Low-density lipoprotein (LDL)-induced monocyte-endothelial cell adhesion, soluble cell adhesion molecules, and autoantibodies to oxidized-LDL in chronic renal failure patients on dialysis therapy

PPARγ in Atherosclerotic Endothelial Dysfunction: Regulatory Compounds and PTMs

The formation of atherosclerotic plaques is one of the main sources of cardiovascular disease. In addition to known risk factors such as dyslipidemia, diabetes, obesity, and hypertension, endothelial dysfunction has been shown to play a key role in the formation and progression of atherosclerosis. Peroxisome proliferator-activated receptor-gamma (PPARγ), a transcription factor belonging to the steroid superfamily, is expressed in the aorta and plays a critical role in protecting endothelial function. It thereby serves as a target for treating both diabetes and atherosclerosis. Although many studies have examined endothelial cell disorders in atherosclerosis, the role of PPARγ in endothelial dysfunction is still not well understood. In this review, we summarize the possible mechanisms of action behind PPARγ regulatory compounds and post-translational modifications (PTMs) of PPARγ in the control of endothelial function. We also explore the potential use of endothelial PPARγ-targeted agents in the prevention and treatment of atherosclerosis.

Novel oxidized LDL-based clinical markers in peritoneal dialysis patients for atherosclerosis risk assessment

Maintenance peritoneal dialysis (PD) is commonly associated with cardiovascular diseases (CVDs), whose risk is assessed via LDL-C. Nonetheless, oxidized LDL (oxLDL), as being a key component of atherosclerotic lesions, could be also associated with atherosclerosis and related CVDs. However, its predictive value for CVDs risk assessment is subject of research studies due to the lack of specific methods to measure oxLDL status from its individual lipid/protein components. In the present study, six novel oxLDL markers, representative of certain oxidative modifications on the LDL protein and lipid components, are measured in atherosclerosis-prone PD patients (39) versus those in chronic kidney disease patients (61) under hemodialysis (HD) and healthy controls (40). LDL from serum of PD, HD and control subjects were isolated and fractionated into cholesteryl esters, triglycerides, free cholesterol, phospholipids and apolipoprotein B100 (apoB100). Subsequently the oxLDL markers cholesteryl ester hydroperoxides (-OOH), triglyceride-OOH, free cholesterol-OOH, phospholipid-OOH, apoB100 malondialdehyde and apoB100 dityrosines were measured. LDL carotenoid levels and LDL particle serum concentration were also measured. The levels of all oxLDL lipid-OOH markers were significantly elevated in PD patients versus control, while the levels of cholesteryl ester-/triglyceride-/free cholesterol-OOH were significantly elevated in PD versus HD patients, regardless of patients' underlying medical conditions, sex, age, PD type, clinical biochemical markers and medication. It should be noted that all fractionated lipid-OOH levels were inversely correlated with LDL-P concentration, while LDL-P concentration was not correlated with LDL-C in PD patients. Moreover, LDL carotenoids were significantly lower in PD patients versus control. The increased levels of oxLDL status specific markers in both PD and HD patients (compared to control), support a potential prognostic value of oxLDL regarding CVD risk assessment in both patient groups. Lastly, the study introduces the oxLDL peroxidation markers free cholesterol-OOH and cholesteryl ester-OOH as complementary to LDL-P number, and as possible alternatives to LDL-C.

Head-to-Head Comparison of Oxidative Stress Biomarkers for All-Cause Mortality in Hemodialysis Patients

Oxidative stress (OS) presents even in the early chronic kidney disease (CKD) stage and is exacerbated in patients with end-stage renal disease (ESRD) undergoing maintenance hemodialysis (MHD). There is still a debate over the association between oxidative stress and mortality. Our study aims to compare head-to-head the prognostic value of different oxidative markers for all-cause mortality in hemodialysis (HD) patients. We thus enrolled 347 patients on HD in this prospective study. Four OS biomarkers were measured (carbonyl proteins, myeloperoxidase (MPO), advanced oxidation protein products (AOPPs), and oxidized low-density lipoprotein (ox-LDL)). During the 60-month follow-up period, 9 patients have been lost to follow-up and 168 (48.4%) patients died. Concerning the oxidative stress (ox-stress) byproducts, carbonyl proteins were lower in survivors (105.40 ng/mL (IQR 81.30−147.85) versus 129.65 ng/mL (IQR 93.20−180.33); p < 0.001), with similar results for male patients (103.70 ng/mL (IQR 76.90−153.33) versus 134.55 ng/mL (IQR 93.95−178.68); p = 0.0014). However, there are no significant differences in MPO, AOPP, and ox-LDL between the two groups. Kaplan−Meier survival analysis indicated that patients in the higher carbonyl proteins concentration (>117.85 ng/mL group) had a significantly lower survival rate (log-rank test, p < 0.001). Univariate Cox regression analysis showed a positive correlation between carbonyl proteins and all-cause mortality in the higher and lower halves. Even after adjustment for conventional risk factors, it remained a statistically significant predictor of an increased risk of death in MHD. Univariate Cox regression analysis of MPO showed that continuous MPO and Log MPO were significantly associated with all-cause mortality, except for binary MPO (divided according to the median of MPO). Multivariate Cox analysis for MPO showed that the mortality prediction remains significant after adjusting for multiple factors. In conclusion, not all ox-stress biomarkers predict all-cause mortality in HD patients to a similar extent. In the present study, carbonyl proteins and MPO are independent predictors of all-cause mortality in HD patients, whereas AOPPs and oxLDL are clearly not associated with all-cause mortality in HD patients.

Lipotoxicity and Diabetic Nephropathy: Novel Mechanistic Insights and Therapeutic Opportunities

Lipotoxicity is characterized by the ectopic accumulation of lipids in organs different from adipose tissue. Lipotoxicity is mainly associated with dysfunctional signaling and insulin resistance response in non-adipose tissue such as myocardium, pancreas, skeletal muscle, liver, and kidney. Serum lipid abnormalities and renal ectopic lipid accumulation have been associated with the development of kidney diseases, in particular diabetic nephropathy. Chronic hyperinsulinemia, often seen in type 2 diabetes, plays a crucial role in blood and liver lipid metabolism abnormalities, thus resulting in increased non-esterified fatty acids (NEFA). Excessive lipid accumulation alters cellular homeostasis and activates lipogenic and glycogenic cell-signaling pathways. Recent evidences indicate that both quantity and quality of lipids are involved in renal damage associated to lipotoxicity by activating inflammation, oxidative stress, mitochondrial dysfunction, and cell-death. The pathological effects of lipotoxicity have been observed in renal cells, thus promoting podocyte injury, tubular damage, mesangial proliferation, endothelial activation, and formation of macrophage-derived foam cells. Therefore, this review examines the recent preclinical and clinical research about the potentially harmful effects of lipids in the kidney, metabolic markers associated with these mechanisms, major signaling pathways affected, the causes of excessive lipid accumulation, and the types of lipids involved, as well as offers a comprehensive update of therapeutic strategies targeting lipotoxicity.

Variable Effects Of LDL Subclasses Of Cholesterol On Endothelial Nitric Oxide/Peroxynitrite Balance - The Risks And Clinical Implications For Cardiovascular Disease

Background

Elevated levels of low density lipoprotein (LDL), “bad cholesterol”, is not an accurate indicator of coronary disease. About 75% of patients with heart attacks have cholesterol levels that do not indicate a high risk for a cardiovascular event. LDL is comprised of three subclasses, with particles of different size and density. We used nanomedical systems to elucidate the noxious effects of LDL subclasses on endothelium.

Experimental

Nanosensors were employed to measure the concentrations of nitric oxide (NO) and peroxynitrite (ONOO⁻) stimulated by LDL subclasses in HUVECs. N-LDL and ox-LDL (subclass A: 1.016–1.019 g/mL, subclass I: 1.024–1.029 g/mL, and subclass B: 1.034–1.053 g/mL) stimulated NO and ONOO⁻ release. The concentrations ratio of (NO)/(ONOO⁻) was used to evaluate the noxious effects of the subclasses on endothelium.

Results

In HUVECs, the (NO)/(ONOO⁻) ratio for normal endothelium is about 5, but shifts to 2.7±0.4, 0.5±0.1, and 0.9±0.1 for subclasses A, B, and I, respectively. Ratios below 1.0 indicate an imbalance between NO and ONOO⁻, affecting endothelial function. LDL of 50% B and 50% I produced the most severe imbalance (0.45±0.04), whereas LDL of 60% A, 20% B, and 20% I had the most favorable balance of 5.66±0.69. Subclass B significantly elevated the adhesion of molecules and monocytes. The noxious effect was significantly higher for ox-LDL than n-LDL.

Conclusion

Subclass B of “bad cholesterol” is the most damaging to endothelial function and can contribute to the development of atherosclerosis. Contrary to the current national guidelines, this study suggests that it’s not the total LDL, rather it is the concentration of subclass B in relation to subclasses A and/or I, that should be used for diagnosis of atherosclerosis and the risk of heart attack. By utilizing specific pharmacological therapy to address the concentration of subclass B, there is a potential to significantly reduce the risk of heart attack and atherosclerosis.

Antioxidant Supplementation in Renal Replacement Therapy Patients: Is There Evidence?

The disruption of balance between production of reactive oxygen species and antioxidant systems in favor of the oxidants is termed oxidative stress (OS). To counteract the damaging effects of prooxidant free radicals, all aerobic organisms have antioxidant defense mechanisms that are aimed at neutralizing the circulating oxidants and repair the resulting injuries. Antioxidants are either endogenous (the natural defense mechanisms produced by the human body) or exogenous, found in supplements and foods. OS is present at the early stages of chronic kidney disease, augments progressively with renal function deterioration, and is further exacerbated by renal replacement therapy. End-stage renal disease patients, on hemodialysis (HD) or peritoneal dialysis (PD), suffer from accelerated OS, which has been associated with increased risk for mortality and cardiovascular disease. During HD sessions, the bioincompatibility of dialyzers and dialysate trigger activation of white blood cells and formation of free radicals, while a significant loss of antioxidants is also present. In PD, the bioincompatibility of solutions, including high osmolality, elevated lactate levels, low pH, and accumulation of advanced glycation end-products trigger formation of prooxidants, while there is significant loss of vitamins in the ultrafiltrate. A number of exogenous antioxidants have been suggested to ameliorate OS in dialysis patients. Vitamins B, C, D, and E, coenzyme Q10, L-carnitine, a-lipoic acid, curcumin, green tea, flavonoids, polyphenols, omega-3 polyunsaturated fatty acids, statins, trace elements, and N-acetylcysteine have been studied as exogenous antioxidant supplements in both PD and HD patients.

Oxidative stress in hemodialysis: Causative mechanisms, clinical implications, and possible therapeutic interventions

Oxidative stress (OS) is the result of prooxidant molecules overwhelming the antioxidant defense mechanisms. Hemodialysis (HD) constitutes a state of elevated inflammation and OS, due to loss of antioxidants during dialysis and activation of white blood cells triggering production of reactive oxygen species. Dialysis vintage, dialysis methods, and type and condition of vascular access, biocompatibility of dialyzer membrane and dialysate, iron administration, and anemia all can play a role in aggravating OS, which in turn has been associated with increased morbidity and mortality. Oral or intravenous administration of antioxidants may detoxify the oxidative molecules and at least in part repair OS-mediated tissue damage. Lifestyle interventions and optimization of a highly biocompatible HD procedure might ameliorate OS development in dialysis.

Oxidative Stress in Patients Undergoing Peritoneal Dialysis: A Current Review of the Literature

Peritoneal dialysis (PD) patients manifest excessive oxidative stress (OS) compared to the general population and predialysis chronic kidney disease patients, mainly due to the composition of the PD solution (high-glucose content, low pH, elevated osmolality, increased lactate concentration and glucose degradation products). However, PD could be considered a more biocompatible form of dialysis compared to hemodialysis (HD), since several studies showed that the latter results in an excess accumulation of oxidative products and loss of antioxidants. OS in PD is tightly linked with chronic inflammation, atherogenesis, peritoneal fibrosis, and loss of residual renal function. Although exogenous supplementation of antioxidants, such as vitamins E and C, N-acetylcysteine, and carotenoids, in some cases showed potential beneficial effects in PD patients, relevant recommendations have not been yet adopted in everyday clinical practice.

Oxidative Stress in Hemodialysis Patients: A Review of the Literature

Hemodialysis (HD) patients are at high risk for all-cause mortality and cardiovascular events. In addition to traditional risk factors, excessive oxidative stress (OS) and chronic inflammation emerge as novel and major contributors to accelerated atherosclerosis and elevated mortality. OS is defined as the imbalance between antioxidant defense mechanisms and oxidant products, the latter overwhelming the former. OS appears in early stages of chronic kidney disease (CKD), advances along with worsening of renal failure, and is further exacerbated by the HD process per se. HD patients manifest excessive OS status due to retention of a plethora of toxins, subsidized under uremia, nutrition lacking antioxidants and turn-over of antioxidants, loss of antioxidants during renal replacement therapy, and leukocyte activation that leads to accumulation of oxidative products. Duration of dialysis therapy, iron infusion, anemia, presence of central venous catheter, and bioincompatible dialyzers are several factors triggering the development of OS. Antioxidant supplementation may take an overall protective role, even at early stages of CKD, to halt the deterioration of kidney function and antagonize systemic inflammation. Unfortunately, clinical studies have not yielded unequivocal positive outcomes when antioxidants have been administered to hemodialysis patients, likely due to their heterogeneous clinical conditions and underlying risk profile.

Anti-inflammatory and Antioxidant Effects of Sesame Oil on Atherosclerosis: A Descriptive Literature Review

Sesame oil (SO) is a supplement that has been known to have anti-inflammatory and antioxidant properties, which makes it effective for reducing atherosclerosis and the risk of cardiovascular disease. Due to the side effects of statins, the current recommended treatment for atherosclerosis and cardiovascular diseases, the idea of using dietary and nutritional supplementation has been explored. The benefits of a dietary health regime have piqued curiosity because many different cultures have reaped health benefits through the ingredients in their cooking with negligible side effects. The purpose of this literary review is to provide a broad overview of the potential benefits and risks of SO on the development of atherosclerosis and its direction toward human clinical use. Current in vivo and in vitro research has shed light on the effects of SO and its research has shown that SO can decrease low-density lipoprotein (LDL) levels while maintaining high-density lipoprotein (HDL) levels. Current limitations in recent studies include no standardized doses of SO given to subjects and unknown specific mechanisms of the different components of SO. Future studies should explore possible synergistic and adverse effects of SO when combined with current recommended pharmaceutical therapies and other adjunct treatments.

Apple Polyphenols Decrease Atherosclerosis and Hepatic Steatosis in ApoE-/- Mice through the ROS/MAPK/NF-κB Pathway

In this study, we examined the effects of apple polyphenols (APs) on hyperlipidemia, atherosclerosis, hepatic steatosis and endothelial function and investigated the potential mechanisms. ApoE^−/− mice were fed a western-type diet and orally treated with APs (100 mg/kg) or atorvastatin (10 mg/kg) for 12 weeks. Hyperlipidemia and atherosclerosis in the aortic sinuses and, and hepatic lipidosis were measured. The treatment with APs or atorvastatin induced a remarkable reduction in the atherosclerotic lesions and hepatic steatosis and decreased the levels of low-density lipoprotein, triglyceride, CCL-2 and VCAM-1 levels in the plasma. Conversely, the APs significantly increased the plasma levels of high-density lipoprotein (HDL) cholesterol and markedly up-regulated the glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) levels in liver tissues. Moreover, the APs treatment modulated lipid metabolism by up-regulating the transcription of associated hepatic genes including PPARα, while down-regulating the transcription of SCAP and its downstream genes associated with lipid synthesis in the liver. Histological assessment showed that the APs treatment also reduced the macrophage infiltration in the aortic root plaque and the inflammatory cells infiltrations to the liver tissues. Moreover, we confirmed that the APs treatment greatly reduced the ox-LDL-induced endothelial dysfunction and monocyte adhesion to rat aortic endothelial cells (RAECs). Mechanistically, the APs treatment suppressed the ROS/MAPK/NF-κB signaling pathway, and consequently, reduced CCL-2, ICAM-1 and VCAM-1 expression. Our results suggest that the APs are a beneficial nutritional supplement for the attenuation of atherosclerosis.

Autoantibodies to posttranslational modifications in rheumatoid arthritis

Autoantibodies have been associated with human pathologies for a long time, particularly with autoimmune diseases (AIDs). Rheumatoid factor (RF) is known since the late 1930s to be associated with rheumatoid arthritis (RA). The discovery of anticitrullinated protein antibodies in the last century has changed this and other posttranslational modifications (PTM) relevant to RA have since been described. Such PTM introduce neoepitopes in proteins that can generate novel autoantibody specificities. The recent recognition of these novel specificities in RA provides a unique opportunity to understand human B-cell development in vivo. In this paper, we will review the three of the main classes of PTMs already associated with RA: citrullination, carbamylation, and oxidation. With the advancement of research methodologies it should be expected that other autoantibodies against PTM proteins could be discovered in patients with autoimmune diseases. Many of such autoantibodies may provide significant biomarker potential.

Aberrant function and differentiation of monocytes in end stage renal disease

Patients with end stage renal disease (ESRD) suffer from many disturbances of the immune system. These immunopathologies are related to the higher failure of vaccination, and increased prevalence of infections and neoplasms. In the presented article, we review the current data regarding the role of monocytes in immune dysfunctions which are observed in terminal renal failure. As monocytes play a pivotal role in regulating the function of the immune system, their dysfunction can have a profound effect on the immune system and may lead to accelerated arteriosclerosis and deteriorating overall health conditions. More specifically, we suggest that peripheral blood monocytes in patients with ESRD are chronically activated, and their functional and phenotypical features resemble those of inflammatory macrophages. This state of chronic inflammation is unfavorable for dendritic cells and consequently, the prevalence of dendritic cells is reduced. As these effects are consistent across different modes of dialysis, they are probably mediated by the uremia itself.

18FDG PET-CT imaging detects arterial inflammation and early atherosclerosis in HIV-infected adults with cardiovascular disease risk factors

BACKGROUND

Persistent vascular inflammation has been implicated as an important cause for a higher prevalence of cardiovascular disease (CVD) in HIV-infected adults. In several populations at high risk for CVD, vascular 18Fluorodeoxyglucose (18FDG) uptake quantified using 3D-positron emission-computed tomography (PET-CT) has been used as a molecular level biomarker for the presence of metabolically active proinflammatory macrophages in rupture-prone early atherosclerotic plaques. We hypothesized that 18FDG PET-CT imaging would detect arterial inflammation and early atherosclerosis in HIV-infected adults with modest CVD risk.

METHODS

We studied 9 HIV-infected participants with fully suppressed HIV viremia on antiretroviral therapy (8 men, median age 52 yrs, median BMI 29 kg/m2, median CD4 count 655 cells/μL, 33% current smokers) and 5 HIV-negative participants (4 men, median age 44 yrs, median BMI 25 kg/m2, no current smokers). Mean Framingham Risk Scores were higher for HIV-infected persons (9% vs. 2%, p < 0.01). 18FDG (370 MBq) was administered intravenously. 3D-PET-CT images were obtained 3.5 hrs later. 18FDG uptake into both carotid arteries and the aorta was compared between the two groups.

RESULTS

Right and left carotid 18FDG uptake was greater (P < 0.03) in the HIV group (1.77 ±0.26, 1.33 ±0.09 target to background ratio (TBR)) than the control group (1.05 ± 0.10, 1.03 ± 0.05 TBR). 18FDG uptake in the aorta was greater in HIV (1.50 ±0.16 TBR) vs control group (1.24 ± 0.05 TBR), but did not reach statistical significance (P = 0.18).

CONCLUSIONS

Carotid artery 18FDG PET-CT imaging detected differences in vascular inflammation and early atherosclerosis between HIV-infected adults with CVD risk factors and healthy HIV-seronegative controls. These findings confirm the utility of this molecular level imaging approach for detecting and quantifying glucose uptake into inflammatory macrophages present in metabolically active, rupture-prone atherosclerotic plaques in HIV infected adults; a population with increased CVD risk.

Lipid profiles and oxidative stress parameters in male and female hemodialysis patients

To study atherogenesis markers in patients with stage 5D chronic kidney disease (CKD-5D) on hemodialysis to determine which parameters are modified and whether their behavior differ between male and female patients of similar age. Total cholesterol, triglycerides, glucose, total proteins, HDL-cholesterol, LDL-cholesterol, oxidative modification of low-density lipoprotein-cholesterol, autoantibodies against oxidized low-density lipoproteins-cholesterol, homocysteine (Hcy), folate, and vitamin B12 were measured in male and female controls and CKD-5D patients on hemodialysis for >6 months. The CKD-5D patients had significantly lower cholesterol, LDL-c and ox-LDL levels and significantly higher ox-LDL-AB and Hcy levels versus their respective controls. The reduction in ox-LDL in CKD patients does not imply a lower risk of atherosclerosis. In fact, the risk may be higher due to a greater capture of ox-LDL by macrophage scavenger receptors, which are increased in these patients. Elevated Hcy levels may also be a risk factor for atherosclerosis in male and female CKD-5D patients.

Poloxamer 407 increases soluble adhesion molecules, ICAM-1, VCAM-1 and E-selectin, in C57BL/6 mice

Objectives

Soluble shedded forms of cell adhesion molecules (sCAMs) found in plasma are regarded as surrogate markers for the cellular expression of CAMs. The presence of oxidised low-density lipoprotein (ox-LDL) cholesterol and fatty acids in the plasma, hypertriglyceridaemia and reduced plasma concentrations of high-density lipoprotein cholesterol (HDL-C) are all thought to stimulate an increase in the cellular expression of CAMs such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin. Our objectives were to determine how plasma levels of the soluble CAMs were modulated in a mouse model of dyslipidaemia induced chemically with poloxamer 407, and how these changes might be related to changes in the plasma concentrations of total cholesterol, HDL-C, non-HDL-C and triglycerides.

Methods

C57BL/6 mice were given a single intraperitoneal dose of poloxamer 407 (0.5 g/kg) and plasma concentrations of lipid fractions and sCAMs were measured at predetermined time points thereafter.

Key findings

The plasma concentrations of each sCAM were significantly increased in our mouse model of atherogenic dyslipidaemia compared with control mice administered saline, although the temporal relationship between the plasma sCAM concentration-time profiles and the plasma lipid concentration-time profiles were not coincident.

Conclusions

The atherogenic profile in our mouse model was associated with increases in the plasma concentrations of sICAM-1, sVCAM-1 and sE-selectin. These changes precede the formation of atherosclerotic lesions shown in previous work. This suggests the use of these sCAMs as biomarkers of future atheroma formation in this particular animal model.

Lipotoxicity in macrophages: evidence from diseases associated with the metabolic syndrome

Accumulation of lipid metabolites within non-adipose tissues can induce chronic inflammation by promoting macrophage infiltration and activation. Oxidized and glycated lipoproteins, free fatty acids, free cholesterol, triacylglycerols, diacylglycerols and ceramides have long been known to induce cellular dysfunction through their pro-inflammatory and pro-apoptotic properties. Emerging evidence suggests that macrophage activation by lipid metabolites and further modulation by lipid signaling represents a common pathogenic mechanism underlying lipotoxicity in atherosclerosis, obesity-associated insulin resistance and inflammatory diseases related to metabolic syndrome such as liver steatosis and chronic kidney disease. In this review, we discuss the latest discoveries that support the role of lipids in modulating the macrophage phenotype in different metabolic diseases. We describe the common mechanisms by which lipid derivatives, through modulation of macrophage function, promote plaque instability in the arterial wall, impair insulin responsiveness and contribute to inflammatory liver, muscle and kidney disease. We discuss the molecular mechanism of lipid activation of pro-inflammatory pathways (JNK, NFkappaB) and the key roles played by the PPAR and LXR nuclear receptors-lipid sensors that link lipid metabolism and inflammation.

Carbamylated low-density lipoprotein induces proliferation and increases adhesion molecule expression of human coronary artery smooth muscle cells

AIM

Presence of accelerated atherosclerosis in dialysis patients cannot be entirely explained by conventional risk factors. Exposure to urea, which is elevated in patients with kidney disease, leads to the carbamylation of proteins. We investigated the effects of carbamylated low-density lipoprotein (cLDL) on human coronary artery vascular smooth muscle cells (VSMC).

METHODS

Native LDL (nLDL) was carbamylated with potassium cyanate. Cells were incubated with different concentrations of cLDL carbamylated at different time points. Cytotoxicity, apoptosis, proliferation (bromodeoxyuridine incorporation), expression of adhesion molecules and extracellular matrix protein synthesis were studied.

RESULTS

Carbamylated low-density lipoprotein exposure leads to morphological alterations and presence of cellular debris. Neither nLDL nor cLDL caused apoptosis. Lactate dehydrogenase (LDH) release was not different between groups. Carbamylated low-density lipoprotein led to a striking proliferation in VSMC compared to nLDL. Carbamylated low-density lipoprotein significantly increased intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression compared to the control. The effects of cLDL on proliferation and adhesion molecule expression were dose-dependent and correlated with the degree of low-density lipoprotein carbamylation. cLDL had no effect on extracellular matrix protein synthesis.

CONCLUSION

The results support the hypothesis that cLDL may contribute to the pathogenesis of atherosclerosis in uraemic patients.

Markers of endothelial activity are related to components of the metabolic syndrome, but not to circulating concentrations of the advanced glycation end-product Nɛ-carboxymethyl-lysine in healthy Swedish men

Endothelial function is considered important in the development of cardiovascular diseases and type 2 diabetes. Circulating advanced glycation end-products (AGEs) and dietary components have been shown to affect endothelial function in type 2 diabetics, but determinants of endothelial function in a non-diabetic population are more poorly investigated. Therefore, we investigated relationships between dietary habits, AGEs and endothelial activation in men with isolated metabolic disturbances. Circulating markers of endothelial activation (soluble forms of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, E-selectin and von Willebrand factor) and plasma N epsilon-carboxymethyl-lysine (CML, the predominant AGE in human plasma) were analyzed in a cross-sectional study of 294 healthy men. Individuals completed a 7-day dietary record, and metabolic and inflammatory parameters were determined. NCEP/ATPIII-criteria were used to define the metabolic syndrome. Endothelial activation was higher in individuals with the metabolic syndrome, and was positively related to certain features of the syndrome (insulin, glucose, inflammation and obesity), but not to others (triacylglycerol and blood pressure). Dietary factors were related to endothelial activation, but CML was not. Multivariate analysis revealed energy and alcohol intake, along with insulin and markers of oxidative stress and inflammation, to be positive predictors of endothelial activation. In this cohort of otherwise healthy men, endothelial activation was increased in individuals with the full metabolic syndrome, but not in those with only some of the components of the metabolic syndrome. Insulin resistance, inflammation, oxidative stress, the dietary intake of energy and alcohol, but not plasma CML, predicted endothelial activation in these men.

Vasculoprotective potential of olive oil components

Epidemiological and clinical studies found that the traditional Mediterranean-style diet is associated with significantly lower mortality from coronary artery disease. Although it is difficult to isolate individual dietary factors, cumulative evidence suggests that olive oil, used as primary source of fat by Mediterranean populations, may play a key role in the observed cardiovascular benefit. Olive oil is a priceless source of vitamins and polyphenolic antioxidants, and has a balanced ratio of monounsaturated and polyunsaturated fatty acids. There are multiple mechanisms by which olive oil might impact the development of atherosclerosis. Olive oil decreases LDL-cholesterol and increases HDL-cholesterol, and also reduces oxidative stress due to polyphenols, which are able to scavenge free radicals and protect LDL from oxidation. In addition, olive oil components may interfere with the inflammatory response within atherosclerotic lesion, by inhibiting endothelial activation involved in monocyte recruitment during early atherogenesis and macrophage production of inflammatory cytokines and matrix degrading enzymes, thus improving vascular stability. Other vasculoprotective mechanisms by olive oil components derive from anti-thrombotic and anti-hypertensive actions. The available data support the need to preserve certain dietary traditions, such as olive oil consumption, to counteract the burden of cardiovascular disease.

Carbamylated Low-Density Lipoprotein Induces Monocyte Adhesion to Endothelial Cells Through Intercellular Adhesion Molecule-1 and Vascular Cell Adhesion Molecule-1

Objective— Carbamylated low-density lipoprotein (LDL), the most abundant modified LDL isoform in human blood, has been recently implicated in causing the atherosclerosis-prone injuries to endothelial cells in vitro and atherosclerosis in humans. This study was aimed at testing the hypothesis that carbamylated LDL acts via inducing monocyte adhesion to endothelial cells and determining the adhesion molecules responsible for the recruitment of monocytes.

Methods and Results— Exposure of human coronary artery endothelial cells with carbamylated LDL but not native LDL caused U937 monocyte adhesion and the induction of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 adhesion molecules as measured by cell enzyme-linked immunosorbent assay. Silencing of intercellular adhesion molecule-1 by siRNA or its inhibition using neutralizing antibody resulted in decreased monocyte adhesion to the endothelial cells. Similar silencing or neutralizing of vascular cell adhesion molecule-1 alone did not have an effect but was shown to contribute to intercellular adhesion molecule-1 when tested simultaneously.

Conclusions— Taken together, these data provide evidence that intercellular adhesion molecule-1 in cooperation with vascular cell adhesion molecule-1 are essential for monocyte adhesion by carbamylated low-density lipoprotein-activated human vascular endothelial cells in vitro.

Circulating levels of visfatin/pre-B-cell colony-enhancing factor 1 in relation to genotype, GFR, body composition, and survival in patients with CKD

BACKGROUND

Visfatin, also known as pre-B-cell colony-enhancing factor 1 (PBEF-1), recently was shown to be secreted from adipocytes and have insulin-mimetic properties in mice. Because renal failure per se is associated with both increased levels of circulating peptides and marked insulin resistance, even in the absence of diabetes mellitus, we hypothesized that visfatin could be a factor linking inflammation, kidney disease, and insulin resistance in this patient group.

METHODS

Altogether, we studied 189 patients with chronic kidney disease (CKD), comprising 149 patients with CKD stage 5 (glomerular filtration rate [GFR] < 15 mL/min; mean, 7 +/- 2 mL/min [<0.25 mL/s; mean, 0.12 +/- 0.03 mL/s]; 61% men; mean age, 54 +/- 12 years) and 40 patients with CKD stages 3 to 4 (GFR, 15 to 60 mL/min; mean, 33 +/- 21 mL/min [0.25 to 1.00 mL/s; mean, 0.55 +/- 0.35 mL/s]; 72% men; age, 59 +/- 15 years). We compared these with 30 randomly selected population controls (mean GFR, 85 +/- 16 mL/min [1.42 +/- 0.27 mL/s]; 69% men; age, 64 +/- 11 years). Serum visfatin was measured by using commercially available enzyme-linked immunosorbent assay, and we also performed genotyping of 3 verified polymorphisms in the visfatin gene (-423A/G, -1001T/G, and -1535C/T). Body fat was estimated by using dual-energy x-ray absorptiometry.

RESULTS

Serum visfatin levels were greater in patients with CKD stage 5 (41.3 +/- 18.0 ng/mL) than in those with CKD stages 3 to 4 (34.0 +/- 9.8 ng/mL; P < 0.01 versus CKD stage 5) or healthy controls (29.3 +/- 8.1 ng/mL; P < 0.0001). However, there were no significant differences between patients with and without diabetes, and the significant differences in circulating visfatin levels between genotypes disappeared after adjustment for differences in age, sex, GFR, and serum albumin level. In univariate analysis, visfatin level correlated with levels of GFR (rho = -0.22; P = 0.001), interleukin 6 (IL-6; rho = 0.17; P = 0.01), high-sensitivity C-reactive protein (rho = 0.14; rho < 0.05), and soluble vascular cell adhesion molecule 1 (sVCAM-1; rho = 0.39; P < 0.0001), but not total or truncal fat mass, insulin resistance, or hemoglobin A(1c) level. High plasma visfatin level predicted mortality in patients with CKD, also after adjustment for age and sex (likelihood ratio, 18.2; P < 0.0001), but not after additional correction for GFR, sVCAM-1, serum albumin, and serum IL-6 levels.

CONCLUSION

Circulating levels of the cytokine visfatin/PBEF-1 are influenced by renal function, but are not associated with fat mass or surrogate markers of insulin resistance in patients with CKD. Visfatin was associated independently with level of sVCAM-1, a marker of endothelial damage.

Role of vitamin E-coated membrane in reducing advanced glycation end products in hemodialysis patients: a pilot study

INTRODUCTION

Advanced glycation end products (AGEs) are markers of oxidative stress.

AIMS

To assess if a vitamin-E-coated dialyzer affects plasma AGE levels and endothelial function in hemodialysis patients.

METHODS

16 patients were dialyzed with a synthetic modified cellulose membrane (SMC, n = 8) or a vitamin E-coated dialyzer (n = 8), respectively. At week 32 endothelial function was determined as brachial artery flow-mediated dilatation (FMD). Total AGEs, free pentosidine (FP), protein-bound pentosidine (BP) and autoantibodies against oxidized LDL (ox-LDL-autoantibodies) were assessed at baseline (T0) and at 16, 32, 40 and 42 weeks (T16, T32, T40 and T42).

RESULTS

At T16 and T32 FP and BP were lower in vitamin E than in SMC (T 16: 88.7 +/- 8.96 vs. 124.2 +/- 11.90 pmol/ml plasma; p = 0.04, and 22.9 +/- 2.99 vs. 32.8 +/- 2.98 pmol/mg proteins; p = 0.04. T32: 78.7 +/- 8.54 vs. 123.7 +/- 10.15 pmol/ml plasma; p = 0.007, and 19.9 +/- 2.0 vs. 33.67 +/- 2.41 pmol/mg proteins; p = 0.001). In vitamin E, AGEs were lower at T32, T40 and T42 (946.7 +/- 80.91 vs. 1,351.2 +/- 179.33 AU/ml, p = 0.05; 986.9 +/- 59.63 vs. 1,509.9 +/- 154.17 AU/ml, p = 0.013; 890.3 +/- 73.70 vs. 1,453.9 +/- 153.16 AU/ml, p = 0.009). At T32 AGEs, ox-LDL autoantibodies and FMD were inversely correlated (R = -0.70 p = 0.007 and R = -0.59, p = 0.04, respectively).

CONCLUSIONS

Vit E-coated membrane reduces plasma AGEs levels and AGEs values are negatively correlated with FMD.

Upregulation of aortic adhesion molecules during aging

To investigate effects of aging on adhesion molecules (AMs), the present study assessed the expressions of aortic P-selectin and vascular adhesion molecule-1 (VCAM-1) in young (6-month-old) and old (24-month-old) Fischer 344 rats fed ad libitum (AL) or calorie-restricted diets. Results showed increased levels of aortic P-selectin and VCAM-1 in the old AL rats, causing excessive leukocyte infiltration as indicated by enhanced myeloperoxidase level. These elevations were parallel to increased oxidative stress including lipid peroxides during aging. Then involvement of redox-sensitive transcription factor nuclear factor-kappaB was analyzed, and greater activation of nuclear factor-kappaB-inducing kinase (NIK)/IkappaB kinase (IKK)/Inhibitor of kappaB (IkappaB) pathway in aorta from old AL rats was found. Further, in cultured endothelial cells challenged by various oxidative stimuli, the induced redox imbalance triggered overexpression and promoter activities of P-selectin and VCAM-1. Our study documented that aortic upregulated AMs with age are closely related to activation of NIK/IKK/IkappaB/nuclear factor-kappaB pathway brought on by oxidative stress.

Analysis of dyslipidemia in patients on chronic hemodialysis in Catalonia

Chronic hemodialysis patients show a high incidence and prevalence of cardiovascular disease of multifactorial etiology and an association between dyslipidemia and accelerated atherosclerosis. We analyzed characteristics of dyslipidemia in 1824 hemodialysis patients (59% men; mean age 65 +/- 15 years) in Catalonia and identified risk factors by logistic regression. Prevalence of dyslipidemia was high (63%). Most frequent lipid alterations were decreased HDL cholesterol (40%), hypertriglyceridemia (31%) and hypercholesterolemia (19%). Total cholesterol/HDL ratio was elevated in 23%. Body mass index (OR 1.08; 95% CI 1.05-1.11), diabetes mellitus (1.4; 1.09-1.79), ischemic heart disease (1.38, 1.08-1.75) and stroke (1.30; 1.0-1.69) were independent factors associated with dyslipidemia. Lengthy time (> 7 years) on dialysis (0.77; 0.59-0.99) and female sex (0.78; 0.64-0.96) were independent protective factors. A significant reduction in the risk of developing dyslipidemia was observed after the age of 50. Lipid-lowering drug use was low (19%), with statins being the most frequent (83%). The percentage of patients reaching target LDL levels according to individual cardiovascular risk (ATPIII) was unsatisfactory, particularly in high risk patients (52%). In light of the high prevalence of dyslipidemia and low adherence to target LDL goals, we conclude that strict control of dyslipidemia should be included in cardiovascular risk prevention strategies for chronic hemodialysis patients.

Circulating Oxidized Low-Density Lipoprotein and Its Association With Carotid Intima-Media Thickness in Asymptomatic Members of Familial Combined Hyperlipidemia Families

OBJECTIVE

Oxidized low-density lipoprotein (Ox-LDL)is implicated in the pathogenesis of atherosclerosis. Circulating oxidation-specific epitopes on plasma Ox-LDL has been linked with coronary artery disease, but its determinants and its association with early development of atherosclerosis in familial combined hyperlipidemia (FCHL) has not been very well studied. This study aimed to investigate the determinants of the circulating Ox-LDL and the association between Ox-LDL and carotid intima-media thickness (IMT) in asymptomatic members of FCHL families.

METHODS AND RESULTS

Ox-LDL, susceptibility of LDL to oxidation in vitro, plasma 8-isoprostane and antioxidants, lipids and lipoproteins, LDL particle size, and carotid IMT were measured in 150 asymptomatic FCHL family members. Affected FCHL family members had reduced LDL particle size and lag time for LDL oxidation, increased plasma levels of Ox-LDL, increased plasma urate and alpha-tocopherol, and a trend for the increase of 8-isoprostane as compared with nonaffected FCHL. Ox-LDL was independently associated with serum LDL cholesterol, apoB, and 8-isoprostane in multivariate analysis but only univariately correlated with LDL particle size and lag time for LDL oxidation. In addition, Ox-LDL was significantly associated with carotid mean IMT independently of other clinical and biochemical variables in a multivariate model.

CONCLUSIONS

Serum LDL cholesterol, apoB levels, and 8-isoprostane were the most important determinants of Ox-LDL. Ox-LDL is independently associated with carotid IMT in asymptomatic FCHL family members and can be used as a marker of early atherosclerosis in FCHL.

Associations among oxidized low-density lipoprotein antibody, C-reactive protein, interleukin-6, and circulating cell adhesion molecules in patients with unstable angina pectoris

Oxidized low-density lipoprotein (LDL) is believed to play a key role in the development of atherosclerosis. However, the significance of anti-oxidized LDL antibody in atherogenesis is unclear. The purposes of this study were to assess whether anti-oxidized LDL antibody titers are related to other inflammatory markers of possible interest in atherosclerotic development, such as soluble cell adhesion molecules, interleukin-6, and C-reactive protein (CRP), and to determine the prognostic value of anti-oxidized LDL antibody as a predictor of cardiac events in patients with unstable angina pectoris. Sixty patients (35 men and 25 women; mean age 60 years) with unstable angina were included in this study. The levels of CRP and of intercellular adhesion molecule-1 (ICAM-1) at 24 and 72 hours after admission were significantly higher than their baseline levels (p <0.05, respectively). After adjusting for age, gender, body mass index, and statin use, anti-oxidized LDL antibodies were positively correlated with CRP (r = 0.72, p <0.001) and ICAM-1 (r = 0.68, p <0.001). Elevated anti-oxidized LDL antibodies (mean >11.37 U/ml) and CRP levels (median >2.4 mg/L) on admission were correlated with a significantly lower 16-month, event-free survival rate (Kaplan-Meier event-free survival analysis, log-rank p <0.01 and p <0.05, respectively). Multivariate analysis by logistic regression revealed that elevated levels of anti-oxidized LDL antibody (mean >11.3 U/ml) on admission were an independent risk factor for an adverse cardiac event (odds ratio 2.2, 95% confidence interval 1.5 to 10.7, p = 0.001). This study demonstrates that anti-oxidized LDL antibody expression is associated with the expression of CRP and adhesion molecules, especially ICAM-1, and is a predictor of cardiac events in patients with unstable angina pectoris. The observed elevated levels of anti-oxidized LDL antibody suggest plaque instability and may be useful for identifying patients at higher risk of a cardiac event.

RENAL RESEARCH INSTITUTE SYMPOSIUM: Efforts to Determine the Role of Oxidant Stress in Dialysis Outcomes

The role of elevated markers of oxidant stress needs to be established in longitudinal studies. Oxidant stress markers such as malonaldehyde (MDA), isoprostanes, and breath hydrocarbons warrant rigorous application to outcomes, if they are to be used as clinical parameters. For example, investigations of C-reactive protein (CRP), parathyroid hormone (PTH), and several other clinical indicators have shown that these markers can be used to predict outcomes such as morbidity and mortality. Long-term followup is needed for intervention studies with antioxidants, since effects with short-term studies may be focused on critically-ill individuals where intervention would not be expected to be effective. Oxidant stress studies in this population especially need a long-term approach to test the hypothesis that antioxidant intervention is beneficial.

Lipoprotein alterations in hemodialysis: differences between diabetic and nondiabetic patients

Both renal failure and type 2 diabetes may contribute synergistically to the dyslipemia of diabetic renal failure with the development of atherosclerosis as the possible consequence. It has not yet been conclusively evaluated whether diabetic patients with end-stage renal failure under maintenance hemodialysis (HD) show accentuated alterations in plasma lipids and lipoproteins in comparison to nondiabetics under HD. These abnormalities would involve hepatic lipase activity and the regulation of triglyceride-rich lipoprotein metabolism. The purpose of the present study was to evaluate whether type 2 diabetic patients undergoing HD exhibited a lipid-lipoprotein profile different from that of nondiabetic hemodialyzed patients. We compared plasma lipids, apoprotein (apo) A-I and B, and lipoprotein parameters among 3 groups: 25 type 2 diabetics, 25 nondiabetics, both undergoing HD, and 20 healthy control subjects. Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) were isolated by sequential ultracentrifugation. Hepatic lipase activity was measured in postheparin plasma. Both groups of HD patients showed higher triglyceride and IDL cholesterol (P <.001), and lower high-density lipoprotein (HDL) cholesterol (P <.01) and apo A-I (P <.001) levels compared to the control group, even after adjustment for age and body mass index (BMI). However, no differences were found in lipid, lipoprotein, and apoprotein concentrations between diabetic and nondiabetic HD patients, except for high LDL triglyceride content of diabetic HD patients (P <.01). Nondiabetics undergoing HD also presented higher LDL triglyceride levels than controls (P <.05). LDL triglyceride correlated with plasma triglycerides (r = 0.51, P <.001). A lower LDL cholesterol/apo B ratio was found in each group of HD patients in comparison to controls (P <.02). Comparing the diabetic and nondiabetic patients, hepatic lipase activity remained unchanged, but significantly lower than control subjects (P <.001). Hepatic lipase correlated with log-triglyceride (r = -0.31, P <.01), IDL cholesterol (r = -0.41, P <.001), and LDL triglyceride (r = -0.32, P <.01). In conclusion, both diabetic and nondiabetic HD patients shared unfavorable alterations in lipid-lipoprotein profile not different between them but different from a healthy control group. The only difference between the groups of HD patients was a significant LDL triglyceride enrichment, which correlated negatively with hepatic lipase activity. Lipoprotein abnormalities in HD patients would enhance their risk for the development of atherosclerosis.

Increased levels of low-density lipoprotein oxidation in patients with familial hypercholesterolemia and in end-stage renal disease patients on hemodialysis

Patients with familial hypercholesterolemia (FH) and patients with end-stage renal disease (ESRD) undergoing dialysis suffer from accelerated atherosclerosis. Oxidation of low-density lipoprotein (LDL) cholesterol is crucial in atherogenesis. In the present study, we determined the LDL oxidation level and oxidizability of isolated LDL of 11 male patients with FH, 15 male ESRD patients on hemodialysis, and 15 age-matched male normolipidemic healthy controls. FH patients were without lipid-lowering medication for at least 4 weeks and were reassessed after 2 years of cholesterol-lowering therapy (statins). LDL oxidation level was measured by ELISA using monoclonal antibody 4E6 to oxidized LDL (oxLDL) as the capture antibody and anti-human apoB antibody for detection; results were expressed as percentage oxLDL. In FH patients and in ESRD patients on hemodialysis, both groups having a higher percentage of cardiovascular disease, mean plasma LDL oxidation levels were significantly elevated compared with controls (4.9 +/- 1.3; 3.7 +/- 2.0; 1.7 +/- 0.6%, respectively). Within each group of subjects, LDL oxidation level was not associated with history of cardiovascular disease. Furthermore, in neither group was a significant correlation found between plasma concentration of LDL cholesterol and LDL oxidation level. After cholesterol-lowering therapy, LDL oxidation level in FH patients had not changed significantly and remained elevated compared with controls, despite a reduction of LDL cholesterol by 55% on average. Also, absolute plasma oxLDL concentrations, obtained by multiplying LDL oxidation level with plasma LDL cholesterol concentration, were significantly higher in FH patients before and after cholesterol-lowering therapy and in ESRD patients on hemodialysis than in controls (489 +/- 145; 189 +/- 122; 100 +/- 65; and 59 +/- 27 micro moles/L, respectively). No correlation was found between plasma oxLDL concentration and parameters of LDL oxidizability, LDL fatty acids, and LDL alpha-tocopherol content. We conclude that cholesterol-lowering therapy does not normalize elevated LDL oxidation levels in FH patients and elevated LDL oxidation level in FH and in ESRD might mirror atherosclerosis.

Antibody to oxidized low-density lipoprotein and cardiovascular mortality in end-stage renal disease

BACKGROUND

Immune response to oxidized low-density lipoprotein (oxLDL) may modulate the process of atherogenesis and cardiovascular disease.

METHODS

We performed a prospective, observational cohort study in 249 patients with end-stage renal disease (ESRD) to examine whether the serum titer of anti-oxLDL antibody can predict cardiovascular mortality.

RESULTS

The median anti-oxLDL antibody titer was 320 mU/mL at baseline. During the follow-up (63 +/- 23 months), 72 deaths including 34 cardiovascular deaths occurred. When the subjects were divided into two groups by the median titer, the high titer group showed a lower risk for cardiovascular mortality (P = 0.040 by Kaplan-Meier analysis and log-rank test). Multivariate Cox proportional hazards model indicated that the lower risk of cardiovascular death in the high titer group remained significant (hazard ratio of 0.46, 95%CI 0.23-0.95, P = 0.037) and independent of age, presence of vascular complications, presence of diabetes mellitus, and elevated C-reactive protein. In contrast, anti-oxLDL antibody titer was not associated with non-cardiovascular mortality.

CONCLUSIONS

These results demonstrate, to our knowledge for the first time, that serum anti-oxLDL antibody titer is an independent predictor of cardiovascular mortality in a cohort of patients with ESRD.

Serum levels of antibodies against oxidised LDL in kidney graft recipients

BACKGROUND/AIMS

Lipid abnormalities present in the post-transplant period may contribute to the development and progression of complications leading to graft and patient loss. In the present study serum levels of antibodies against oxidised LDL (Ab-oxLDL) in kidney graft recipients were investigated along with their possible relation to the development of complications in the post-transplant period, and to the outcome of kidney transplantation.

METHODS

Serum levels of Ab-oxLDL and lipid pattern were evaluated in 92 kidney graft recipients before and at 3, 6, 12, and 24 months after kidney transplantation, as well as in 90 healthy blood donors (control group).

RESULTS

Kidney graft recipients had higher frequency of low levels of Ab-oxLDL as compared with the control group. A decrease in Ab-oxLDL levels was observed at 6 months post-transplant. Patients with early graft loss due to acute rejection had lower pre-transplant Ab-oxLDL levels (p < 0.05) as compared to patients with graft survival >3 months.

CONCLUSIONS

It is suggested that decreased Ab-oxLDL levels found in kidney graft recipients may reflect impaired response to the products of lipid oxidation or increased consumption of Ab-oxLDL, and are associated with graft loss due to acute rejection.

Accelerated atherosclerosis, dyslipidemia, and oxidative stress in end-stage renal disease

Premature atherosclerosis is a major cause of morbidity and mortality in end-stage renal disease patients. Dyslipidemia and increased oxidative stress contribute to premature atherogenesis in these patients. The dyslipidemia of end-stage renal disease consists of both quantitative and qualitative abnormalities in serum lipoproteins. Qualitative changes include hypertriglyceridemia (increased remnant lipoproteins), low high-density lipoprotein-cholesterol, and increased lipoprotein (a). In addition to quantitative changes, lipoproteins in end-stage renal disease undergo compositional and qualitative changes that make them pro-atherogenic, such as various modifications of apolipoprotein B, including oxidation, and modification by advanced glycation end-products. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and low-dose fibrates could be effective therapies for lipid disorders. The best evidence for increased oxidative stress in end-stage renal disease is the demonstration of increased plasma F2-isoprostanes. Confirmation of the positive findings with high-dose alpha-tocopherol in the Secondary Prevention with Antioxidants of Cardiovascular Disease in End-stage Renal Disease Study is urgently needed. Clinical trials with statins and other drugs that improve dyslipidemia also need to be undertaken. These therapies could clearly lead to a reduction in cardiovascular morbidity and mortality in these patients.