Bereavement in childhood and young adulthood and the risk of atrial fibrillation: a population-based cohort study from Denmark and Sweden.

BACKGROUND: Adverse childhood life events are associated with increased risks of hypertension, ischemic heart disease, and stroke later in life. Limited evidence also suggests that stress in adulthood may increase the risk of atrial fibrillation (AF). Whether childhood adversity may lead to the development of AF is unknown. We investigated whether the loss of a parent or sibling in childhood is associated with an increased risk of AF and compared this effect to that of similar losses in young adulthood. METHODS: We studied 6,394,975 live-born individuals included in the Danish (1973-2018) and Swedish Medical Birth Registers (1973-2014). We linked data from several national registers to obtain information on the death of parents and siblings and on personal and familial sociodemographic and health-related factors. We analyzed the association between bereavement and AF using Poisson regression. RESULTS: Loss of a parent or sibling was associated with an increased AF risk both when the loss occurred in childhood and in adulthood; the adjusted incident rate ratios and 95% confidence intervals were 1.24 (1.14-1.35) and 1.24 (1.16-1.33), respectively. Bereavement in childhood was associated with AF only if losses were due to cardiovascular diseases or other natural causes, while loss in adulthood was associated with AF not only in case of natural deaths, but also unnatural deaths. The associations did not differ substantially according to age at loss and whether the deceased was a parent or a sibling. CONCLUSIONS: Bereavement both in childhood and in adulthood was associated with an increased AF risk.