July 8, 2008 -- Older people with high levels of a liver-related protein are more likely to develop type 2 diabetes, according to a new study.
Scientists have previously linked high levels of the protein, called fetuin-A, with insulin resistance, but the protein's role in the development of diabetes has been unclear. Fetuin-A is produced by the liver and released into the bloodstream.
For the current study, Joachim H. Ix, MD, of the University of California, San Diego, and San Diego Veterans Affairs Healthcare System, and colleagues examined whether fetuin-A levels influenced an older person's risk of diabetes.
The trial involved 406 people aged 70 to 79 who were initially diabetes-free and who had their fetuin-A levels measured at the study's start. During the six years of follow-up, 135 participants developed diabetes.
The occurrence of diabetes increased along with fetuin-A levels. Older adults with the highest levels of the protein had more than twice the rate of diabetes than those with the lowest levels. The association was independent of other risk factors for diabetes, such as obesity, a sedentary lifestyle, and other signs of insulin resistance. Researchers noted a moderately weakened association after adjusting for visceral fat, or fat in the belly area.
The study is published in the July 9 issue of The Journal of the American Medical Association.
Researchers encourage future studies to evaluate whether the results would apply to middle-aged adults, the population that accounts for the largest number of new diabetes cases. "If confirmed in future studies, fetuin-A may ultimately prove useful as a target for therapeutics and its study may provide novel insights to glucose metabolism in humans," the authors conclude in the journal article.
Nearly 24 million people in the U.S. have diabetes. Type 2 diabetes is the most common form of the disease.