July 8 (HealthDay News) -- Rising levels of a blood protein called fetuin-A may indicate an elevated risk of developing type 2 diabetes, new research suggests.

Reporting in the current issue of the Journal of the American Medical Association, researchers from the University of California, San Diego, found that older people with the highest levels of fetuin-A were more likely to develop diabetes than those with lower levels.

"If fetuin-A can really differentiate diabetes risk, it gives us an opportunity for public health interventions," said the study's lead author, Dr. Joachim Ix, an assistant professor of medicine at the University of California, San Diego, and the San Diego Veterans Affairs Healthcare System.

Ix said that interventions to fight diabetes, such as healthy diet and exercise, can be difficult to accomplish on a wide scale. However, efforts could be made easier "if we could use something like fetuin to identify people with the highest risk," he said.

According to the American Diabetes Association (ADA), almost 21 million Americans now have diabetes. Most of them have the type 2 form of the disease, which is often linked to obesity. People with type 2 diabetes either don't produce enough insulin, or their bodies become desensitized to insulin and can't effectively use it. Untreated, diabetes can lead to a number of complications, including heart disease, stroke, kidney failure, blindness and more, according to the ADA.

The exact cause of type 2 diabetes still remains elusive. For example, being overweight is a significant risk factor for developing the disease, but not everyone who's overweight or obese will become diabetic. Fetuin-A is a protein secreted by liver cells that may play a role in insulin resistance -- the precursor to type 2 diabetes.

The current study included 406 people between 70 and 79 years old, all of who had their fetuin-A levels measured at the beginning of the study. At the time, none of them had diabetes.

Six years later, 135 of the study participants had developed diabetes.

Those with the highest fetuin-A levels had twice the risk of diabetes than those with the lowest levels -- 13.3 per 1,000 person-years compared to 6.5 cases per 1,000 person-years, the researchers found.

The team adjusted the data to account for other known diabetes risk factors, such as age, physical activity levels, body mass, and more. The association between diabetes and fetuin-A remained, except for when the researchers controlled for abdominal fat.

"When we adjusted for visceral fat, the link between fetuin and diabetes was still there, but was weaker," said Ix.

One expert said the findings are likely only a beginning.

"This is a very preliminary result which suggests that there might be a relationship between fetuin-A and diabetes, and this study suggests a potential target for drug development, but it's something that will take years to tease out," said Dr. John Buse, president of medicine and science at the American Diabetes Association, and director of the diabetes care center at the University of North Carolina School of Medicine, Chapel Hill.

Ix agreed that the findings need to be confirmed by other researchers. But he also believes that this work is a jumping off point for other research.

"This study suggests that there are factors coming from the liver that might control glucose, and there's a chance that this might ultimately lead to new treatments and screening strategies," said Ix.

SOURCES: Joachim Ix, M.D., assistant professor, medicine, division of nephrology, department of family and preventive medicine, University of California, San Diego, and assistant professor, medicine, nephrology section, San Diego Veterans Affairs Healthcare System; John Buse, M.D., president, medicine and science, American Diabetes Association, and director, diabetes care center, University of North Carolina School of Medicine, Chapel Hill; July 9, 2008, Journal of the American Medical Association