Association between education and blood lipid levels as income increases over a decade: a cohort study

BACKGROUND: Cardiovascular risk factors have increased along with economic development, but it is not clear if this tendency differs by education. The aim of this study was to analyze the effect of education on blood lipid levels while income increases over a decade in Chilean adults. METHODS: A cohort study was conducted from 3092 births in Limache Hospital between 1974 and 1978, of which 998 people were randomly selected in 2000 and 650 followed up in 2010. Using mediation analysis, the controlled direct effect (CDE) of education in 2000 on blood lipid levels in 2010: triglycerides (TG), total cholesterol (TC), LDL cholesterol (LDL) and HDL cholesterol (HDL) while setting the mediator, income, to “increased” between 2000 and 2010 was estimated. The results were expressed through the CDE and its 95% confidence interval (CI). RESULTS: Of the 650 adults, 24% had low education (≤ 8 years) and 60% increased their income. The mediation analysis showed that, when setting income to “increased”, women with low education had worse lipid profiles than women with high education: TG(CDE) = 14 (CI = − 7;34), TC(CDE) = 4 (CI = − 8;15), LDL(CDE) = 1 (CI = − 8;9), HDL(CDE) = − 3 (CI = − 7;0), while men with low education had better lipid profiles than men with high education: TG(CDE) = − 2 (CI = − 41;38), TC(CDE) = − 12 (CI = − 29;5), LDL(CDE) = − 12 (CI = − 24;1), HDL(CDE) = 1 (CI = − 5;6). CONCLUSION: Faced with a rise in income, there was a trend to associate low education with worse lipid profiles in women and better lipid profiles in men.