A new study suggests children under 15 could be more likely to develop type 1 diabetes in winter, reveals leading health charity Diabetes UK.
Analysis of data of 31,000 children from 105 diabetes centres across 53 countries found a correlation between the season and the onset of type 1 diabetes. Of the 42 centres that exhibited this seasonal trend, 28 had peaks of diagnosis in winter and 33 had troughs in summer.
The study, published in the journal Diabetic Medicine, also found that diabetes centres further away from the equator were more likely to have greater numbers of new cases in winter. This winter trend was more prevalent in boys as well as in both sexes from the older age groups (5-14 years old).
Victoria King, Diabetes UK Research Manager, said: "Results from previous studies in this area have been conflicting but this larger study shows a stronger correlation which is interesting, especially as we still don't know exactly why type 1 diabetes develops.
"Investigating why we might be seeing this pattern could tell us more about what may be triggering the development of type 1 diabetes. Despite this, the study looked at correlations over a relatively short period of time and not all centres that took part in the study showed the correlation between seasonality and diagnosis of type 1 diabetes so more data are needed before more definite conclusions can be drawn."
Lead author of the study, Elena Moltchanova, Statistician at the National Institute for Health and Welfare, Helsinki, said: "Numerous reasons have been suggested for the apparent seasonality of the onset of type 1 diabetes.
"These include a seasonal variation in people's levels of blood glucose and insulin, seasonal viral infections, the fact that young people tend to eat more and do less physical activity during winter months and, similarly, that summer holidays provide a rest from school stress and more opportunity to play outdoors."
Type 1 diabetes develops if the body is unable to produce any insulin. This type of diabetes usually appears before the age of 40. Type 1 diabetes is the least common of the two main types, accounting for between 5 and 15% of all people with the condition but almost all cases in children.
You cannot prevent type 1 diabetes and the condition develops when the insulin-producing cells in the pancreas have been destroyed. It is not known for sure why these cells have been damaged but the most likely cause is an abnormal reaction of the body to the cells. This may be triggered by a viral or other infection.