A team of researchers at the Helmholtz Zentrum München, in Neuherberg, Germany, discovered that viral respiratory infections during the first six months of life increases the risk of type 1 diabetes (T1D). The study, “Infections in Early Life and Development of Type 1 Diabetes” was published in the May 3 issue of JAMA (Journal of the American Medical Association).
Viral infections, particularly by enteroviruses, had been hypothesized to cause T1D. Recent studies suggested that respiratory tract infections are associated with increased T1D risk if they occur within the first 6 months of life.
To investigate associations further, between infections in the first 2 years of life and the development of T1D, Prof. Dr. Anette-Gabriele Ziegler and colleagues conducted a population epidemiology study using data from 295,420 infants. Of those babies, 720 were diagnosed with T1D over a median follow-up of 8.5 years with incidence of 29 diagnoses per 100,000 children annually.
The team of researchers systematically examined all available data on infections with respect to the later development of T1D. The infections were classified according to the localization of the symptoms (such as eye, dermal, respiratory, or gastrointestinal infections), the causes (viral, bacterial, or mycoses) and age (quarter-yearly from birth).
“Our findings show that viral respiratory tract disorders during the first six months of life significantly increase the risk of children developing type 1 diabetes.” said Dr. Andreas Beyerlein in press release.
Infections that occurred later or that involved other organs were not statistically associated with a higher risk. The results from the study provide a step closer to understanding how T1D develops – with the interaction of environmental and genetic factors remaining unclear.
“Now for the first time we were able to confirm this in a population-based dataset of almost 300,000 children. In particular, we found strong indications that the first six months are an especially sensitive stage in life,” said Ziegler, the study’s lead scientist. “This is also consistent with other results that we have published based on data from children with increased familial risk, which already suggested that the first half-year of life is crucial for the development of the immune system and of autoimmune diseases such as type 1 diabetes.”
The team will now seek to determine if there is a causal association between early infections and T1D development, which pathogens play a contributing role, and how the pathogens affect the disease. Findings could serve as foundation for future development of a vaccine.
