Association between maternal education and blood pressure : mediation evidence through height components in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Abstract

Background: Maternal education influences skeletal growth and offspring adult blood pressure (BP). Height components are negatively associated with BP in high-income countries. Aim: To evaluate the association between maternal education and offspring adult systolic and diastolic BP (SBP/DBP), assessing whether different height components might mediate such an association. Subjects and methods: Simple mediation modelling was used to evaluate the maternal education-offspring SBP/DBP association, estimating the contribution of offspring height components, in a cross-sectional sample of 13 571 Brazilians aged 34-75 from the ELSA-Brasil study. Results: After full adjustment for confounders, and compared to participants whose mothers received low education, those whose mothers received high education, had on average, 0.2 mm Hg lower SBP (95% CI: -0.274, -0.132), as result of the link between maternal education and offspring adult height which, in turn, influenced SBP. Thus, 18-26% of the maternal education-SBP association occurred indirectly, through height, trunk and leg length, alternatively. Conclusions: Better maternal education might influence higher leg and trunk lengths in offspring, which in turn, might contribute to prevent higher BP in adults. The negative height-BP association reported in high-income countries is also present in a middle-income country with more recent economic development.