Quantifying the dose-response relationship between childhood family education levels and cardiovascular disease risk

OBJECTIVES: This study examined how average family education in early life relates to long-term risk of cardiovascular disease (CVD) and all-cause mortality. STUDY DESIGN: Cohort study. METHODS: We included 972,832 Norwegians born 1940 and 1959 with at least one registered sibling, linked to registries and surveys. Participants were followed from age 40 until death from any cause, emigration, or December 31, 2020. We calculated parental, sibling, and family educational indexes using average education levels. Cox models assessed the association with CVD and all-cause mortality and modification by own education. Sub-cohort analyses (n = 363,918 and n = 226,431) adjusted for CVD risk factors and cognitive ability, respectively. RESULTS: A graded association was observed between family education levels and CVD and all-cause mortality. Compared to the lowest education group, individuals in the highest had lower mortality risk: HR 0.43 (95 % CI: 0.40-0.46) for CVD and 0.55 (95 % CI: 0.54-0.57) for all-cause mortality. These associations were partly attenuated after adjustment for CVD risk factors and cognitive ability. Individuals with both high family and high own education had substantially lower risk of CVD (HR 0.25, 95 % CI: 0.22-0.28) and all-cause mortality (HR 0.35, 95 % CI: 0.34-0.37). CONCLUSION: Our findings demonstrate a graded relationship between average education levels within families and the risk of CVD and all-cause mortality. Considering the educational attainment of multiple family members provides a more comprehensive understanding of the impact of early life social determinants on health outcomes.