Southern States Make Up Much of ‘Diabetes Belt’

March 7, 2011 -- The CDC says the highest rates of type 2 diabetes in the U.S. are in a “diabetes belt” in 15 mostly Southern states.

Researchers say the diabetes belt is similar to a “stroke belt” identified in earlier studies.

The diabetes belt includes 644 counties in portions of Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, and West Virginia.

Nearly a third of the difference in diabetes prevalence between the diabetes belt and the rest of the U.S. is associated with sedentary lifestyles and obesity.

“Identifying a diabetes belt by counties allows community leaders to identify regions most in need of efforts to prevent type 2 diabetes and to manage existing cases of the disease,” says Lawrence E. Barker, PhD, in a news release.  Barker is with the CDC’s division of diabetes translation.

“Although many risk factors for type 2 diabetes can’t be changed, others can,” Barker says. “Community design that promotes physical activity, along with improved access to healthy food, can encourage the healthy lifestyle changes that reduce the risk of developing type 2 diabetes.”

Diabetes Belt Demographics

The researchers identified four factors that distinguished the diabetes belt from the rest of the U.S.:

• The population of the diabetes belt counties contained substantially more non-Hispanic African-Americans than the rest of the country. In percentage terms, 23.8% of people in the diabetes belt were non-Hispanic African-Americans, compared to 8.6% for the rest of the country.
• 32.9% of people in the diabetes belt were classified as obese, compared to 26.1% in the rest of the country.
• 30.6% of people in the diabetes belt counties were judged to lead sedentary lifestyles, greater than the 24.8% for the rest of the nation.
• Only 24.1% of people in the diabetes belt counties have a college degree vs. 34.2% in the rest of the U.S.

“People who live in the diabetes belt will reduce their chance of developing type 2 diabetes if they are more active physically and, for those who are overweight or obese, if they lose weight,” Barker says. “Taking these steps will eventually lower the prevalence of diabetes within the diabetes belt.”

Stroke Belt vs. Diabetes Belt

A previously identified “stroke belt” has similarities to the diabetes belt. For example, the stroke belt includes Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia.

“Diabetes is similar to stroke in that it is strongly affected by behavioral, cultural and environmental factors clustered and overlaid on genetic susceptibility,” the researchers write.

Until now, though, patterns of diabetes have not been specifically identified by county, and knowing where the prevalence of diabetes is highest could help planners and others reduce the risk of type 2 diabetes, according to the study.

Though maps of the two disease belts are similar, they are not identical. For example, much of West Virginia is in the diabetes belt but not in the stroke belt. No counties in Indiana are in the diabetes belt, but the state is part of the stroke belt.

Portions of Georgia, mostly in the northern part of the state, are not in the diabetes belt.

One of the differences between people in the diabetes belt and the rest of the U.S. is that the diabetes belt has a greater percentage of non-Hispanic African Americans. This suggests “that interventions that are specifically targeted toward” people of African-American ancestry would be appropriate, the researchers say.

Other factors contributing to the higher rate of diabetes in Southern states may include social and cultural factors.

“It is strongly recommended that public health officials consider culturally appropriate interventions to decrease obesity and sedentary lifestyle for counties within the diabetes belt,” the CDC says.

The research is published in the March issue of the American Journal of Preventive Medicine.