21 million Americans, incurring huge economic burden to the US society, the Centers for Disease Control and Prevention (CDC) said Wednesday.

The number represents 7 percent of the American population, and among these people, more than 6 million do not know they have the disease, which is the sixth leading killer in the United States, the CDC said.

The number includes 2.6 million new diabetes cases since 2002. "Another 41 million people are estimated to have pre-diabetes, a condition that increases the risk of developing type 2 diabetes -- the most common form of the disease -- as well as heart disease and stroke," said a CDC statement.

Diabetes is a lack of control of blood sugar. Type-2 diabetes is mostly found among adults. The risk of diabetes increases with age. The condition affects about 21 percent of Americans aged 60 years or older.

"Diabetes is a leading cause of adult blindness, lower-limb amputation, kidney disease and nerve damage. Two-thirds of people with diabetes die from a heart attack or stroke, "said Dr. Frank Vinicor, director of CDC's diabetes program.

Diabetes incurs the United States a loss of about 132 billion US dollars each year, with 92 billion dollars in direct medical costs and 40 billion dollars in the losses in productivity, said the CDC.

"Recent studies have shown that people with pre-diabetes can successfully prevent or delay the onset of diabetes by losing 5 percent to 7 percent of their body weight," Vinicor said.

"This can be accomplished through 30 minutes or more of physical activity most days of the week and by following a low calorie, low fat eating plan, including a diet rich in whole grains and fruits and vegetables," he said.

Source: Xinhua