AIMS/HYPOTHESIS: The potential impact of childhood bereavement-a severe psychological stressor-on childhood type 1 diabetes development remains unclear. Here, we aimed to bridge this knowledge gap and assess whether bereavement characteristics influenced any impact. METHODS: We conducted a register-based cohort study encompassing 3,598,159 children born in Sweden between 1987 and 2020. Childhood bereavement was defined as the death of a biological mother, father or sibling. Diagnosis of type 1 diabetes in childhood (<
18 years) was ascertained through the National Patient Register. We applied a Cox proportional hazards regression model to investigate the impact of childhood bereavement on type 1 diabetes, while adjusting for potential confounders (including parental type 1 diabetes status, country of birth and demographic characteristics). RESULTS: During follow-up, 86,226 children (2.4%) lost a family member, and 18,817 children (0.52%) were diagnosed with type 1 diabetes (median age at onset 9.1 years). We did not detect any overall association between childhood bereavement and type 1 diabetes (adjusted HR 1.04
95% CI 0.93, 1.17). We found no influence of age at loss, cause of death, familial relationship to the deceased, and time since loss. CONCLUSIONS/INTERPRETATION: In this large population-based Swedish study, we observed no evidence supporting a link between childhood bereavement and type 1 diabetes.