Assessment of nitric oxide, advanced oxidation protein products, malondialdehyde, and thiol levels in patients with restless legs syndrome.

OBJECTIVES: We aimed to determine the importance of oxidative stress in the pathogenesis of restless legs syndrome (RLS) by quantification of advanced oxidation protein products and total thiol levels (as markers of oxidative protein damage), nitric oxide levels (as an antioxidant and endothelial function), and malondialdehyde levels (as a marker of lipid peroxidation) in patients with RLS. DESIGN AND METHODS: A total of 22 patients with primary RLS were enrolled in the study and 20 age-and-gender-matched healthy subjects were enrolled as a control group. Serum nitric oxide, malondialdehyde, thiol levels, and plasma advanced oxidation protein products levels were determined by spectrophotometric methods. RESULTS: Serum nitric oxide and thiol levels were lower in the patient group than in controls (p = 0.007 and p = 0.017, respectively). Plasma advanced oxidation protein products levels and serum malondialdehyde levels were found to be higher in patients with RLS than in controls (p = 0.017 and p = 0.008, respectively). Serum malondialdehyde level was found to be positively correlated with plasma advanced oxidation protein products levels (p = 0.039). Serum thiol level was found to be negatively correlated with plasma advanced oxidation protein products levels (p = 0.030). CONCLUSIONS: Increased advanced oxidation protein products, malondialdehyde levels, and decreased thiol and nitric oxide levels, may suggest that patients with RLS are under oxidative stress. Although both lipid peroxidation and protein oxidation may have a role in atherosclerosis in RLS, those factors may be related to the pathogenesis of RLS.

Assessment of paraoxonase 1, xanthine oxidase and glutathione peroxidase activities, nitric oxide and thiol levels in women with polycystic ovary syndrome.

OBJECTIVE: To investigate whether there is any relation between oxidative stress and the antioxidant system in the development of polycystic ovary syndrome (PCOS) by measuring serum nitric oxide (NO) levels and xanthine oxidase (XO) activity (a generator of reactive oxygen species) and antioxidant status by measuring serum thiol levels and glutathione peroxidase (GSHPx) and paraoxonase 1 (PON1) activities. DESIGN: Prospective case-control study. SETTING: University hospital in Turkey. SAMPLE: Thirty women with polycystic ovary syndrome and 20 age- and sex-matched healthy control subjects were included. METHODS: Serum XO, PON1 and GSHPx activity and NO and thiol levels were determined by spectrophotometric methods. MAIN OUTCOME MEASURES: Activity of serum XO, PON1 and GSH, as well as NO and thiol levels. RESULTS: Serum XO activities were higher in women with PCOS than in the control women (p<0.001). The PON1 activity was lower in women with PCOS than in the control women (p<0.001). No significant difference was found between NO and thiol levels and GSHPx activities of women with PCOS and the control women (p>0.05). Serum PON1 activities were negatively correlated with serum XO activities and NO levels. CONCLUSION: Increased oxidant XO activity and decreased lipid antioxidant PON1 activity, along with the observed negative correlation between these parameters, suggests that women with PCOS are under oxidative stress and that there is XO-mediated lipid peroxidation, which may be related to increased atherosclerosis seen in later life in such women.