Researchers reversed glucose intolerance in mice by boosting levels of a naturally occurring metabolic chemical.

The team from Washington University School of Medicine in St Louis hope to launch a human study on the potential treatment soon.

What did researchers do?
The metabolic chemical nicotinamide adenine dinucleotide (NAD) is thought to be one of many mechanisms involved in mediating metabolic responses when food was scarce.

However, modern, calorie-rich diets may be overwhelming this mechanism and could be a factor in the current obesity and diabetes epidemic, researchers suggested.

To examine how this mechanism may affect glucose intolerance, researchers induced mice to develop type-2 diabetes by feeding them a high-fat diet. They found that these mice had lower NAD levels as a result.

Researchers then injected the mice with nicotinamide mononucleotide (NMN), a molecule that helps produce NAD. Subsequently, levels of NAD increased and females had normal glucose tolerance test results. Male mice had improved, but not yet normal, readings.

Among older mice who had naturally developed diabetes on a normal diet, those injected with NMN had improved glucose tolerance too, even after a single injection.

Study lead Dr Shinichiro Imai concluded: 'These are really remarkable results. NMN improves diabetic symptoms, at least in mice.'

Informing patients
Stimulating a natural metabolic mechanism reversed type-2 diabetes in mice. Researchers said human trials were planned. Diabetes UK said the research was a long way from producing a viable treatment.

Will the findings lead to new treatments?
Dr Imai believes the discovery is promising for people with diabetes because the mechanisms that NMN influences are similar in mice and humans. 'But whether this mechanism is equally compromised in human patients with type-2 diabetes is something we have to check,' he said.

He said plans were afoot to do this in 'the very near future'. But Dr Iain Frame, research director at Diabetes UK, said the research did not support the idea that type-2 diabetes will be cured or prevented by taking a simple pill.

'The research is at a very early stage and has shown some benefit in female mice with diabetes and less benefit in male mice. While promising, it would take an enormous leap of faith to assume a new pill will soon be available for people with, or at high risk of, type-2 diabetes.'