Scientists at the University of Pennsylvania have identified a hormone that is released by fat cells and that interferes with the activity of insulin, causing type 2 diabetes. The hormone, which they named 'resistin' for 'resistance to insulin,' occurs at higher levels in obese individuals than in those with normal weight, according to animal studies reported in the January 18, 2001, issue of the journal Nature.

Researchers identified resistin in the blood of normal mice; it rises after eating. When they gave the mice recombinant resistin, glucose tolerance was impaired, blood levels of glucose rose, and the mice eventually developed the symptoms of diabetes. When they gave obese mice an anti-resistin antibody, their blood sugar levels and insulin action improved. And when they gave them an anti-diabetes drug, the levels of resistin decreased.

The hope for practical application of this finding is to develop drugs for people that would block or deactivate resistin, breaking the link between obesity and diabetes.