C3 and Hypertension: Univariate analysis of the training cohort revealed that the following 19 items were significantly related to IgAN (all P < 0.05): age, hypertension, hematuria, eGFR, 24-h urine protein and serum albumin, urea nitrogen, creatinine, uric acid, IgA, IgG, IgM, complement C3, IgA/C3 ratio, total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and hemoglobin.