Recent research, to be presented at the Annual Meeting of the European Association for the Study of Diabetes (EASD) in Madrid, demonstrates a significant difference in the likelihood of children developing type 1 diabetes (T1D) based on whether the condition is present in their mother or father. The study, spearheaded by Dr. Lowri Allen from the Diabetes Research Group at Cardiff University, indicates that children are nearly twice as likely to develop T1D if their father has the condition compared to their mother.
Investigating the Protective Effect of Maternal T1D
This comprehensive study, the largest of its kind, suggests that in utero exposure to T1D may confer long-term protection against the condition when the mother is affected. Dr. Allen explains, "Individuals with a family history of type 1 diabetes are 8-15 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."
To explore this phenomenon, Dr. Allen, along with Professor Richard Oram from the University of Exeter Medical School and their colleagues in the UK, Sweden, and the US, conducted a meta-analysis of data from five major studies: BOX, Better Diabetes Diagnosis, TrialNet Pathway to Prevention Study, Type 1 Diabetes Genetic Consortium, and StartRight. This meta-analysis encompassed 11,475 individuals diagnosed with T1D between ages 0 and 88.
Findings from the Meta-Analysis
The results revealed that individuals were almost twice as likely (1.8 times more likely) to have a father with T1D than a mother with the condition. This finding held true regardless of whether individuals were diagnosed in childhood (≤18 years) or as adults (>18 years). Moreover, those with mothers who had T1D were diagnosed at a similar age to those whose fathers had the condition.
"Taken together, our findings suggest the relative protection associated with having a mother versus father with type 1 diabetes is a long-term effect that extends into adult life," Allen notes.
Genetic Risk Analysis
The research team employed a genetic risk score, incorporating over 60 genes linked to T1D, to compare the inherited genetic risk in individuals with affected mothers and fathers. The scores were similar, suggesting that the relative protection offered by maternal T1D was not due to inherited genes.
The timing of the parent's diagnosis also emerged as a crucial factor. The increased likelihood of a father rather than a mother having T1D was observed only if the parent was diagnosed before the individual's birth. Allen elaborates, "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."
Future Research Directions
"This study, the largest to investigate the risk of type 1 diabetes in individuals with affected mothers and fathers, has enriched our understanding of the differences in parental risk, relative maternal protection from type 1 diabetes and underlying mechanisms," says Professor Oram. The research indicates that in utero exposure to maternal T1D is a key factor, but further studies are necessary to pinpoint the specific elements—such as high blood glucose levels, insulin treatment, or T1D-associated antibodies—that contribute to this protective effect.
Allen emphasizes the potential implications of these findings: "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."
Though more research is needed, the insights gained from this study could eventually lead to novel preventative treatments administered at the earliest stages of life to those at high risk for T1D. "To date, just one drug has been licensed to delay the onset of type 1 diabetes, and whilst several studies are underway to develop other treatments, limited progress has been made in identifying treatments that can be offered before diabetes has even begun to develop," Allen concludes.
Investigating the Protective Effect of Maternal T1D
This comprehensive study, the largest of its kind, suggests that in utero exposure to T1D may confer long-term protection against the condition when the mother is affected. Dr. Allen explains, "Individuals with a family history of type 1 diabetes are 8-15 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."
To explore this phenomenon, Dr. Allen, along with Professor Richard Oram from the University of Exeter Medical School and their colleagues in the UK, Sweden, and the US, conducted a meta-analysis of data from five major studies: BOX, Better Diabetes Diagnosis, TrialNet Pathway to Prevention Study, Type 1 Diabetes Genetic Consortium, and StartRight. This meta-analysis encompassed 11,475 individuals diagnosed with T1D between ages 0 and 88.
Findings from the Meta-Analysis
The results revealed that individuals were almost twice as likely (1.8 times more likely) to have a father with T1D than a mother with the condition. This finding held true regardless of whether individuals were diagnosed in childhood (≤18 years) or as adults (>18 years). Moreover, those with mothers who had T1D were diagnosed at a similar age to those whose fathers had the condition.
"Taken together, our findings suggest the relative protection associated with having a mother versus father with type 1 diabetes is a long-term effect that extends into adult life," Allen notes.
Genetic Risk Analysis
The research team employed a genetic risk score, incorporating over 60 genes linked to T1D, to compare the inherited genetic risk in individuals with affected mothers and fathers. The scores were similar, suggesting that the relative protection offered by maternal T1D was not due to inherited genes.
The timing of the parent's diagnosis also emerged as a crucial factor. The increased likelihood of a father rather than a mother having T1D was observed only if the parent was diagnosed before the individual's birth. Allen elaborates, "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."
Future Research Directions
"This study, the largest to investigate the risk of type 1 diabetes in individuals with affected mothers and fathers, has enriched our understanding of the differences in parental risk, relative maternal protection from type 1 diabetes and underlying mechanisms," says Professor Oram. The research indicates that in utero exposure to maternal T1D is a key factor, but further studies are necessary to pinpoint the specific elements—such as high blood glucose levels, insulin treatment, or T1D-associated antibodies—that contribute to this protective effect.
Allen emphasizes the potential implications of these findings: "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."
Though more research is needed, the insights gained from this study could eventually lead to novel preventative treatments administered at the earliest stages of life to those at high risk for T1D. "To date, just one drug has been licensed to delay the onset of type 1 diabetes, and whilst several studies are underway to develop other treatments, limited progress has been made in identifying treatments that can be offered before diabetes has even begun to develop," Allen concludes.