TUESDAY, July 7, 2009 (HealthDay News) -- Higher levels of a protein created by fat cells are associated with a lessened risk of type 2 diabetes.
The protein, adiponectin, appears to have anti-inflammatory and insulin-sensitizing capabilities, according to a study published in the July 8 issue of the Journal of the American Medical Association.
"Our finding was that adiponectin is associated with a low risk of type 2 diabetes, and the effect is quite pronounced," said the study's senior author, Rob M. van Dam, an assistant professor at the Harvard School of Public Health in Boston.
Van Dam said that he and his colleagues believe that adiponectin isn't just a marker for a decreased risk of type 2 diabetes, but that the protein actually exerts a causal effect on the development of the disease. He said that in animal studies, when adiponectin is injected, metabolic differences occur. And, according to the study, adiponectin acts as a hormone with both anti-inflammatory and insulin-sensitizing properties.
That's important because in type 2 diabetes, the body often becomes resistant to insulin and doesn't use it effectively. Almost 24 million Americans have diabetes, and about 6 million of them don't yet know it, according to the U.S. Centers for Disease Control and Prevention. Untreated, the disease can lead to serious complications, including kidney failure, amputations and blindness.
What this study doesn't mean, however, is that you should add fat to increase your adiponectin levels. Fat tissue also produces other signaling molecules, according to van Dam, and most of these are destructive, not helpful. Additionally, although adiponectin is produced by fat tissue, the heavier you get, the less adiponectin you're likely to produce.
For the current study, he and his colleagues reviewed 13 studies in a meta-analysis. In all, they included almost 15,000 participants and 2,623 people who were diagnosed with type 2 diabetes.
All of the studies found a reduced relative risk of type 2 diabetes with higher levels of adiponectin. The average risk reduction was 28 percent for each incremental increase in adiponectin.
The researchers adjusted the data for body mass index and for lifestyle factors and found that the results were consistent across different ethnic groups, according to van Dam.
He said that adiponectin levels might eventually be used to predict who could develop type 2 diabetes, although much more research would be needed to ensure that this added new and accurate information to the risk assessment process.
Another practical implication that might eventually develop from these findings is a different type of medical intervention that would increase levels of adiponectin pharmacologically, van Dam noted.
For the moment, he said, "this study reinforces how important body fatness and adipose tissue is in the development of type 2 diabetes. Fat tissue is not just a storage organ that's just sitting there," he stated.
If you're concerned about preventing type 2 diabetes, van Dam said that losing just 5 to 10 percent of your body weight and maintaining that weight loss can have a big impact on your diabetes risk.
"This study is a really interesting observation, but everything that adiponectin is suggested to be doing could be attributed to less obesity," said Dr. R. Paul Robertson, president of medicine and science for the American Diabetes Association. "So, we don't know if there's a cause and effect relationship."
Robertson echoed van Dam's advice for preventing diabetes: "Avoid obesity." And if you're already overweight, try to lose weight. "So many things get better as you lose weight," he said.
Learn more about preventing type 2 diabetes from the American Diabetes Association.