Oxidative Status In Patients Research Articles

Lipid peroxidation and antioxidant status in patients with rheumatoid arthritis.

The changes in the erythrocyte lipid peroxidation products (MDA), levels of glutathione (GSH), ascorbic acid and plasma vitamin E (non enzymatic antioxidant parameters) and activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GP(X)), catalase in erythrocytes and plasma glutathione - S - transferase (GST) activity were estimated in patients with rheumatoid arthritis. This work was undertaken to assess oxidative stress and anti oxidant status in patients with rheumatoid arthritis. It was observed that there was a significant increase in erythrocyte MDA levels, activities of SOD, GP(X), plasma GST and a significant decrease in erythrocyte GSH, ascorbic acid, plasma vitamin E levels and catalse activity in patients with rheumatoid arthritis when compared to controls. The results of our study suggests higher oxygen free radical production, evidenced by increased MDA and decreased GSH, ascorbic acid, vitamin E and Catalase activity, support to the oxidative stress in rheumatoid arthritis. The increased activities of antioxidant enzymes may be a compensatory regulation in response to increased oxidative stress.

PON1 activity and total oxidant status in patients with active pulmonary tuberculosis

Objectives: The aim of this study was to the investigate effect of tuberculosis infection on paraoxonase-1 (PON1) activity and oxidative status in patients with pulmonary tuberculosis (PTB). Design and methods: Twenty-five active PTB subjects and 33 healthy controls were included in the study. Serum PON1 activity, total oxidant status (TOS), lipid hydroperoxide (LOOH) and total free sulfydryl (-SH) groups were determined. Results: Serum basal/salt-stimulated paraoxonase activities, arylesterase activity and total -SH group levels were significantly lower in patients with PTB than controls ( p < 0.05, p < 0.05, p < 0.001 and p < 0.01 respectively), while TOS and LOOH levels were significantly higher ( p < 0.01 and p < 0.05, respectively). In PTB patients, TOS, LOOH and total -SH group levels were significantly correlated with paraoxonase ( r = − 0.371, p < 0.05; r = − 0.286, p < 0.05; r = 0.625 p < 0.01; respectively) and arylesterase ( r = − 0.437, p < 0.01; r = − 0.352, p < 0.05; r = 0.653, p < 0.01; respectively). Conclusions: Patients with active PTB are exposed to potent oxidative stress and they have decreased PON1 activity. These predisposal factors may, in part, play a role in the pathogenesis of atherosclerosis in PTB.

Serum paraoxonase 1 activity and oxidative markers of LDL in patients with cardiac syndrome X

Objective — Myocardial ischaemia in cardiac syndrome X (CSX) is believed to be due to microvascular dysfunction. Increased oxidative stress is one of the suspected mechanisms of microvascular dysfunction. The aim of this study was to evaluate the oxidative status in patients with CSX, by determining serum paraoxonase-1 (PON1) activity in addition to LDL-oxidation markers.Methods and results — This cross-sectional study consisted of patients with CSX (group I, n = 30), patients with coronary artery disease (group II, n = 31), and healthy controls (group III, n = 32). Lipid parameters, PON-1 activity, and LDL oxidation markers (conjugated-diene and thiobarbituric acid-reactive substance-TBARS) were measured. Endothelium-dependent vasodilatation was determined by brachial artery ultrasonography.There were no significant differences in serum LDL, apolipopro-tein-B, baseline LDL-diene, and LDL-TBARS levels between groups.There were no differences in both apolipoprotein-A1 and HDL levels between group I and group III. Apolipoprotein-A1 and HDL levels were significantly lower in group II than group I patients (P < 0.001). PON-1 activity was lowest in group II patients. Average PON-1 activity in group I was in between of group II and group III.The percent change of LDL-diene levels after stimulation was significantly higher in group II than in groups I and III (P = 0.005 and P = 0.02, respectively).The percent change of LDL-TBARS levels was lowest in group I (P = 0.03). There was a moderate correlation between endothelium-dependent vasodilatation and PON-1 activity in group I (r = 0.43, P = 0.04).Conclusions — Enhanced oxidative stress might be one of the causes of impaired endothelial functions resulting in myocardial ischaemia and chest pain in patients with CSX.The relatively preserved HDL and apolipoprotein-A1 levels in patients with CSX might be a protective mechanism against progression of coronary microvascular dysfunction to atherosclerotic coronary artery disease.

Effect of Atorvastatin on Type 2 Diabetic Dyslipidemia

Hyperlipidemia is commonly observed in patients with type 2 diabetes and is an independent risk factor for cardiovascular disease. The authors tested the effect of atorvastatin (10 mg/d) on 110 hyperlipidemic type 2 diabetes patients with low-density lipoprotein cholesterol (LDL-C) levels exceeding 130 mg/d. The primary efficacy end point was the percentage change in LDL-C and high-density lipoprotein cholesterol (HDL-C), and secondary efficacy included the percentage change in apolipoproteins at weeks 6, 12, and 24. The tertiary goal was percentage change in free radical scavenger enzymes and oxidative stress. LDL-C was reduced by 25%, 39.3%, and 49.2%. A similar trend was observed in total cholesterol, triglyceride, non-HDL-C, and apolipoprotein (apo) B-100. HDL-C was raised by 3.2%, 6%, and 8.2%. A similar trend was seen in apo A-1. Copper zinc-superoxide dismutase and glutathione were raised significantly (P < .001); however, changes in glutathione-S-transferase and glutathione peroxidase activities were nonsignificant. Malondialdehyde was decreased significantly (P < .001). Atorvastatin improves the lipoprotein profile and oxidative status in patients with type 2 diabetes.

Proxidant and antioxidant status in patients of type II Diabetes Mellitus with IHD

Patients with type II Diabetes Mellitus (NIDDM) are more prone to Ischaemic Heart Disease (IHD). Although, oxygen free radicals are known to contribute to the development of IHD, conflicting reports are available regarding the antioxidant status in patients of NIDDM complicated with IHD. This study was undertaken to investigate the oxidative status in patients of NIDDM and to assess their correlation with plasma glucose, glycosylated haemoglobin and duration of diabetes. The levels of malondialdehyde were significantly increased where as levels of superoxide dismutase, Glutathione peroxidase and vitamin C were significantly decreased in diabetics without complications and non-diabetics with IHD when compared with the controls. The levels of malondialdehyde and Glutathione peroxidase were significantly increased where as levels of superoxide dismutase and vitamin C were significantly decreased in diabetics with IHD when compared with diabetics without complications and non-diabetics with IHD. The implications of the results are discussed.

Evidence for oxidative stress at elevated plasma thiol levels in chronic exposure to carbon disulfide (CS 2) and coronary heart disease

Objectives Oxidative stress in plasma may be promoted by plasma thiols such as homocysteine. However, other thiols such as glutathione may also exert antioxidant effects in vitro and in vivo. To further investigate whether plasma thiols act as prooxidants or antioxidants, we compared plasma oxidative status in patients with coronary heart disease (CHD) and in subjects occupationally exposed to carbon disulfide (CS 2). Methods Fifty-five subjects chronically exposed to CS 2, 53 CHD patients, and 52 healthy controls were examined. To assess plasma oxidative status, concentrations of thiobarbituric reactive substances (TBARS) and total antioxidative capacity (TAC), as well as ferritin and ceruloplasmin were determined. Antioxidative reserve was assessed by the determination of vitamine E, uric acid, superoxide dismutase, catalase, and glutathion peroxidase. In addition, protein and non-protein plasma thiol levels were measured. Results Patients in both groups had increased levels of plasma thiols as compared to controls: CS 2-exposed subjects presented with increased levels of thiols associated with plasma proteins, whereas CHD patients presented with elevated total homocysteine and cysteine levels. TBARS were significantly increased and TAC was significantly decreased both in CS 2-exposed subjects and in CHD patients. In addition decreased activity of glutathione peroxidase, an antioxidative enzyme inhibited by thiol-containing compounds, was noted in both groups. Conclusion These results demonstrate that regardless of their metabolic origin increased thiols are associated with increased oxidative stress in plasma.

Erythrocyte deformability, plasma viscosity and oxidative status in patients with severe obstructive sleep apnea syndrome

Background and purposeIn patients with severe obstructive sleep apnea syndrome (OSAS), diurnal changes of plasma viscosity and erythrocyte deformability were measured to elucidate the possible mechanism of cardiovascular diseases in OSAS patients. Patients and methodsPlasma viscosity and erythrocyte deformability was determined in 11 OSAS patients and 11 healthy subjects matched by sex and age. Plasma viscosity was measured by a cone-plate viscometer, and erythrocyte deformability was determined by filtration technique. Whole blood counts were performed and oxidative status of the patients' plasma and erythrocytes were evaluated. ResultsOSAS patients had higher plasma viscosity than controls, both in the morning (1.74±0.3 vs. 1.36±0.2mPas, P<0.002) and evening (1.55±0.2 vs. 1.27±0.1mPas, P<0.002), and morning plasma viscosity was significantly higher than the evening level (P<0.05). Morning plasma viscosity of patients was inversely correlated with their mean nocturnal SaO2. Morning plasma malonyldialdehyde level was significantly higher in the patients than in the controls (69.7±30.5 vs. 45.5±11.0nmol/l, P<0.005). Erythrocyte deformability of the patients was slightly lower. ConclusionsWe have observed that plasma viscosity is high both in the morning and in the evening in severe OSAS patients. This elevation may predispose OSAS patients to myocardial infarction and stroke by increasing blood viscosity. Low nocturnal mean SaO2 may be responsible for the high plasma viscosity in these patients.

Oxidative status in patients submitted to conization and radiation treatments for uterine cervix neoplasia

Background Cervical cancer is a major cause of morbidity among women. We investigated the treatment effect on oxidative status from patients submitted to radiotherapy or conization surgery to high-grade SIL (squamous intraepithelial lesion) treatment, and oxidative profile from patients newly diagnosed for uterine cervix cancer, without treatment. Methods We determined the catalase activity in blood, reduced glutathione (GSH) in plasma, TBARS and protein carbonyl content from serum samples of the patients. Results The catalase activity, GSH levels, TBARS and protein carbonyl content had no statistical differences related to the controls, neither when the 2 treatments were compared, possibly because the antioxidant defense may be acting in the first period of the neoplasic transformation, and maybe indicating a possible arrest of the tumor cells caused by the efficiency of the treatments. In the non-treated patients, TBARS and protein carbonyl contents, GSH levels and catalase activity were shown to be increased comparing with the treated patients and compared with the controls indicating an tumor effect on oxidative profile, and the antioxidant activity been increased in the beginning of the tumor development. Conclusions We suggest that the treatments were efficient in arrest of the tumor.

Increased oxidative stress associated with the severity of the liver disease in various forms of hepatitis B virus infection

BackgroundOxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection.MethodsSeventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants.ResultsTotal antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p < 0.001, both) and chronic hepatitis B subjects (p < 0.001, both) than inactive HbsAg carriers and controls. Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively).ConclusionOxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection.

Oxidative Status in Patients with Alcohol Dependence: A Clinical Study in Taiwan

The aim of this study is to examine the relationship between alcohol dependence and oxidative status. The biochemical parameters and antioxidants status were measured among 28 patients with alcohol dependence. Nineteen healthy persons without drinking problem were recruited as the control subjects. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (γ-GT), and levels of cholesterol, triglyceride (TG), and uric acid were significantly increased in the specimen of patients compared with control. Serum malondialdehyde (MDA) levels of the patients were found to be significantly increased compared with controls and decreased after abstinence. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were, respectively, 86% and 37% lower in alcoholic patients. After 14 d of abstinence, SOD activity was significantly reduced by 85%, CAT by 52%, and GPX by 54%, whereas no change was found in activity of glutathione reductase (GR). The duration of alcohol dependence is significantly correlated with the levels of MDA. In addition, the activity of CAT was significantly correlated with MDA levels. The results of this study suggest that oxidative stress occurred during alcohol dependence and subsequently affected the antioxidants mechanisms.

Increased Oxidative Damage with Altered Antioxidative Status in Type 2 Diabetic Patients Harboring the 16189 T to C Variant of Mitochondrial DNA

A transition of T to C at nucleotide position 16189 in mitochondrial DNA (mtDNA) has attracted biomedical researchers for its probable correlation with the development of diabetes mellitus in adult life. In diabetes, persistent hyperglycemia may cause high production of free radicals. Reactive oxygen species are thought to play a role in a variety of physiologic and pathophysiologic processes in which increased oxidative stress may play an important role in disease mechanisms. The aim of the present study was to clarify the degree of oxidative damage and plasma antioxidant status in diabetic patients and to see the potential influence of the 16189 variant of mtDNA on the oxidative status in these patients. An indicative parameter of lipid peroxidation, malondialdehyde (MDA), and total free thiols were measured from plasma samples of 165 type 2 diabetic patients with or without this variant and 168 normal subjects. Here we report an increase in the plasma levels of MDA and total thiols in type 2 diabetic patients compared with control subjects. The levels of plasma thiols in diabetic patients with the 16189 variant of mtDNA were not different from those in controls. These results suggest an increase in the oxidative damage and a compensatory higher antioxidative status in patients with type 2 diabetes. Harboring the 16189 mtDNA variant may impair the ability of a cell to respond properly to oxidative stress and oxidative damage.

Diabetes mellitus worsens antioxidant status in patients with chronic pancreatitis1–3

Patients with chronic pancreatitis (CP) are at high risk of antioxidant deficiencies. Furthermore, this disease can lead to diabetes mellitus (DM) that could exacerbate the severity of oxidative stress. Oxidative stress and the resulting LDL oxidation are a major cause of atherosclerosis. The objective of the study was to ascertain whether diabetes significantly modifies oxidative status in patients with CP. CP patients with or without DM were compared with type 1 DM patients and healthy control subjects. Two-way factorial analyses showed that a decrease in the plasma concentrations of vitamin A, vitamin E, and carotenoids accompanied both CP and DM, and CP was also associated with lower plasma concentrations of selenium and zinc, lower catalase activity, and higher plasma concentrations of copper. The lag phase of LDL oxidation was lower in CP patients with or without DM than in the control subjects, whereas there was no significant difference between type 1 DM patients and control subjects. Multivariate analysis showed that LDL vitamin E (R2 = 0.24, P < 0.0001) and fasting plasma glucose (R2 = 0.32, P < 0.0001) concentrations were the main determinants of the lag phase of LDL oxidation. Antioxidant status is altered in CP patients, particularly in those who also have DM. In these patients, a vitamin E deficiency and an elevated plasma glucose concentration were associated with significantly higher LDL oxidizability.

Plasma Nitric Oxide Status in Patients with Drug-Induced Acute Renal Failure

Plasma Nitric Oxide Status in Patients with Drug-Induced Acute Renal Failure

Effect of High Intakes of Fruit and Vegetables on Redox Status in Type 2 Onset Diabetes: A Pilot Study

Evidence has accumulated indicating that oxidative stress may play a key role in the etiology of diabetic complications and the protective effects of antioxidant nutrients are a topic of intense research. The purpose of this study was both to obtain preliminary data on the effect of a diet high in fruit and vegetables on metabolic control and the oxidative status of patients with type 2 onset diabetes, and to identify the most useful biochemical parameters for future research. At the beginning of the study all subjects were asked to follow their usual diet and keep a seven-day food diary. Diabetic patients then received a dietary treatment designed to ensure a daily intake of 700-1000 g of fruit and vegetables; no dietary advice was given to controls. Dietary antioxidants, redox status markers, and parameters of metabolic control were measured in plasma and erythrocytes before and after the diet. Before following the diet, diabetic patients had lower levels of ascorbic acid, beta-carotene, and alpha-tocopherol/cholesterol ratio than controls. After the diet these parameters increased and there was also a reduction in total antioxidant capacity, uric acid, and malondialdehyde and a rise in reduced glutathione accompanied by a reduction in body mass index and cholesterol. In conclusion, a high consumption of fruit and vegetables by diabetic patients not receiving pharmacological treatment, seems to produce an improvement in some redox status parameters.

Protein oxidation status in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease with unknown aetiology. Since various functions of neutrophils are increased in AS, neutrophil activation-mediated oxidative stress may have an important role in the pathogenesis of AS. Therefore, the importance of neutrophil activation as the main source of oxidative stress was investigated in patients with AS. Forty-one patients with AS, divided into active and inactive groups according to their CRP and ESR, and 30 healthy volunteers were entered into the study. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the visual analogue scale (VAS) were also used in all patients before the study. In addition, the patients were evaluated according to spinal involvement and peripheral involvement. Plasma myeloperoxidase (MPO) activity, representing neutrophil activation, and oxidative stress biomarkers, such as advanced oxidation protein products (AOPP) and thiol levels, were measured. There were significant increases in plasma MPO activity and AOPP but decreases in thiol levels in the total AS patient group and in the subgroups, compared with controls. All parameters, except thiol, were higher in active and peripheral involvement groups than in the inactive and spinal patients, respectively; but the highest levels were observed in the peripheral subgroup. In addition, AOPP was found to be positively correlated with ESR, CRP and BASDAI in the total patient group and with white blood cell and neutrophil count in the peripheral involvement subgroup. BASDAI was positively correlated with VAS, ESR and CRP; but MPO was negatively correlated with thiol/albumin ratio, both in total and active AS patients. Negative correlations were also observed between albumin and ESR, and between CRP and neutrophil counts in the peripheral subgroup. This is the first study suggesting neutrophil-MPO-hypochlorous acid-mediated AOPP formation in AS. Therefore, active neutrophils and chlorinated oxidants of neutrophil origin may be considered to be important factors in the pathogenesis of AS which are related to oxidative stress, notably protein oxidation.

Oxidative Status in Chronic Hepatitis C: The Influence of Antiviral Therapy and Prognostic Value of Serum Hydroperoxide Assay

The effect of α-interferon (α-IFN) and ribavirin (RBV) treatment on oxidative status in chronic hepatitis C (CHC) is unknown.Aim: To study the time course of oxidative status in patients with CHC during α-IFN and RBV administration, and to evaluate the role of oxidative status in order to predict the therapeutic response.Patients and methods: Fifty one patients with CHC were studied. All received a combination of α-IFN and RBV for 6 or 12 months in relation to the type of response. The hydroperoxides concentration in serum test samples by D-ROM test was measured in all of the patients before therapy. In 27 patients, hydroperoxides were also measured during the treatment and during the 12 subsequent months.Results: Cross-sectional analysis demonstrates that patients with a successive long-term response had a lower basal serum hydroperoxide concentration than non-responders (280±40.8 vs 337±83 CARR Units, p<0.05). This resulted to be an independent factor predictive of long-term response in the multi-varied analysis. Longitudinal observation on 27 patients showed that the mean hydroperoxide concentration decreased significantly during treatment (T0 329±79.2 vs T12 272±34.5 CARR Units) and that the decrease in the mean values was mainly due to variations in the relapsers group.Conclusions: Normal basal hydroperoxide concentration helps to predict long-term response to combination therapy. The D-ROM test may be used for screening patients before treatment.

Alterations in Plasma Essential Trace Elements Selenium, Manganese, Zinc, Copper, and Iron Concentrations and the Possible Role of these Elements on Oxidative Status in Patients with Childhood Asthma

The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations, malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status. Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r= 0.485, p<0.021), and a negative correlation between TAC and MDA values (r= -0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood asthma may be responsible for the oxidant/antioxidant imbalance.

Effect of Dialysis on Plasma Total Antioxidant Capacity and Lipid Peroxidation Products in Patients with End-Stage Renal Failure

Dialysis is associated with an impairment of antioxidant defense and an overproduction of oxidative stress markers. This study focuses on the comparison of plasma total antioxidant capacity (TAC) and lipid peroxidation products in patients on hemodialysis (HD) before and after treatment and in peritoneal dialysis (PD) patients. Plasma TAC, malonaldehyde (MDA), and 4-hydroxyalkenal concentrations were measured in 31 HD patients, in 24 PD patients, and in 17 normal controls (NC). It was found that before HD, TAC and MDA levels were higher than those in the NC (p < 0.001). After HD, these levels decreased significantly but were higher than in NC and lower than in PD patients (p < 0.001). The levels of 4-hydroxyalkenals were elevated in patients as compared with NC, but did not differ between HD and PD patients. The MDA concentrations correlated positively with the TAC in the patients. It is concluded that the oxidative status of patients on HD is similar to that of patients on PD and that the susceptibility to oxidative stress is strongly related to the levels of MDA produced in plasma.

Plasma lipid oxidation and susceptibility of low-density lipoproteins to oxidation in male patients with stable coronary artery disease

Objectives: Oxidative modifications of low-density lipoproteins (LDL) are considered to be important in the pathogenesis of atherosclerosis. However, the data on the association between LDL oxidation and severity of clinical manifestations of coronary artery disease (CAD) are contradictory. Previous reports were concerned mostly with unstable angina patients. The present study was undertaken to evaluate plasma lipid oxidation status in patients with stable CAD. Design and Methods: 37 male patients with angiographically confirmed CAD (asymptomatic or suffering from stable angina pectoris) and 32 control subjects were used in the study. Plasma levels of vitamin E and products of lipid peroxidation, as well as parameters of the test for oxidizability of LDL in vitro were measured. Results: We did not find differences between 2 groups of individuals regarding the levels of products of lipid peroxidation, vitamin E levels, lag time, maximal rate of oxidation, and total amount of conjugated dienes in the test for oxidizability of LDL. Conclusion: The results of our study challenge, but do not disprove, the oxidative hypothesis of atherosclerosis. Real atherosclerotic modifications of plasma LDL occur apparently in the vascular wall after trapping of LDL by the interstitial matrix. The rise in oxidative parameters in unstable angina reported in the literature may not be the cause of the disease but, rather, the consequence of the multiple brief episodes of ischemia-reperfusion.

Pregnancy-Induced Hypertension: Evidence for Altered Functional Features of Platelets

Objective: Among the pathogenetic factors of pregnancy-induced hypertension (PIH), oxidative damage seems to play a pivotal role. The aim of this study is to investigate if the oxidative status in patients with PIH could induce the altered platelet reactivity responsible for the abnormal uteroplacental microcirculation.Methods: Twenty pregnant women with PIH were admitted to our study. The presence of a mild hypertensive disorder was defined on the basis of blood pressure, proteinuria, and serum uric acid levels. Fifteen normotensive pregnant women and 15 nonpregnant women represented the control groups. The serum lipemic profile, including apoproteins, was measured to confirm that all subjects were normolipemic and, consequently, to avoid the influence of these parameters on platelet reactivity. Malondialdehyde (MDA), as an index of lipid peroxidation and cyclooxygenase pathway activation, was determined in plasma and in unstimulated and thrombin-stimulated platelets. Measurements of platelet membrane mi...