Diabetes rates in the United States may be showing signs of leveling off, health officials say.

The numbers of people that live with diabetes and the rate of new cases detected annually, after rising dramatically between 1990 and 2008, then showed little change between 2008 and 2012, a report says.

"We are now for the first time showing that (those rates are) slowing down," says Ann Albright, co-author of the report in the Journal of the American Medical Association.

"We're encouraged by that but it also means that we need to continue to watch this and make sure it's not just a blip, to make sure we can sustain this and ultimately reverse this trend," says Albright, head of the Division of Diabetes Translation at the Centers for Disease Control and Prevention in Atlanta.

The news is not all good, the report points out; while the average rates for all U.S. adults may be leveling off, they continue to rise among African-Americans and Hispanics.

The report on trends seen in rates of Type 1 and Type 2 diabetes was based on medical data from 1980 to 2012 on 665,000 adults between the age of 20 and 79.

After remaining stable through most of the 1980s, there were significant increases, and the diabetes rate reached 7.9 percent by 2008.

Since then, however, the rate has apparently stabilized, with neither the number of people with the disease nor the rate of new cases changing much since that year.

That suggests "a potential slowing in the diabetes epidemic," study co-author Linda Geiss, also of the CDC, said.

Nevertheless, compared to 1990 the rate has doubled and diabetes remains a considerable concern in public health, the report authors emphasize.

The leveling off of the rate of diabetes incidence may be linked to a slowing rate of obesity, they suggested, citing recent studies showing the obesity rate in the U.S. has also leveled off since 2004.

"The interventions that are effective in treating obesity and preventing type 2 diabetes, we know what those are," Albright says. "We need to be implementing them on a wider scale if we're going to turn this tide."

Around 29 million people in America, some 9 percent of the country's population, suffer from diabetes, the CDC says, with around 30 percent of them undiagnosed.

The disease is the seventh leading cause of death in the United States, although the CDC notes it is often underreported on death certificates.