medwireNews: The age at diagnosis of type 1 diabetes has decreased substantially across successive generations, show study findings presented at the virtual 57th EASD Annual Meeting.
Kathleen Gillespie, from the University of Bristol in the UK, and team used data from the Bart’s Oxford family study to investigate changes in age at onset among 264 child and parent pairs who all had type 1 diabetes. The study has been registering people with diabetes diagnosed before age 21 years, and their families, since 1985.
Gillespie and team found that the children with diabetes were significantly younger than their parents when they were diagnosed, at a median of 9.5 versus 21.3 years, and a mean difference of 13.5 years.
However, to address the fact that “by definition parents are going to be older than their children,” the investigators repeated the analysis for 137 child and parent pairs with diabetes who were all diagnosed before the age of 21 years.
In this case, the median age at diagnosis was still lower among the children than their parents, at 9.0 and 13.0 years, respectively. Furthermore, 70% of children were younger than their parents when they were diagnosed, 3% were the same age, and 27% were older.
Gillespie also reported that the data reflect previously observed trends showing a difference in risk among children depending on whether their mother or father has diabetes.
Of the 137 child and parent pairs diagnosed before 21 years, 91 were cases where the father had diabetes compared with 46 pairs where the mother had diabetes.
The median ages at diagnosis of the fathers and their children were 13.0 and 9.0 years, respectively, while for mothers and their children the median ages were a respective 12.0 and 8.4 years. The corresponding mean differences were a significant 3.9 and 2.9 years.
“We feel that this reflects the decreasing age at diagnosis observed at the population level,” Gillespie remarked.
She noted that the team are now collaborating with other groups where the parents, rather than the children, were recruited and said that “the overall frequencies are almost exactly the same as we have observed in the Bart’s Oxford study, suggesting that this effect can be replicated across different cohorts.”
When asked by the session chair Tomasz Klupa (Jagiellonian University, Krakow, Poland) to speculate on how this phenomenon can be explained, Gillespie said that “these families are really enriched for HLA class 2, so they are very, very high-risk families and I guess the fact that we are seeing more children diagnosed earlier in [this] cohort, as we are in the general population, does suggest that it is a combination of genetic risk but with increased environmental pressure [but] it is very difficult to define what that increased environmental pressure is coming from.”
She also pointed out that they do not have BMI data but this “would be very interesting to look at.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2021 Springer Healthcare Ltd, part of the Springer Nature Group