A bidirectional causality between type 2 diabetes and hypertension in Korean general population: A Mendelian Randomization Study

We deeply validated if the bidirectional causality between type 2 diabetes and hypertension is concordance with a previous Europian study in Korean large biobank. Five MR methods were applied using the weighted genetic risk score from 91 and 68 variants extracted from the genome-wide association study (GWAS) of the large Korean biobank (p-value <1.0×10-8), including a 2-stage least squares (2SLS) regression method, inverse-variance weighted (IVW) method, 2 median-based methods (simple and weighted) and MR-Egger were used to assess the bidirectional causal association between fasting blood sugar (FBS) and systolic blood pressure (SBP) in the Korean population. Using the 2SLS regression method, we showed that FBS genetically 0.5 mmol/L elevation caused an increased 1.63 mm/Hg SBP (p=0.0070), and genetically determined 10 mm/Hg elevation of SBP caused an increased 0.63 mmol/L FBS (p<0.0001). That bidirectional causal relationship was particularly strong among men. Under the other four methods, bidirectional causality was found also, and there was no horizontal pleiotropy The bidirectional causality different from previous studies between type 2 diabetes and hypertension was proved in the Asian general population, and. The underlying detailed mechanisms remain to be elucidated.