- A recent study examined the association between the number and relative age of siblings and the combined risk of fatal and non-fatal cardiovascular events.
- The results suggest that being part of a larger family with multiple siblings or being a second or third-born sibling could increase the risk of cardiovascular events.
- This is the first study looking at birth order and family size to also include the risk of non-fatal cardiovascular events.
Family history and lifestyle factors such as smoking and poor diet are well-established risk factors for cardiovascular disease, including coronary heart disease and stroke.
In addition to a family history of CVD largely influenced by genetic predisposition, there is also evidence showing that family structure, especially birth order but not family size, may influence the risk of death from cardiovascular disease.
However, only a few studies have looked at the impact of family structure on non-fatal cardiovascular events.
A comprehensive understanding of the impact of family structure on CVD risk requires the inclusion of fatal and non-fatal cardiovascular events.
A large observational study of people aged 30 to 58 at the start now shows that the number of siblings and birth order may influence the risk of total cardiovascular events over a 25-year follow-up period.
A team of researchers led by Professor Peter Nilsson from Lund University in Sweden conducted this study. Their findings appear in the newspaper BMJ open.
To obtain information on family structure, the researchers used the
The study included data from 1.36 million men and 1.32 million women aged 30 to 58 in 1990. They determined the risk of non-fatal and fatal cardiovascular events as well as total mortality. of these people using data from death and hospital discharge registers between 1990 and 2015..
Factors such as socioeconomic status, education level, marital status, and medical conditions such as diabetes can influence CVD risk.
The team adjusted their analysis to account for the influence of these variables and isolate the impact of family structure on cardiovascular events.
Regarding family size, men and women with more than one sibling had a lower risk of death than those without siblings.
Men with one or two siblings had a lower risk of cardiovascular events than those without siblings, while those with four or more siblings had a higher risk.
Men with three or more siblings also had a higher risk of coronary events compared to no siblings.
Likewise, compared to women without siblings, women with three or more siblings had a higher risk of cardiovascular events. Additionally, women with two or more siblings had a higher risk of coronary events.
In the case of birth order, firstborns had a lower risk of cardiovascular and coronary events than those born later.
In contrast, firstborns had a higher risk of overall mortality than secondborn siblings.
The researchers point out that “more research is needed to understand the links between the number of siblings and rank with health outcomes.”
While the strengths of the study included a large sample size and comprehensive data on family structure and hospital records, it also had some limitations.
The researchers note that the study, due to its observational design, only shows a correlation between family structure and cardiovascular events and does not establish causation.
Due to lack of data, researchers were also unable to account for variables such as diagnostic procedures, parents’ socioeconomic status, smoking, diet and other related factors. lifestyle that might have influenced their assessment of CVD risk.
Since social factors are likely to contribute to the impact of family structure on health outcomes, including cardiovascular risk, the study findings could influence public health policies.
Significantly, this study was carried out in Sweden, which has a generous social protection system. The authors observe that “this is of public health interest as different countries approve different policies to support families and the number of children.”
“Future research should aim to find biological or social mechanisms linking firstborn status to a lower risk of CVD, as our observational results indicate,” the authors state.