Latitudinal gradient in childhood diabetes

New research from Perth's Telethon Kids Institute has shown the local relevance of a worldwide pattern of increased risk of childhood type 1 diabetes the further you live from the Equator.

The findings have been published in the journal Health and Place.

Researchers looked at childhood type 1 diabetes in Western Australia between 1991 and 2010 and found that the rate was twice as high in the south of Western Australia than in the north.  

Study author and spatial epidemiologist Dr Stephen Ball said the study strengthens the case that latitude is an important predictor of type 1 diabetes.

"Our results show a latitudinal gradient that was independent of other possible risk factors, namely socioeconomic status, population density, remoteness and ethnicity," Dr Ball said.  

"If we can better understand the causes for this pattern, we might be able to reduce the incidence of type 1 diabetes," Dr Ball said.

Diabetes clinician and Telethon Kids researcher Dr Elizabeth Davis said a possible explanation for the results is that people who live further from the Equator may have reduced skin exposure to sunlight, or different exposure to other environmental influences such as infections.

"These people may miss out on some of the health benefits of safe levels of ultraviolet radiation, such as the production of vitamin D," Dr Davis said.  "High levels of vitamin D deficiency in the Australian population suggest this might be a factor."

However, Dr Davis said it was important that anyone concerned about the health benefits of exposure to ultraviolet radiation consult current guidelines on safe levels of exposure.

Type 1 diabetes is a growing health problem worldwide.  While there have been big advances in the treatment of this disease, it remains a serious condition, with a long-term trend of 2-3% increased incidence per year throughout the world.  

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