Effects of estrogen-only therapy on LDL oxidation in women with hysterectomy: does paraoxonase genotype play a role?

OBJECTIVES: This study investigated the effects of estrogen-only therapy on lipid profile (through susceptibility of low density lipoproteins to oxidation) and on oxidant-antioxidant parameters in surgical menopausal women. PON genotypes are also evaluated considering that they may be associated with the personal differences observed in antioxidant effects induced by estrogen. METHODS: Thirty women who had undergone hysterectomy+bilateral ovariectomy in the last 3 years, with causes other than malignancy were included and given estrogen-only (Premarin-Wyeth Inc. 0.625 mg/day/6 months, equine conjugated estrogen). Blood samples were collected at baseline, first and sixth month of treatment. Serum (total antioxidant activity-TAO and PON activity), erythrocyte (TBARS and catalase activity), LDL and Cu2+ induced ox-LDL (TBARS and diene levels) samples were evaluated and PON1 192 polymorphisms were determined by PCR amplification & restriction enzyme digestion. RESULTS: At the sixth month, a higher TAO activity (p=0.016) and a lower eTBARS (p=0.028) were detected compared to the basal values. LDL and Cu induced ox-LDL TBARS levels at the sixth month of treatment were significantly (p=0.012 and 0.026, respectively) lower compared to the pretreatment values. Baseline eTBARS (p=0.007), LDL TBARS (p=0.044) and eCAT (p=0.033) activities were significantly higher in homozygote Q allele carriers compared to subjects with R allele. LDL TBARS and Cu2+ induced ox-LDLTBARS of QQ subjects (p=0.018 and 0.050) as well as LDL TBARS of QR subjects (p=0.044) showed a significant decrease with estrogen-only treatment. CONCLUSIONS: Our study drives the attention to PON polymorphism in postmenopausal women who have risk for atherosclerosis. Although our data is limited, this study is the first that focuses on the role of PON genotypes in antiatherosclerotic effects of estrogen-only and provides important points for further studies.

A panel of oxidative stress assays does not provide supplementary diagnostic information in Behcet's disease patients.

BACKGROUND: Recent findings suggest a role of oxidative stress in the pathogenesis of Behcet's disease (BD), but the utility of oxidative stress-associated assays in offering diagnostic information or in the monitoring of disease activity is largely unassessed. OBJECTIVE AND METHODS: We aimed to measure oxidative and inflammatory markers, along with the markers of reactive nitrogen species, S-nitrosothiols and 3-nitrotyrosine, in BD patients (n = 100) and healthy volunteers (n = 50). These markers were evaluated in regard to their role in the pathogenesis of BD as well as their relation to clinical presentation, disease activity and duration. RESULTS: Median values for erythrocyte sedimentation rate (ESR), C-reactive protein, leukocyte count, and IL-18 levels, as well as myeloperoxidase (MPO) activity, were statistically higher in the patient group compared to controls. Some inflammation markers (ESR, neutrophil and leukocyte counts) were statistically higher (p < 0.05) in the active period. In contrast, oxidative stress-associated measures (erythrocyte lipid peroxidation, antioxidant enzymes and measures of serum antioxidant capacity), revealed no statistically significant differences between the median values in BD patients versus healthy control subjects (p > 0.05 in all statistical comparisons), nor was there any difference in median levels of these oxidative stress markers in active disease versus disease remission. S-nitrosothiols and 3-nitrotyrosine were undetectable in BD plasma. CONCLUSIONS: The application of oxidative stress-associated measures to BD blood samples offered no supplemental diagnostic or disease activity information to that provided by standard laboratory measures of inflammation. S-nitrosothiols and 3-nitrotyrosine appeared not to be markers for active BD; thus the search for biochemical markers that will indicate the active period should be continued with larger studies.