RESUMO
BACKGROUND: Oxidative stress causes biochemical changes in lipids and proteins; these changes can induce damage to the vascular endothelium and create maternal complications that are characteristic of preeclampsia. In this study, we evaluated the oxidative profile of lipoproteins isolated from women with preeclampsia. METHODS: Thirty women diagnosed with preeclampsia and thirty women without preeclampsia were included in the study. Lipid-damage biomarkers, including conjugated dienes, lipohydroperoxides and malondialdehyde, were measured. The reduction of nitroblue tetrazolium, the formation of dityrosines, and the carbonylation of proteins were assessed as indicators of protein damage. The protective activity of HDL-c was evaluated by the paraoxonase-I activity present on the HDL-c particles. Serum lipid profiles were also quantified in both groups. Data were analysed using Student's t test and the Pearson correlation coefficient. RESULTS: Our results demonstrated in PE women evident oxidative changes in the lipids and proteins in HDL-c and LDL-c particles and the activity of the antioxidant enzyme PON-I decreased 59.9%. HDL-c exhibited self-defence, as demonstrated by the negative correlation between paraoxonase-I activity and the formation of lipohydroperoxides in HDL-c (r = -0.3755, p < 0.005). CONCLUSIONS: LDL-c and HDL-c isolated from women with preeclampsia show oxidative damage to lipids and proteins. We propose an oxidative profile based on the oxidation levels indicated by each of the markers used. We also found that paraoxonase-I is inactivated in the presence of lipohydroperoxides. Antioxidant support might be helpful to reduce oxidative stress in patients with preeclampsia. Further investigations are necessary to define the association between antioxidant activities and preeclampsia.
Assuntos
Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Pré-Eclâmpsia/sangue , Pré-Eclâmpsia/metabolismo , Adulto , Antioxidantes/metabolismo , Biomarcadores/sangue , Biomarcadores/metabolismo , Feminino , Humanos , Masculino , Malondialdeído/sangue , Malondialdeído/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Gravidez , Triglicerídeos/sangueRESUMO
OBJECTIVE: We studied the effect of pioglitazone on insulin levels, inflammation markers, high-density lipoprotein (HDL) composition and subclasses distribution, in young women with uncomplicated systemic lupus erythematosus (SLE). METHODS: This double-blind trial included 30 premenopausal women (30 ±8 years old) with SLE, who were randomized to pioglitazone (30 mg/day) or placebo treatment for 3 months. Plasma and HDL lipids were determined by colorimetric enzymatic assays, insulin by radioimmunometric assay, inflammation by immunonephelometry and HDL size and subclasses distribution by a native 4-30% polyacrylamide gradient gel electrophoresis. RESULTS: Compared with placebo, pioglitazone significantly increased HDL-cholesterol plasma levels (14.2%), reduced fasting insulin plasma levels (23.6%) and the homeostasis model assessment-insulin resistance (31.7%). C-reactive protein (70.9%) and serum amyloid A (34.9%) were also significantly reduced with the pioglitazone use, whereas the HDL particle size was increased (8.80 nm vs. 8.95 nm; p = 0.044) by changes in the distribution of HDL(2b), HDL(3b), and HDL(3c) subclasses. The change in HDL size correlated with a rise in free and cholesterol-ester content in the HDL particles. CONCLUSION: Pioglitazone significantly enhanced insulin sensitivity, reduced inflammation, and modified HDL characteristics, suggesting a potential beneficial effect of this drug in patients with SLE with a risk to develop cardiovascular disease. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov Protocol Registration System, with the number NCT01322308.
Assuntos
Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Hipoglicemiantes/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Tiazolidinedionas/uso terapêutico , Adulto , Método Duplo-Cego , Feminino , Humanos , Pioglitazona , Placebos/uso terapêutico , Estudos Prospectivos , Adulto JovemRESUMO
Little is known about qualitative abnormalities of high-density lipoproteins (HDL) in systemic lupus erythematosus (SLE). We studied distribution and composition of HDL subclasses in 30 premenopausal women with uncomplicated SLE, and 18 controls matched for age and sex. Plasma and HDL lipids were determined by colorimetric enzymatic assays, HDL size distribution by native gradient polyacrylamide gel electrophoresis (PAGE) and apolipoproteins in HDL by sodium dodecyl sulphate denaturing PAGE. Compared with controls, SLE patients had significantly lower proportions of HDL(2b) (-14.7%) and higher proportions of HDL(3b) (+8.8%) and HDL(3c) (+23.3%). Cholesteryl ester (-18%) and apolipoprotein AI (-9%) were lower, whereas triglycerides (+32%) and apolipoprotein E (+27%) were higher in SLE HDL (P < 0.05; for all). In the whole population, stepwise regression analysis showed that only insulin concentrations (R(2) = 0.327) and plasma total apo AI (R(2) = 0.114) accounted independently to the variance in HDL size. This study shows that HDL distribution and composition are abnormal in non-complicated SLE patients. These HDL abnormalities have been reported to be associated to impaired atheroprotective properties of HDL and prevalence of coronary heart disease. Therefore, they may contribute to the premature atherosclerosis observed in young women with SLE.