The novel hormone is manufactured in the pancreas and researchers found it could stimulate new insulin production in rats and protect key insulin-producing cells from destruction.
Researchers from Duke University Medical Centre in North Carolina believe the discovery could lead to new preventive therapy and treatments for diabetes.
Their study was published in the journal Cell Metabolism.
The team identified a hormone called TLQP-21 inside beta cells, a type of islet cell within the pancreas that produces insulin to regulate blood glucose levels.
To test its properties, they gave the hormone to rats predisposed to type 2 diabetes and saw marked improvements in both insulin production and blood glucose levels. Fewer beta cells died in treated animals.
Lead author Dr Christopher Newgard and colleagues said: ‘We think this finding is important because it is the first demonstration that TLQP-21 prevents deterioration of the beta cells and stimulates insulin secretion in the presence of glucose.’
He added: ‘Because diabetes starts to take hold when the number of beta cells dwindles and insulin production drops, finding the best way to produce more of this protective hormone could be valuable.’
The hormone acts in a similar way to glucagon-like peptide-1 (GLP-1), which is already targeted by existing type-2 diabetes drugs.
However, researchers said that unlike these drugs the new hormone did not show side-effects of raised heart rate and digestion problems.
Researchers now plan to test the hormone in type 1 diabetes.