Atherogenic lipoproteins can cause endothelial dysfunction in the initial stage of atherogenesis. In our study we examined 134 patients with defined hyperlipoproteinemia (non-HDL cholesterol > 4.1 mmol/l or triglycerides > 2.5 mmol/l or taking any of lipid lowering drugs) – 94 men and 40 women. The subgroup of controls of comparable age contained 54 normolipidemic individuals – 30 men and 24 women. Patients with hyperlipoproteinemia revealed significantly lower ability of endothelium-dependent flow-mediated vasodilation (EDV) measured on brachial artery (4.13±3.07 vs. 5.41±3.82 %; p=0.032) and higher carotid intima media thickness than normolipidemic controls (0.68±0.22 vs. 0.58±0.15 mm; p=0.005). In regression analysis, EDV correlated significantly with plasma concentrations of oxLDL (p<0.05) HDL-cholesterol (p<0.05), Apo A1 (p<0.05), ATI (p<0.01) and non-HDL cholesterol (p<0.05). Patients with hyperlipoproteinemia showed higher plasma levels of oxLDL (65.77±9.54 vs. 56.49±7.80 U/l; p=0.015), malondialdehyde (0.89±0.09 vs. 0.73±0.08 µmol/l; p=0.010) and nitrites/nitrates (20.42±4.88 vs. 16.37±4.44 µmol/l; p=0.018) indicating possible higher long-term oxidative stress in these patients.
Oxidative stress plays an important role in the pathophysiology of preeclampsia. In a case-control study of 99 women with preeclampsia and 99 controls, we assessed maternal plasma oxidized low-density lipoprotein (oxidized LDL) in relation to preeclampsia risk. Logistic regression procedures were used to derive odds ratios (OR) and 95 % confidence intervals (CI). Plasma oxidized LDL was determined using enzyme immunoassay. Maternal plasma oxidized LDL was significantly positively correlated with lipids in both cases and controls. After adjusting for nulliparity, pre-pregnancy body mass index, physical inactivity, family history of chronic hypertension and plasma vitamin C concentrations, women who had elevated oxidized LDL concentrations (50 U/l) experienced a 2.9-fold increased risk of preeclampsia when compared with women having lower oxidized LDL concentrations (95 % CI 1.4-5.9). The risk of preeclampsia was markedly increased in women who had both elevated oxidized LDL and elevated triglyceride concentrations (OR=8.9, 95 % CI 3.1-26.2). Women with both elevated oxidized LDL and low vitamin C concentrations experienced a 9.8-fold increased risk of preeclampsia (95 % CI 3.0-32.2). Our results confirm the role of oxidative stress in the pathogenesis of preeclampsia. Prospective studies are needed to determine if elevated oxidized LDL concentrations can predict the occurrence of preeclampsia.