GDF15 and hypertensive disorder: Thirty-two instrumental variables for five metformin targets (i.e., AMP-activated protein kinase (AMPK), growth differentiation factor 15 (GDF15), mitochondrial glycerol 3 (MG3), mitochondrial complex I (MCI), and glucagon (GCG)) were introduced to the MR analysis on the datasets of hypertension, systolic and diastolic blood pressure (SBP and DBP).