The current study looks at how ARNT might be affecting the liver, and its results confirmed Dr Gunton's suspicions. "We've shown that there's likely to be decreased ARNT in the liver of people with Type 2 diabetes compared to people without Type 2 diabetes," she said.

"Working with mice, we found that glucose levels were elevated and there was glucose production from a 'precursor', a source not normally metabolised."

Other results in the study show that to some extent ARNT is regulated by insulin, so that insulin resistance in itself will contribute to a decrease in ARNT. If liver cells are treated with insulin, there will be a small increase in ARNT protein. The insulin will also help move the ARNT into the nucleus of the cell, where it does its job as a master regulator.

The paper concludes that a decline in ARNT isn't limited to the beta cells of people with Type 2 diabetes. ARNT is also reduced in other important diabetes-related tissues like the liver.

Dr Gunton believes that if a new drug could be developed to increase ARNT activity in the liver, then it may be possible to shut down abnormal sugar production and improve blood sugar control in people with diabetes.

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