Death of an offspring and parental risk of ischemic heart diseases: A population-based cohort study

PLoS Med. 2021 Sep 29;18(9):e1003790. doi: 10.1371/journal.pmed.1003790. eCollection 2021 Sep.

Abstract

Background: The death of a child is an extreme life event with potentially long-term health consequences. Knowledge about its association with ischemic heart diseases (IHDs) and acute myocardial infarction (AMI), however, is very limited. We investigated whether the death of an offspring is associated with the risk of IHD and AMI.

Methods and findings: We studied parents of live-born children recorded in the Danish (1973 to 2016) and the Swedish (1973 to 2014) Medical Birth Registers (n = 6,711,952; mean age at baseline 31 years, 53% women). We retrieved information on exposure, outcomes, and covariates by linking individual-level information from several nationwide registers. We analyzed the abovementioned associations using Poisson regression. A total of 126,522 (1.9%) parents lost at least 1 child during the study period. Bereaved parents had a higher risk of IHD and AMI than the nonbereaved [incidence rate ratios (IRRs) (95% confidence intervals (CIs)): 1.20 (1.18 to 1.23), P < 0.001 and 1.21 (1.17 to 1.25), P < 0.001, respectively]. The association was present not only in case of losses due to CVD or other natural causes, but also in case of unnatural deaths. The AMI risk was highest in the first week after the loss [IRR (95% CI): 3.67 (2.08 to 6.46), P < 0.001], but a 20% to 40% increased risk was observed throughout the whole follow-up period. Study limitations include the possibility of residual confounding by socioeconomic, lifestyle, or health-related factors and the potentially limited generalizability of our findings outside Scandinavia.

Conclusions: The death of an offspring was associated with an increased risk of IHD and AMI. The finding that the association was present also in case of losses due to unnatural causes, which are less likely to be confounded by cardiovascular risk factors clustering in families, suggests that stress-related mechanisms may also contribute to the observed associations.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Attitude to Death
  • Bereavement*
  • Cause of Death
  • Child
  • Child, Preschool
  • Denmark / epidemiology
  • Fathers*
  • Female
  • Humans
  • Incidence
  • Infant
  • Male
  • Mothers*
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / epidemiology*
  • Myocardial Ischemia / diagnosis
  • Myocardial Ischemia / epidemiology*
  • Registries
  • Risk Assessment
  • Risk Factors
  • Sweden / epidemiology
  • Young Adult

Grants and funding

KDL was supported by the Swedish Council for Working Life and Social Research (grant no. 2015-00837), the Karolinska Institutet’s Research Foundation (grants no. 2018-01924) and the Swedish Heart and Lung Foundation (grant no. 20180306). DW was supported by the China Scholarship Council (grant no. 201700260276). IJ was supported by the Karolinska Institutet’s Research Foundation (grants no. 2018-01547 and 2020-01600). JL was supported by the Novo Nordisk Foundation (grant no. NNF18OC0052029), the Nordic Cancer Union (grant no. R275-A15770), the Danish Council for Independent Research (grants no. DFF-6110-00019B and 9039-00010B), and the Karen Elise Jensens Fond (grant no. 2016). FF was supported by Senior Researcher Award at Karolinska Institutet and Strategic Research Area in Epidemiology at Karolinska Institutet. HC was supported by the China Scholarship Council (grant no. 201700260296). JS was supported by the China Scholarship Council (grant no. 201700260278). The funders had no role in study design, data collection, data cleaning, data analysis, data interpretation, or writing of the report.