The most common MetS parameter was arterial hypertension (76.6%), which correlated with GFR and creatinine; hypertriglyceridemia (47.8%), which is correlated with anti-ds-DNA Ab, erythrocyturia, proteinuria, and SLEDAI/r index; decreased HDL cholesterol (28.4%) which significantly correlated with albumin, C3 and anti-ds-DNA Ab. The gene discussed is C3; the disease is hypertriglyceridemia.