More than a third of adults estimated to have prediabetes
Nearly 26 million Americans have diabetes, according to new estimates from the Centers for Disease Control and Prevention (CDC). In addition, an estimated 79 million U.S. adults have prediabetes, a condition in which blood sugar levels are higher than normal, but not high enough to be diagnosed as diabetes. Prediabetes raises a person's risk of type 2 diabetes, heart disease and stroke.

Diabetes affects 8.3 percent of Americans of all ages, and 11.3 percent of adults aged 20 and older, according to the National Diabetes Fact Sheet for 2011. About 27 percent of those with diabetes—7 million Americans—do not know they have the disease. Prediabetes affects 35 percent of adults aged 20 and older.

"These distressing numbers show how important it is to prevent type 2 diabetes and to help those who have diabetes manage the disease to prevent serious complications such as kidney failure and blindness," said Ann Albright, Ph.D, R.D., director of CDC's Division of DiabetesTranslation. "We know that a structured lifestyle program that includes losing weight and increasing physical activity can prevent or delay type 2 diabetes."

CDC is working on the National Diabetes Prevention Program, as stated in the Affordable Care Act. This program, based on the NIH-led Diabetes Prevention Program research study, is aimed at helping people reduce their risk for developing type 2 diabetes.

In 2008, CDC estimated that 23.6 million Americans, or 7.8 percent of the population, had diabetes and another 57 million adults had prediabetes. The 2011 estimates have increased for several reasons:

• More people are developing diabetes.
• Many people are living longer with diabetes, which raises the total number of those with the disease. Better management of the disease is improving cardiovascular disease risk factors and reducing complications such as kidney failure and amputations.
• Hemoglobin A1c is now used as a diagnostic test, and was therefore incorporated into calculations of national prevalence for the first time. The test, also called glycated hemoglobin, measures levels of blood glucose (sugar) over a period of two to three months. Because of this change, estimates of populations with diabetes and prediabetes in the 2011 fact sheet are not directly comparable to estimates in previous fact sheets.

In a study published last year, CDC projected that as many as 1 in 3 U.S. adults could have diabetes by 2050 if current trends continue. Type 2 diabetes, in which the body gradually loses its ability to use and produce insulin, accounts for 90 percent to 95 percent of diabetes cases. Risk factors for type 2 diabetes include older age, obesity, family history, having diabetes while pregnant (gestational diabetes), a sedentary lifestyle, and race/ethnicity. Groups at higher risk for the disease are African-Americans, Hispanics, American Indians/Alaska Natives, and some Asian-Americans and Pacific Islanders.

Other data from the fact sheet:

• About 215,000 Americans younger than age 20 have diabetes. Most cases of diabetes among children and adolescents are type 1, which develops when the body can no longer make insulin, a hormone that controls the amount of blood glucose.
• An estimated 1.9 million Americans were diagnosed with diabetes in 2010.
• Racial and ethnic minorities continue to have higher rates of diabetes after adjusting for population age differences. For adults, diabetes rates were 16.1 percent for American Indians/Alaska Natives, 12.6 percent for blacks, 11.8 percent for Hispanics, 8.4 percent for Asian-Americans, and 7.1 percent for non-Hispanic whites.
• Half of Americans aged 65 and older have prediabetes, and nearly 27 percent have diabetes.

The fact sheet estimates are drawn from a variety of sources, including CDC surveys, the Indian Health Service National Patient Information Reporting System, the U.S. Renal Data System of the National Institutes of Health, the U.S. Census Bureau, and published studies. The fact sheet was prepared in collaboration with a number of agencies within the U.S. Department of Healthand Human Services, other federal agencies, and the American Association of Diabetes Educators, the American Diabetes Association, and the Juvenile Diabetes Research Foundation International.

Diabetes is the seventh leading cause of death in the United States. People with diabetes are more likely to suffer from complications such as heart attacks, strokes, high blood pressure, kidney failure, blindness and amputations of feet and legs. Diabetes costs $174 billion annually, including $116 billion in direct medical expenses.

The fact sheet is available at www.cdc.gov/diabetes. Information on diabetes prevention and control from the National Diabetes Education Program—a joint effort of CDC and NIH—is available at www.yourdiabetesinfo.org.