Causal effects of education on chronic kidney disease: a Mendelian randomization study

BACKGROUND: Poor socio-economic status, including low education attainment, has been reported in chronic kidney disease (CKD) patients. We aimed to investigate the causal effects of education attainment on the risk of CKD. METHODS: The study was an observational cohort study including Mendelian randomization (MR) analysis. First, the clinical association between education attainment years as the exposure and prevalent CKD Stages 3–5 as the outcome was investigated by multivariable logistic regression in 308 741 individuals 40–69 years of age from the UK Biobank. MR analysis was performed with a previously reported genetic instrument from a genome-wide association meta-analysis of education attainment. Two-sample MR was performed with summary statistics for CKD in 567 460 individuals with European ancestry in the CKDGen genome-wide association meta-analysis. The findings were replicated by allele score–based MR in 321 260 individuals of white British ancestry in the UK Biobank with quality-controlled genetic data. RESULTS: Higher education attainment was significantly associated with lower adjusted odds for CKD in the clinical analysis {>17 years versus <16 years, adjusted odds ratio [OR] 0.910 [95% confidence interval (CI) 0.849–0.975]}. The causal estimates obtained by the inverse variance method in the two-sample MR indicated that higher genetically predicted education attainment causally reduced the risk of CKD [OR 0.934 (95% CI 0.873–0.999)]. Allele score–based MR also supported that higher education attainment was causally linked to a decreased risk of CKD [adjusted OR 0.944 (95% CI 0.922–0.966)]. CONCLUSION: The study suggests that higher education attainment causally reduces the risk of CKD development in the general population.