A group of common viruses closely related to type 1 diabetes

A new study presented at the annual meeting of the European Association for the Study of Diabetes in Stockholm, Sweden (September 19-23) found that a common group of viruses is strongly associated
with type 1 diabetes (T1D).

The Australian analysis found that people who carry the T1D gene are 8 times more
likely to be infected with enteroviruses than people without the T1D gene.

T1D is one of the most common forms of diabetes in children, and its incidence has been rising
globally in recent decades.

Over time, high blood sugar levels can damage the heart, eyes, feet, and kidneys and shorten life expectancy
.

Exactly what triggers an attack on the immune system is still debated, but it is thought to be related
to a combination of genetic predisposition and one or more environmental triggers, such as a viral infection.

Some of the strongest evidence of viral infection points to enteroviruses
.

Vaccines that attempt to reduce the incidence of T1D by preventing enterovirus infections have entered clinical trials1, and confirmation of the role of enteroviruses will support this and other T1D primary prevention efforts
.

To explore this link in greater depth, Sonia Isaacs of the Department of Pediatrics and Child Health at the University of New South Wales School of Clinical Medicine, Australia, and his colleagues conducted a systematic review and meta-analysis
of existing research on the topic.

The meta-analysis, the largest in the field, included data
from 12,077 participants (aged 0-87 years) in 60 controlled observational studies on the PubMed and Embase databases.

5981 participants had T1D or islet autoimmunity (usually progressing to T1D
).

Enterovirus RNA or proteins are markers of current or recent infections and are detected
in blood, feces, or tissue samples through a range of advanced and highly sensitive molecular techniques.

People with islet autoimmunity are twice as likely to test positive for enteroviruses as
people without islet autoimmunity.

Patients with T1D are 8 times more
likely to have enterovirus infection than patients without T1D.

On top of that, patients with T1D are more than 16 times more likely to detect an enterovirus infection within a month of diagnosis of T1D than
in patients without T1D.

The researchers concluded that there is a clear association
between enterovirus infection and islet autoimmunity and T1D.

Ms Isaacs added: "These findings provide further support for ongoing work to develop vaccines to prevent the development of islet autoimmunity, thereby reducing the incidence
of T1D.

There are several theories
about how enteroviruses increase the risk of developing T1D.
For example, it is thought that their interaction with specific genes may be important
.

Ms Isaacs explains: "Our study found that patients with T1D who were both at genetic risk and had a first-degree relative of T1D were 29 times more
likely to be infected with enteroviruses than other patients.

The number, time, and duration of enterovirus infection, and even the site of infection may also be important
.
The "leaky gut" hypothesis holds that viruses originating in the gut may move to the pancreas with activated immune cells, where low levels of persistent infection and resulting inflammation can lead to an autoimmune response
.

Viral infections are also thought to be linked to other factors, such as diet, imbalances in the gut microbiome, and possibly even chemical exposure
in the womb (during pregnancy) or early childhood.
There's still a lot to learn
.