Stable heritability of type 1 diabetes in a Swedish Nationwide Cohort Study

PMCID: PMC12174315

PMID: 40527903

DOI: 10.1038/s41467-025-60813-2

Journal: Nature communications

Publication Date: 2025-6-17

Authors: Wei Y, Andersson T, Liu S, Feychting M, Kuja-Halkola R, et al.

Key Points

• T1D incidence nearly doubled between 1982-2000, with a hazard ratio of 1.85 (95% CI: 1.65, 2.08) for children born in 2000 versus 1982
• Heritability remained consistently high at 0.83, with genetic factors explaining approximately 83% of T1D variance
• The study suggests that current known environmental factors cannot fully explain the rising T1D incidence, indicating a need for further investigation into potential unidentified environmental triggers

Summary

This comprehensive nationwide Swedish cohort study investigated the changing epidemiology of childhood-onset type 1 diabetes (T1D) by analyzing data from 2,928,704 children born between 1982-2010. The research revealed a significant increase in T1D incidence from 1982 to 2000, with cumulative incidence rising from 0.50% to 0.93%, followed by a stabilization period from 2001-2010.

Critically, the study demonstrated that despite the rising incidence, the heritability of T1D remained remarkably stable at approximately 0.83 throughout the observation period. Extensive analysis of potential environmental factors showed that shifts in maternal, perinatal, and childhood factors explained less than 10% of the increased T1D incidence, suggesting that unknown environmental influences or complex gene-environment interactions may be driving the observed trends.