Children are twice as likely to have type 1 diabetes if their father has the condition than if their mother does, research has highlighted.
A new study indicates that children may be offered long-term protection against type 1 diabetes if they are exposed to it in the womb through having a mother with the condition, compared to children whose fathers have type 1 diabetes.
Gaining an understanding into how this relative protection works, and the processes behind it, could help to develop preventative measures for the condition, researchers say.
Lead researcher Dr Lowri Allen, from the Diabetes Research Group at Cardiff University, explained: “Individuals with a family history of type 1 diabetes are eight to 15 times more likely to develop the autoimmune condition – however, studies have shown the risk is higher if the affected relative is the father rather than the mother. We wanted to understand this more.
“Previous studies have suggested that maternal type 1 diabetes is associated with relative protection against type 1 diabetes in offspring during early life. We wanted to know if this relative maternal protection from type 1 diabetes is confined just to childhood. We were also interested in what might be responsible for the effect.”
To explore this issue, the team conducted a meta-analysis of data from five studies of people with type 1 diabetes and their parents.
The studies included a total of almost 11,500 people, who were diagnosed with type 1 diabetes between the ages of 0 and 88.
The headline finding was that participants were 1.8 times more likely to have a father with type 1 diabetes than a mother with the condition, whatever the participants’ age of diagnosis.
This, the team says, “suggests the relative protection associated with having a mother versus father with type 1 diabetes is a long-term effect that extends into adult life”.
The relative protection offered by a mother having type 1 diabetes does not appear to be due to the genes inherited, as people with mothers with type 1 diabetes had similar genetic risk scores to those with fathers with type 1 diabetes.
What is important, however, is the age at which the participant’s parent is diagnosed with type 1 diabetes. The researchers found that someone was only more likely to have a father, as opposed to a mother, with type 1 diabetes if the parental diagnosis came before the child was born.
This means that the relative protection in having a mother with type 1 diabetes only appears to be a factor if she has the condition while pregnant.
Dr Allen explained: “This, coupled with the finding that the inherited genetic risk of type 1 diabetes was not different in individuals with affected mothers and fathers, suggests that exposure to type 1 diabetes in the womb is critical.
“Further research is needed to determine what it is about exposure to type 1 diabetes in the womb that is most important – is it exposure to high blood glucose levels, insulin treatment, antibodies associated with type 1 diabetes, a combination of these, or exposure to another aspect of type 1 diabetes?
“Understanding why having a mother compared with a father with type 1 diabetes offers a relative protection against type 1 diabetes could help us develop new ways to prevent type 1 diabetes, such as treatments that mimic some of the protective elements from mothers.
“Further research is needed but ultimately, we hope that it might be possible in the future to offer treatments at the very earliest stages of life to prevent the onset of type 1 diabetes in individuals who are at particularly high risk of the disease.”
The findings are being presented at the Annual Meeting of the European Association for the Study of Diabetes in Madrid in September.
