Children with type 1 diabetes are ten times more likely to have common enteroviruses that can cause respiratory, digestive and nervous system infections, according to an analysis published in the British Medical Journal.
The authors of the study – scientists from the University of Sydney and the University of New South Wales in Australia – emphasize, however, that it does not prove that enteroviruses cause this type of diabetes. Therefore, further research is needed to understand the background of the observed compound.
Type 1 diabetes mellitus is classified as an autoimmune disease, i.e. it is caused by a false attack of immune cells on the body’s own cells. In this case, beta cells of the pancreas that produce insulin – the hormone that controls glucose metabolism – are destroyed. As a result, no insulin is produced and blood sugar levels rise dangerously. Therefore, in type 1 diabetes, insulin is administered from the beginning.
This disease accounts for about 10 percent. all cases of diabetes. It occurs mainly in children and adolescents.
The factors responsible for the development of type 1 diabetes are not fully understood. It is assumed to be the result of complex interactions between genetic, immunological and environmental factors.
In recent decades, there has been an increase in the number of cases of type 1 diabetes in the world, especially in children under the age of 5. In Europe, in the years 1989-2003, the incidence grew by 3,9% every year. This growth is too fast to be attributed to genetic factors, emphasize the authors of the article.
Therefore, environmental factors such as drugs, toxins, food ingredients and even infectious agents were suspected to be involved.
Epidemiological studies in recent years have suggested to scientists that viral infections could be partially responsible for this phenomenon. It is about infections with enteroviruses widespread in the environment, which include, for example, Polio and Coxackie viruses. Infections with them spread mainly through the gastrointestinal tract, and sometimes through droplets. Most infections caused by these viruses are asymptomatic. The most dangerous of these is the Polio virus, which can even cause meningitis, paralysis or severe encephalitis.
There were studies showing, among others, that enterovirus infections are more common among children who later develop autoimmune immune system against pancreatic beta cells or type 1 diabetes.
However, not all studies support this relationship.
Australian scientists analyzed 26 studies, which in total included almost 4,5 thousand. people. The presence of genetic material of enteroviruses (in the form of RNA) and viral proteins was checked in blood, stool and even tissue samples taken from them.
They found that enterovirus infection was 10 times more common in children with type 1 diabetes than in their healthy peers. In turn, in people with symptoms of an autoimmune reaction (the presence of specific antibodies) that can lead to this disease, these viruses were almost 4 times more common.
As the researchers point out, this does not at all prove that enteroviruses cause type 1 diabetes. Equally, people with diabetes may be more susceptible to infection with these viruses. Or maybe some genetic factors are responsible for both.
Therefore, further work is needed on this issue, the researchers note.
In addition, Dr. Alan Foulis from Glasgow Royal Infirmary, who did not participate in the study, comments that there are at least several dozen enteroviruses in the world, so scientists must check which exactly is related to diabetes. This would eventually allow the development of a vaccine against it. (PAP)