EPO and Hypertension: SD: standard deviation; HTN: hypertension; PWVb-a Right: pulse wave velocity brachial-ankle right side; PWVb-a Left: pulse wave velocity brachial-ankle left side; PWVc-f: pulse wave velocity carotid-femoral; MDA: malondialdehyde; NO: nitric oxide; EPO: erythropoietin; VEGF: vascular endothelial growth factor