GSTM1 and hypertensive disorder: Covariates selected by backward selection for model of ED visit included Age, systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), ALB, alanine aminotransferase (ALT), uric acid (UA), serum sodium (Na), serum potassium (K), serum phosphorus (P), hemoglobin (Hb), parathyroid hormone (PTH), ferritin, hypertension (HTN), coronary artery disease (CAD).