A particular genetic variant may help explain why some obese people do not develop type 2 diabetes (search) but some thin people do, according to new research.
Obesity is one of the major risk factors for developing type 2 diabetes. But not all obese people develop type 2 diabetes, and not all people with type 2 diabetes are obese.
The study shows that a variation in the gene ENPP1 is much more common in people with type 2 diabetes and those at greater risk for the disease. If further studies confirm these results, researchers say screening for this genetic difference may help identify those at risk of developing type 2 diabetes.
Researchers say the results may also partially explain why certain ethnic groups, such as people from India and South Asia, seem to have a higher risk of developing type 2 diabetes even when they are thin.
“The implication from our study is that if a person has this gene variation, then – without waiting for the development of insulin resistance – he or she should be encouraged to follow lifestyle changes that could help prevent the onset of diabetes,” says researcher Nicola Abate, MD, associate professor of internal medicine at the University of Texas Southwestern Medical Center, in a news release.
Type 2 diabetes occurs when cells become resistant to insulin in the body and not enough insulin is produced to maintain healthy blood sugar levels.
Researchers say the gene ENPP1 encodes a protein that blocks the action of insulin. But in people with a particular variant of this gene, the insulin-blocking action of the protein is increased.
Gene Linked to Diabetes Risk
In the study, which appears in the April issue of the journal Diabetes, researchers looked at the variations of ENPP1 in three groups: South Asians, South Asians living in Dallas, and whites living in Dallas. Some of the participants had type 2 diabetes, others had risk factors for the disease, such as obesity, and some showed no signs of diabetes risk factors.
The results showed that this ENPP1 variant was present in:
—34 percent of the South Asians living in India with type 2 diabetes vs. 25 percent of those without diabetes
—45 percent of the South Asians in Dallas with type 2 diabetes compared with 33 percent of those without the disease
—39 percent of the whites in Dallas with diabetes and 26 percent of those without the disease
“Consistently, we found that this gene variant in all three groups predicted diabetes,” says Abate.
Although further studies will be needed to confirm these results, researchers say having this genetic variant may predict a person’s susceptibility to type 2 diabetes in both South Asians and whites.
SOURCES: Abate, N. Diabetes, April 2005; vol 54: pp 1207-1213. News release, University of Texas Southwestern Medical Center.