Abstract
In this pathbreaking study, we evaluated nitrosative stress in morbidly obese patients with and without metabolic syndrome. 62 women with class 3 obesity (BMI > 40 kg/m(2)) were divided into three subgroups: obese patients (OB), obese patients with hypertension (OB+HYP), and obese patients with metabolic syndrome (OB+MS). In comparison to the lean patients, OB had increased levels of serum myeloperoxidase (MPO), plasma nitric oxide (NO), S-nitrosothiols, and peroxynitrite (ONOO(-)), as well as nitrotyrosine, while oxidized glutathione (GSSG) rose only in OB+HYP group. Interestingly, ONOO(-) was significantly higher in OB+HYP and OB+MS as compared to OB group, while MPO only in OB+MS group. OB+MS had greater nitrotyrosine and S-nitrosothiol values than OB+HYP. Moreover, peroxynitrite could differentiate OB from OB+HYP and OB+MS (AUC 0.9292; p < 0.0001; 87.5% sensitivity, 90% specificity) as well as between OB and OB+MS group (AUC 0.9125; p < 0.0001; 81.25% sensitivity, 83.33%). In conclusion, we showed that MPO activity, NO formation, and nitrosative damage to proteins parallel the progression of metabolic disturbances of obesity. Evaluation of ONOO(-) concentrations may help predict the development of hypertension and metabolic syndrome in patients with morbid obesity; however, longer-term studies are required for larger numbers of patients.