Diabetes and virus link confirmed

Do viruses play a role in childhood diabetes?

Children with Type 1 diabetes are nearly 10 times as likely to also have a viral infection than healthy children, Australian research suggests.

Childhood diabetes has been linked to enteroviruses, which can lead to cold, flu and even meningitis.

However the review of 26 existing studies by a group in Australia, published in the BMJ, does not prove that the virus causes diabetes.

Diabetes UK said more research was needed to pinpoint the cause of Type 1.

The illness typically appears in childhood, when the pancreas stops producing the hormone insulin and the body cannot control the level of sugar in the blood.

More common

The number of cases has been increasing, without explanation, across the globe.

There is a genetic factor to Type 1 diabetes but this does not explain the rise, so scientists are searching for environmental factors.

One of these is thought to be the enterovirus, yet previous studies on the virus have been inconsistent.

Researchers at the University of New South Wales and the Institute of Endocrinology and Diabetes in Sydney combined the research of several groups to provide a more definitive answer.

They reviewed 26 sets of research involving 4,448 patients and concluded: "The association between enterovirus infection, detected with molecular methods, and diabetes was strong, with almost 10 times the odds of enterovirus infection in children at diagnosis of Type 1 diabetes.

Dr Jonathan Levy, consultant diebetologist at the Oxford Centre for Diabetes, Endocrinology and Metabolism, said: "It looks to be a very well conducted study that seems to nail the association very dramatically, especially in the newly diagnosed."

The root of the problem

One of the issues with this type of research is that it is hard to prove what causes what.

Enterovirus could cause diabetes, or diabetes could make you more susceptible to enterovirus - or something else, such as genetic makeup, could make you more likely to get both.

The authors acknowledge more studies need to take place.

Dr Iain Frame, director of research at Diabetes UK, said: "Many factors have been reported as being associated with Type 1 diabetes but that is not the same as causing Type 1 diabetes and this report based on looking at a number of previous studies does not bring us much closer to pinpointing the causes of Type 1 diabetes."

"We do, however, welcome any new analysis that brings about a better understanding of the involvement of certain viruses on the insulin-producing cells in the pancreas.

"It may well give us another piece of the jigsaw in working towards a better understanding of the causes of Type 1 diabetes which should in turn lead to new prevention strategies."

Dr Alan Foulis, who has been researching the link between diabetes and viruses at Glasgow Royal Infirmary, said: "There's evidence of enterovirus involvement, but there are too many different enteroviruses, hundreds of them."

"What researchers are trying to do is pool resources across Europe to find out which enteroviruses could be be associated with Type 1, which a vaccine manufacturer would need to know to pinpoint the exact one to target."