New research shows that the early death of a sibling is associated with a 17% increased risk of cardiovascular disease, mostly early onset. The findings highlight the profound impact of bereavement on heart health and the need for additional support for grieving siblings to reduce the risk of future health problems.
The relationship between siblings is one of the longest-lasting and most intimate relationships, with a unique and profound impact on each other's development during childhood and adolescence. Previous research has shown that the loss of a sibling is a highly traumatic event that may be more devastating than the loss of other family members. But are there physical consequences to losing a sibling, such as an increased risk of disease?
To answer this question, researchers from Fudan University in China examined the relationship between sibling death in early life and subsequent cardiovascular disease (CVD) risk.
The researchers conducted a population-based study of more than 2 million Danes, 51.3% of whom were male, whose siblings died at a median age of 11.48 years. The study results show that premature cardiovascular disease refers to the first occurrence of cardiovascular disease before the age of 41. During a median follow-up of 17.52 years, 1,286 people in the bereaved group and 76,862 people in the non-bereaved group were diagnosed with cardiovascular disease. The median age of onset of cardiovascular disease is 22.86 years.
The overall risk of cardiovascular disease in bereaved people is 17% higher than in non-bereaved people. The researchers found that participants who lost a sibling had a 34% to 66% higher risk of heart failure, myocardial infarction, ischemic heart disease, pulmonary embolism and cerebrovascular disease than those who did not lose a sibling. The risk was increased whether a sibling died from cardiovascular disease or from noncardiovascular disease, but the risk was higher for most specific types of cardiovascular disease if a sibling died from cardiovascular disease.
Regarding the age difference between siblings, the correlation was stronger among participants who lost a twin or a younger sibling. The increased risk of cardiovascular disease after sibling death is observed in both the short and long term, regardless of age at the time of bereavement. However, the researchers noted that the risk of cardiovascular disease more than tripled in the first year after a sibling died in adolescence.
"In this cohort study, sibling death in childhood and early adulthood was associated with an increased risk of overall and most type-specific premature cardiovascular disease, with the strength of these associations varying by cause of death and age differences between siblings. This risk was highest soon after bereavement, especially in adolescents, but persisted long-term," the researchers said.
To the researchers' knowledge, this is the first population-based study to comprehensively reveal the association between sibling death and overall and specific types of cardiovascular disease risk. They proposed several mechanisms that might explain this association.
They found that individuals whose siblings died from cardiovascular disease had a higher risk of cardiovascular disease, supporting the hypothesis that shared genetic and environmental cardiovascular risk factors present in families may be an explanation. However, this risk also exists when siblings die from non-cardiovascular causes, suggesting factors other than genetics are at play. Psychological stress following bereavement may activate acute stress responses, leading to long-term pathophysiological changes. The heightened grief experienced after the loss of a twin or younger sibling may result in unusual psychophysiological states and abnormal cardiovascular health outcomes.
While this study does not directly prove that losing a sibling causes heart disease, the findings highlight the need for additional attention and social and mental health support for those who have lost a sibling to reduce the risk of cardiovascular disease later in life.
The study was published in JAMA Network Open.