Systemic markers of oxidative stress in relation to metabolic syndrome components

The potential role of oxidative stress (OS) in metabolic syndrome (MetS) is rapidly evolving. Reported results support the concept that increased OS may play a key role in the development of atherosclerosis, hypertension and diabetes.

The purpose of this study was to analyze the clinical correlates of systemic OS markers in a well characterized group of patients with MetS.

72 hospitalized patients with a mean age 59.19+/-5.26 years were studied between October 2010 and June 2011. MetS was diagnosed based on the AHA/NHLBI/IDF 2009 definition. OS was assessed by urinary 8-isoprostaglandinF2α (8-isoPGF2α) (immunometric assays) and plasmatic uric acid (UA). Antioxidant status was evaluated by plasmatic glutathione peroxidase (GPx). These data were compared to those of 100 subjects without MetS (mean age 59.93+/-4.7 years).

All biomarkers were significantly higher in MetS patients as compared with healthy individuals (p<0.05), except GPx which was significantly lower (p<0.001). GPx and UA were statistically significant correlated. In multivariate analysis 8-isoPGF2α concentrations were influenced by hypertension, fasting glucose and triglycerides, UA levels were directly influenced by hypertension, waist circumference, fasting glucose and triglycerides. GPx levels were inversely correlated with blood pressure (all p<0.05). Only GPx was influenced by the number of MetS components. Subjects with a lower level of GPx had a significantly greater risk of MetS (OR 0.85).

Higher 8-isoPGF2α and uric acid and lower GPx levels are associated with MetS. The OS biomarkers are differently influenced by each component of the MetS. High blood pressure seems to be the key component linking OS to MetS. Antioxidant status is influenced by the number of MetS components with GPx being a risk factor for MetS.