Sibling rank and sibling number in relation to cardiovascular disease and mortality risk: a nationwide cohort study

Abstract

BackgroundThe number and rank order of siblings could be of importance for risk of cardiovascular disease and mortality. Previous studies have used only fatal events for risk prediction. We, therefore, aimed to use also non-fatal coronary and cardiovascular events in fully adjusted models.MethodsFrom the Multiple-Generation Register in Sweden, data were used from 1.36 million men and 1.32 million women (born 1932–1960), aged 30–58 years at baseline and with follow-up from 1990 to 2015. Mean age at follow-up was 67 years (range 55–83 years). Fatal and non-fatal events were retrieved from national registers.ResultsCompared with men with no siblings, those with 1–2 siblings had a lower, and those with four or more siblings had a higher adjusted risk of cardiovascular events. Again, compared with men with no siblings, those with more than one sibling had a lower total mortality risk, and those with three or more siblings had an increased risk of coronary events.Correspondingly, compared with women with no siblings those women with three siblings or more had an increased risk of cardiovascular events, and those with two siblings or more had an increased risk of coronary events. Women with one sibling or more were at lower total mortality risk, following full adjustment.ConclusionBeing first born is associated with a favourable effect on non-fatal cardiovascular and coronary events for both men and women. The underlying biological mechanisms for this should be studied in a sociocultural context.

Only children’s midlife health: Chronic disease indicators and biomarkers for three nationally representative UK birth cohort studies

“…Our findings are consistent with prior analysis of BMI trajectories by sibship size in the UK context, 13 but clearly in contrast with research showing worse health and higher mortality among individuals without siblings in Sweden, compared to those with siblings. 6,7,10 However, in Sweden only children appear to be a more select and more disadvantaged group than in the UK, which may explain the difference in findings and the poorer health outcomes for (adult) only children in Sweden remaining notable even after robust adjustment for potential confounders. The overall null finding in this study is important in the context of refuting persistent stereotypes of a universal only child disadvantage attributable to the experience of growing up in a family without siblings.…”

“…The limited studies on morbidity and mortality by sibship size suggest important variations across contexts. [6][7][8][9][10][11][12][13][14] On the one hand, research suggests higher risk of adverse health outcomes among only children. Two recent studies using Swedish data have found young men without siblings are more likely to have a body mass index (BMI) categorised as overweight or obese, and lower physical fitness, than individuals with siblings, 6 and that adult only children have higher risk of cardiovascular disease (but not coronary heart disease) compared with individuals with siblings.…”

“…Two recent studies using Swedish data have found young men without siblings are more likely to have a body mass index (BMI) categorised as overweight or obese, and lower physical fitness, than individuals with siblings, 6 and that adult only children have higher risk of cardiovascular disease (but not coronary heart disease) compared with individuals with siblings. 7 A systematic review and meta-analysis found only children were more likely to be classified as overweight or obese across a range of contexts (the review covered studies from Europe, Asia and the Americas, predominantly focused on adolescence). 8 A Finnish study found adult only children to have higher risk of hypertension than those with two or more siblings, higher risk of BMI above the obesity threshold than those with one sibling (adjusted for age and sex), and higher risk of high triglyceride among men who were only children than men with two or more siblings.…”

“…8 A Finnish study found adult only children to have higher risk of hypertension than those with two or more siblings, higher risk of BMI above the obesity threshold than those with one sibling (adjusted for age and sex), and higher risk of high triglyceride among men who were only children than men with two or more siblings. 9 Mortality risk has also been found to be higher in Sweden among only children, compared with those with siblings, including mortality attributable to circulatory problems, 6,7,10 and one study of Scottish university graduates found that men without siblings had higher respiratory disease mortality. 11 On the other hand, the same Scottish study found no association with all-cause mortality nor mortality attributable to coronary heart disease, stroke or stomach cancer, 11 while another study also using Scottish data found that men who grew up as only children had a lower risk of stroke mortality and lung cancer mortality than men with siblings.…”

Emerging Concepts in Innate Lymphoid Cells, Memory, and Reproduction

“…Conditions experienced during intrauterine life have a major impact on the development of chronic diseases later in life ( 122 , 123 ). In connection, multiparity, birth order, and interpregnancy interval are associated with pregnancy outcome as well as health in childhood and adulthood ( 124 – 127 ). Distinct biological factors have been proposed to explain these phenomena.…”