Causal relationship between educational attainment and complications of Type 2 diabetes: Mendelian randomization study

Educational attainment (EA) is a critical metric for evaluating individual socioeconomic status, as it significantly impacts mortality rates and the occurrence of various diseases. This study aims to investigate the causal relationship between education and complications associated with type 2 diabetes mellitus, while also examining potential mediating pathways. To assess the causal relationship between EA and specific complications of type 2 diabetes, this study employs univariable Mendelian randomization (UVMR). Throughout this analysis, single nucleotide polymorphisms are utilized as genetic tools, thereby minimizing confounding and bias arising from reverse causation. With each 4.2-year increase in EA, patients with type 2 diabetes exhibit a reduced risk of type 2 diabetes mellitus with neurological complications (DNC) (0.33; 0.20, 0.54), type 2 diabetes with ophthalmic complications (DOC) (0.57; 0.41, 0.80), type 2 diabetes with peripheral circulatory complications (DPCC) (0.60; 0.39, 0.93), and type 2 diabetes with renal complications (DRC) (0.47; 0.32, 0.69). Among the 27 candidate mediators, body mass index, waist circumference, and watching television showed relatively large mediation proportion point estimates for some outcomes. The findings of this study suggest that EA exerts a causally protective effect on DNC, DOC, DPCC, and DRC. The candidate mediating pathways warrant further investigation because their independent contributions have not been established.