The effect of nebivolol treatment on oxidative stress and antioxidant status in patients with cardiac syndrome-X

BACKGROUND: Free radical-mediated oxidative stress has been implicated in the etiopathogenesis of several disorders. The aim of this study was to elucidate the effect of treatment with nebivolol on the metabolic state of oxidative stress, and antioxidant status markers in patients with cardiac syndrome-X (CSX), additionally, to compare with the effect of metoprolol treatment. METHODS: Thirty patients, 17 female and 13 male, with CSX were enrolled in the study. Nebivolol (5 mg/day) or metoprolol (50 mg/day) was administrated for 12 weeks. Twelve hour fasting blood samples, taken at the initiation and on the third month of therapy, were analyzed for the levels of malondialdehyde (MDA), nitrite+nitrate (NOx), and the activity of myeloperoxidase (MPO), superoxide dismutase (SOD). No patient presented additional risk factors for increased reactive oxygen species levels. RESULTS: Compared with sixteen control participants, patients with CSX had significantly higher activity of MPO and levels of MDA, but significantly lower SOD activity and levels of NOx before treatment. After treatment, MPO activity and MDA levels were significantly reduced; SOD activity and NOx levels were significantly increased with nebivolol but remained unchanged with metoprolol. CONCLUSION: We have shown that patients with CSX who taken nebivolol have lower serum MPO activity, levels of MDA and higher serum SOD activity, NOx levels when compared with metoprolol treatment. Exercise stress test parameters were also ameliorated in patients who had taken nebivolol in contrast to metoprolol. Nebivolol treatment may be a novel treatment strategy in cases with CSX in the future.