Dang Wei, Imre Janszky, Fang Fang, Hua Chen, Rickard Ljung, Jiangwei Sun, Jiong Li, Krisztina D. Laszlo
Abstract
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.
Introduction
An increasing number of studies have suggested that the death of a spouse in middle and old age may increase the risk of cardiovascular mortality [1–4], particularly in the months following the loss [1,3]. Knowledge about the effect of bereavement on incident cardiovascular diseases (CVDs) and of other types of losses is much more limited, though recently, a few studies have reported associations between the death of a spouse, a sibling, a child, or “a significant person” and increased risks of acute myocardial infarction (AMI), stroke, atrial fibrillation, and/or cardiovascular mortality [5–11].
As one of the most extreme forms of bereavement [12], the death of a child is considered a “catastrophic stressor” and is rated 6 on a 6-step scale by a widely used classification system of sources of stress [13]. Accepting the loss of a child—a task that according to several theories of bereavement is the most important for grief resolution—is very difficult for parents [14], as child mortality is very low in Western societies and is in sharp contrast with expectations about the life cycle.
Discussion
We found that the death of a child was associated with an increased risk of IHD and AMI. The associations were present not only when the loss was due to CVD or other natural causes, but also in case of unnatural deaths. The risks of IHD and AMI were slightly higher after loss of an infant or an adult child and if the parent had 3 or more remaining live children, compared with other losses. The risk of AMI was highest in the first week after the loss, but a modestly increased AMI risk persisted throughout the follow-up.
Conclusion
We found that the death of a child was associated with an increased risk of IHD and AMI. The findings 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, and that the risk of AMI was highest during the week after the loss suggests that stress-related mechanisms may contribute to the observed association. Our findings, if confirmed, call for intensive surveillance and early intervention from the healthcare system among bereaved parents, particularly during the first week after the loss of a child.
Citation: Wei D, Janszky I, Fang F, Chen H, Ljung R, Sun J, et al. (2021) Death of an offspring and parental risk of ischemic heart diseases: A population-based cohort study. PLoS Med 18(9): e1003790. https://doi.org/10.1371/journal.pmed.1003790
Editor: Sanjay Basu, Harvard Medical School, UNITED STATES
Received: February 9, 2021; Accepted: September 1, 2021; Published: September 29, 2021
Copyright: © 2021 Wei et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All the data used in the present study were obtained from the Swedish National Board of Health and Welfare (https://www.socialstyrelsen.se/en/about-us/contact-us/), Statistics Sweden (https://www.scb.se), and Statistics Denmark (https://www.dst.dk/en/kontakt). The data cannot be shared publicly due to the Danish and Swedish relevant laws and regulations and due to ethical considerations. The data may be requested for research purposes from the above data holder authorities by researchers who fulfill specific requirements.
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.
Competing interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: KDL received research grants from the Swedish Council for Working Life and Social Research, the Swedish Heart and Lung Foundation, the Karolinska Institutet’s Research Foundation, the Clas Groschinsky Memorial Foundation and the Swedish Society of Medicine during the past five years. RL is employed at the Swedish Medical Products Agency, Uppsala, Sweden. The views expressed in this paper do not necessarily represent the views of the Government agency. The remaining authors have nothing to disclose.
Abbreviations: AMI, acute myocardial infarction; CI, confidence interval; CVD, cardiovascular disease; ICD, International Classification of Diseases; IHD, ischemic heart disease; IR, incidence rate; IRR, incidence rate ratio; MBR, Medical Birth Register; SD, standard deviation; STROBE, Strengthening the Reporting of Observational Studies in Epidemiology guidelines.
