Early-life factors play small role in adult-onset T1D

Research into type 1 diabetes (T1D) has focused primarily on children, as the disease is typically diagnosed before the age of 20 years. However, a recent study shows that the median age of onset is now 29. Data on adult T1D is limited, and adult-onset autoimmune diabetes often resembles type 2 diabetes, particularly latent autoimmune diabetes in adults (LADA). This variation suggests different causes and risk factors, but there is a lack of data on modifiable factors that influence the development of adult T1D and LADA.

T1D is thought to result from genetics and environmental factors, with a higher incidence in Nordic countries and associations with specific genetic markers. Environmental risks, such as diet and childhood infections, have been studied but without strong causal links. Perinatal factors such as maternal age, birth weight and preterm birth have been consistently associated with childhood T1D. The study aimed to assess adult-onset T1D and investigate whether the perinatal factors associated with childhood also apply to adults, using high-quality Swedish registers to minimise confounding by comparing siblings with different early life exposures.

The study identified 3,283 people diagnosed with adult-onset T1D and analysed their birth records to assess several early-life factors. The researchers found that a family history of diabetes, especially in the father, significantly increased the risk of developing T1D in adulthood. Women and those whose parents were born outside Sweden were less likely to develop T1D. In addition, those who were born prematurely had a slightly higher risk.

Overall, the study suggests that early life factors have less of an impact on the development of T1D in adulthood than the onset of the disease in childhood, suggesting that other triggers later in life are likely to be more important. These findings were also consistent when comparing siblings, reinforcing the conclusion that early-life factors play a minor role in adult-onset T1D.

First author of the study is Coralie Amadou, post doctoral researcher in the ESTRID group.

Publication

Early-Life Factors Associated With Adult-Onset Type 1 Diabetes: A Swedish Nationwide Cohort and Family-Based Study.
Amadou C, Wei Y, Feychting M, Carlsson S
Diabetes Care 2024 Jul;():