Link Found Between Genes and Diabetes
Discovery pinpoints origin of weight gain, for some, that raises risk

(HealthDay News) -- Researchers have discovered a genetic variation that's linked to obesity and, as a result, type 2 diabetes.

People with this genetic variation weigh about 7 pounds more than people who don't have it.

"We have identified a common variant in the FTO gene that, by being associated with an increased body mass index [BMI], results in an increased predisposition to both obesity and type 2 diabetes," study co-author Dr. Andrew Hattersley, a professor of molecular medicine at Peninsula Medical School in Exeter, England, told HealthDay .

Although the finding certainly doesn't explain all overweight and obesity -- about one-sixth of the American population has this variation, according to the study -- it might provide new avenues for researchers to look for possible treatments.

The incidence of obesity has more than doubled in the past 30 years, according to the U.S. Centers for Disease Control and Prevention (CDC). In 2004, nearly 33 percent of Americans were obese. Excess weight can increase the risk of type 2 diabetes, high blood pressure, high cholesterol, heart disease, stroke, sleep apnea and some cancers, according to the CDC.

The additional weight caused by the FTO variant "increases the risk of obesity by approximately 67 percent and type 2 diabetes by about 40 percent," Hattersley said.

The study, which appeared in the journal Science , included data from 13 studies involving nearly 40,000 participants. The FTO variant was found to be associated with obesity in people older than 7 years of age.

The exact reason the genetic variant is associated with obesity isn't clear, but the study does show that genetic factors are important in the development of obesity, Hattersley said.

"These findings suggest a completely novel and unexpected pathway in the regulation of obesity, which might become a target for treatment of diabetes or obesity in the future," he said.

Yvon C. Chagnon, director of the Genomic Laboratory at Laval University Research Center in Quebec , told HealthDay that "the authors presented very convincing results of the possible association of the FTO gene with BMI, and more particularly the fat portion of BMI."

Chagnon added, "This gene will probably have multiple and unsuspected functions. This implies that there are numerous genes for a given complex trait such as obesity. FTO becomes a good example of this unexpected and completely new association of a gene with a biological trait."

However, he said, "it is obvious that many other genes should be involved in the control of BMI, as illustrated by the relatively low percentage of variance explained by FTO ."

On the Web

To learn if you're at risk for type 2 diabetes, visit the National Institute of Diabetes and Digestive and Kidney Diseases.

SOURCES: HealthDay News ; Andrew Hattersley, M.D., professor of molecular medicine, Peninsula Medical School, Exeter, England; Yvon C. Chagnon, Ph.D., director, Genomic Laboratory, Laval University Research Center, Quebec, Canada; April 12, 2007, Science ; U.S. Centers for Disease Control and Prevention (www.cdc.gov)
Author: Serena Gordon
Publication Date: April 30, 2008
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