Rise of type 1 diabetes may be linked to infections in infancy

by Barbara Hewitt on March 28, 2013

IDF launches Life for a Child campaign

Rise of type 1 diabetes may be linked to infections in infancy

Countries with lower mortality rate from infectious disease also have higher rates of type 1 diabetes, according to a new study suggesting that the condition may be linked to exposure to pathogens when young. Scientists used data from three major international studies to look for reasons why type 1 diabetes, which is caused when the immune system destroys the cells of the pancreas which release insulin, is increasing.

It is estimated to affect around half a million children worldwide, increasing by around 3% every year. This increase is well documented and is linked to the developed world but is so far unexplained. Various theories put forward include the hygiene hypothesis which suggests that encounters between the developing immune system and micro-organisms such as bacteria and parasites are part of human evolution and may therefore protect against the development of auto immunity.

The researchers investigated whether markers of infectious disease burden could be linked to the local incidence of type 1 diabetes. They used data from the World Health Organisation (WHO) DiaMond Project, WHO global burden of disease: 2004 update, and the Alexander Project, to correlate type 1 diabetes incidence by country. This was compared with mortality from infectious disease and bacterial antibiotic susceptibility, which indicates antibiotic use and thus exposure to bacterial infection.

Type 1 diabetes rates were highest in countries with low mortality from infectious disease. This was true for total mortality from infectious disease as well as deaths caused specifically by diarrhoea, respiratory disease, tuberculosis, and infections and parasitic disease. They also found type 1 diabetes rates are significantly associated with the local susceptibility of the bacteria Streptococcus pneumoniae to all antibiotics studied.

Study leader Professor Stephen Fava, consultant in diabetes and endocrinology at Mater Dei Hospital and Associate Professor of medicine at the University of Malta, said his team is keen to use further studies to identify other environmental factors which may predispose people to type 1 diabetes.

‘The global rise in type 1 diabetes is an unexplained phenomenon. Many suggest that the exposure, or rather the lack of exposure, to infectious disease when young might be linked to the development of autoimmunity,’ he said. ‘Our data show that type 1 diabetes rates were highest in countries where markers of exposure to infectious disease were lowest. Incidence of type 1 diabetes was significantly linked to mortality from a variety of infectious diseases and to the local susceptibility of a common bacterium to antibiotics,’ he explained.

Quote from DiabetesForum.com : “I have been a type 1 diabetic for 20 years now. Diagnosed when I was a freshman in high school, I started out as the “perfect diabetic” so to speak.”

‘These data provide support for the notion that the immune system can somehow become disordered and attack the body’s own cells if it is not trained by regular exposure to micro-organisms, the so called hygiene hypothesis. More research is needed to try to identify other environmental factors that may be linked to the continuing conundrum of rising type 1 diabetes rates,’ he added.

He also pointed out that whilst the data provides support for the hygiene hypothesis it does not prove it. The rise in type 1 diabetes rates is a complex problem and this study is of association only. Other potential contributing factors may show a similar geographical variation to infectious disease burden, as this is linked to the developed world,’ he said.


The opinions expressed in this article do not necessarily reflect the views of the DiabetesForum.com Community and should not be interpreted as medical advice. Please see your doctor before making any changes to your diabetes management plan.

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