This cross-sectional study was performed in 15 hemodialysis patients who had severe and uncontrolled HPT (S-HPT) and had already been referred for parathyroidectomy. These patients were pair-matched for age and gender to a group of 15 clinically stable hemodialysis patients with mild to moderate HPT defined as PTH 3 mo. Patients with active infectious or inflammatory disease, patients who were hospitalized within 3 mo before the study, and those who were receiving steroids and/or immunosuppressive agents were excluded from the study. Eleven patients in the S-HPT group and 10 patients in the M-HPT were taking antihypertensive drugs (β-blockers: five patients in the S-HPT group and four patients in the M-HPT group).