Atherogenic lipoprotein changes in the absence of hyperlipidemia in patients with chronic renal failure treated by hemodialysis

Clinical Significance of Intermediate-Density Lipoprotein Cholesterol Determination as a Predictor for Coronary Heart Disease Risk in Middle-Aged Men

Background: Not only low-density lipoprotein (LDL) cholesterol but also non-high-density lipoprotein cholesterol (non-HDL-C), very low-density lipoprotein (VLDL) cholesterol (VLDL-C), and intermediate-density lipoprotein (IDL) cholesterol (IDL-C) are reported to be significant risk markers for coronary heart disease (CHD). We reported the relevance of IDL-C to Framingham risk score (F-score), but the present study addressed the relevance of IDL-C to Suita score (S-score), a risk score for coronary heart disease (CHD) developed for the Japanese individuals in addition to F-score.

Methods: The cholesterol levels of lipoproteins, including triglyceride (TG)-rich lipoproteins (IDL and VLDL), were measured by an anion exchange high-performance liquid chromatography (AEX-HPLC). This study enrolled 476 men, aged mean 51 years and free of CHD and stroke.

Results: Non-HDL-C, IDL-C, and VLDL-C significantly correlated with F-score and S-score. In the multiple stepwise regression analysis, IDL-C as well as body mass index (BMI) significantly correlated with both F-score and S-score in both the total subjects and the subjects without drug therapy. The multivariate logistic analysis with the model composed of BMI and IDL-C as the predictor variables demonstrated that 1 SD increase in IDL-C was an independent predictor for 10-year CHD risk >10% of F-score (OR 1.534, 95% CI 1.266–1.859, p < 0001) and that of S-score (OR 1.372, 95% CI 1.130–1.667, p = 0.0014) in the total subjects. Even in the subjects without the drug therapy, the increased IDL-C, as well as BMI, were significant predictors for 10-year CHD risk >10% of S-score as well as F-score.

Conclusion: These results suggest the significant relevance of the increased IDL-C for CHD risk scores in middle-aged men free of CHD and stroke. Further investigations are needed in women and elderly subjects.

Statins for Treatment of Dyslipidemia in Chronic Kidney Disease

Dyslipidemia is a potent cardiovascular (CV) risk factor in the general population. Elevated low-density lipoprotein cholesterol (LDL-C) and/or low high-density lipoprotein (HDL-C) are well-established CV risk factors, but more precise determinants of risk include increased apoprotein B (ApoB), lipoprotein(a) [Lp(a)], intermediate and very low-density lipoprotein (IDL-C, VLDL-C; “remnant particles”), and small dense LDL particles. Lipoprotein metabolism is altered in association with declining glomerular filtration rate such that patients with non dialysis-dependent chronic kidney disease (CKD) have lower levels of HDL-C, higher triglyceride, ApoB, remnant IDL-C, remnant VLDL-C, and Lp(a), and a greater proportion of oxidized LDL-C. Similar abnormalities are prevalent in hemodialysis (HD) patients, who often manifest proatherogenic changes in LDL-C in the absence of increased levels. Patients treated with peritoneal dialysis (PD) have a similar but more severe dyslipidemia compared to HD patients due to stimulation of hepatic lipoprotein synthesis by glucose absorption from dialysate, increased insulin levels, and selective protein loss in the dialysate analogous to the nephrotic syndrome. In the dialysis-dependent CKD population, total cholesterol is directly associated with increased mortality after controlling for the presence of malnutrition–inflammation.

Treatment with statins reduces CV mortality in the general population by approximately one third, irrespective of baseline LDL-C or prior CV events. Statins have similar, if not greater, efficacy in altering the lipid profile in patients with dialysis-dependent CKD (HD and PD) compared to those with normal renal function, and are well tolerated in CKD patients at moderate doses (≤ 20 mg/day atorvastatin or simvastatin). Statins reduce C-reactive protein as well as lipid moieties such as ApoB, remnants IDL and VLDL-C, and oxidized and small dense LDL-C fraction. Large observational studies demonstrate that statin treatment is independently associated with a 30% – 50% mortality reduction in patients with dialysis-dependent CKD (similar between HD- and PD-treated patients). One recent randomized controlled trial evaluated the ability of statin treatment to reduce mortality in type II diabetics treated with HD (“4D”); the primary end point of death from cardiac cause, myocardial infarction, and stroke was not significantly reduced. However, results of this trial may not apply to other end-stage renal disease populations. Two ongoing randomized controlled trials (SHARP and AURORA) are underway evaluating the effect of statins on CV events and death in patients with CKD (including patients treated with HD and PD). Recruitment to future trials should be given a high priority by nephrologists and, until more data are available, consideration should be given to following published guidelines for the treatment of dyslipidemia in CKD. Additional consideration could be given to treating all dialysis patients felt to be at risk of CV disease (irrespective of cholesterol level), given the safety and potential efficacy of statins. This is especially relevant in patients treated with PD, given their more atherogenic lipid profile and the lack of randomized controlled trials in this population.

Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.

Supplementary nutrients for prevention of vascular calcification in patients with chronic kidney disease

Vascular calcification (VC) and malnutrition associated with cardiovascular disease are common in patients with chronic kidney disease (CKD) treated with dialysis. VC, which reflects vascular aging, and malnutrition are also encountered in the non-CKD elderly population. This similarity of clinical findings suggests that the progression of CKD is related to aging and the existence of a causal relationship between VC and malnutrition. To retard renal progression, a low- or very-low-protein diet is usually recommended for CKD patients. Dietary education may induce malnutrition and deficiency of important nutrients, such as vitamins K and D. Menaquinone-7, a type of vitamin K2, is under investigation for inhibiting VC in elderly patients without CKD, as well as for prevention of VC in patients with CKD. Nutritional vitamin D, such as cholecalciferol, may be considered to decrease the required dose of active vitamin D, which increases the risk of VC due to increased calcium and phosphate loads. Omega-3 fatty acids are important nutrients and their ability to inhibit VC needs to be evaluated in clinical trials. This review focuses on the ability of supplementary nutrients to prevent VC in patients with CKD, in whom dietary restriction is essential.

Managing Diabetes and Cardiovascular Risk in Chronic Kidney Disease Patients

We discuss mechanisms of increased cardiovascular disease (CVD) in patients with chronic kidney disease (CKD) and strategies for managing cardiovascular (CV) risk in these patients. Our focus was mainly on decreasing CV events and progression of microvascular complications by reducing levels of glucose and lipids. We searched PubMed with no limit on the date of the article. All articles were discussed among all authors. We chose pertinent articles, and searched their references in turn for additional relevant publications.

Treatment of Dyslipidemia in Chronic Kidney Disease

Dyslipidemia is a common feature of various renal diseases. This perturbed lipid metabolism results in accelerated atherosclerosis and increased cardiovascular morbidity and mortality. Treatment of dyslipidemia, in addition to normalization of blood pressure and reduction of proteinuria, could provide additional means to retard the progression of chronic renal insufficiency. Possible therapeutic approaches include mainly dietary and life-style modifications, selective use of some technical components of dialysis systems, and the judicious prescriptions of lipid-lowering drugs. Even with relatively normal lipid and lipoprotein profiles statin therapy seems to prevent atherogenesis acceleration. A wide range of therapeutic interventions, targeting the lipid abnormalities that may develop in chronic renal patients and end-stage renal disease (ESRD) are currently available, though still without convincing evidence based on long-term prospective studies which clearly demonstrate a significant reduction in cardiovascular morbidity and mortality of ESRD patients. However, extensive investigations, concerning the best long-term therapeutic strategy for this high-risk population of patients, are still missing.

Dyslipidemia in patients with chronic kidney disease: etiology and management

Patients with chronic kidney disease (CKD), including those with end-stage renal disease, treated with dialysis, or renal transplant recipients have an increased risk for cardiovascular disease (CVD) morbidity and mortality. Dyslipidemia, often present in this patient population, is an important risk factor for CVD development. Specific quantitative and qualitative changes are seen at different stages of renal impairment and are associated with the degree of glomerular filtration rate declining. Patients with non-dialysis-dependent CKD have low high-density lipoproteins (HDL), normal or low total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol, increased triglycerides as well as increased apolipoprotein B (apoB), lipoprotein(a) (Lp (a)), intermediate- and very-low-density lipoprotein (IDL, VLDL; “remnant particles”), and small dense LDL particles. In patients with nephrotic syndrome lipid profile is more atherogenic with increased TC, LDL, and triglycerides. Lipid profile in hemodialysis (HD) patients is usually similar to that in non-dialysis-dependent CKD patients. Patients on peritoneal dialysis (PD) have more altered dyslipidemia compared to HD patients, which is more atherogenic in nature. These differences may be attributed to PD per se but may also be associated with the selection of dialytic modality. In renal transplant recipients, TC, LDL, VLDL, and triglycerides are elevated, whereas HDL is significantly reduced. Many factors can influence post-transplant dyslipidemia including immunosuppressive agents. This patient population is obviously at high risk; hence, prompt diagnosis and management are required to improve their clinical outcomes. Various studies have shown statins to be effective in the cardiovascular risk reduction in patients with mild-to-moderate CKD as well as in renal transplant recipients. However, according to recent clinical randomized controlled trials (4D, A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Dialysis: an Assessment of Survival and Cardiovascular Events, and Study of Heart and Renal protection), these beneficial effects are uncertain in dialyzed patients. Therefore, further research for the most suitable treatment options is needed.

The serum lipids levels may be underestimated in patients on hemodialysis

OBJECTIVE

Although lipid disorders are a well-known risk factor for cardiovascular disease (CVD) in the general population, the optimal management with lipid-lowering therapy to reduce CVD risks and mortality in hemodialysis (HD) patients remains controversial. In the clinical setting, dyslipidemia can be diagnosed based on the detection of elevated lipid concentrations at the beginning of HD. This study investigated changes in the levels of serum lipids during a single HD session.

METHODS

The serum total cholesterol, triglyceride and high-density lipoprotein (HDL) cholesterol levels were measured in 31 HD patients at zero, two and four hours after the beginning of a single HD session. The data were analyzed using the Wilcoxon signed-rank test, a linear mixed model and Spearman's rank correlation analysis.

RESULTS

The serum total cholesterol, HDL cholesterol and non-HDL cholesterol levels increased significantly during the HD session. Even after the lipid parameters were corrected for changes in the total protein level, the total cholesterol and HDL cholesterol levels increased, whereas the non-HDL cholesterol levels did not change significantly. The percentage change in the serum levels of these lipid fractions correlated strongly with the percentage change in the ultrafiltration volume per body weight. In contrast, the serum triglyceride levels were decreased significantly at two hours compared with the levels noted at the beginning of HD and gradually increased at four hours.

CONCLUSION

The serum lipid levels are influenced significantly by HD treatment and ultrafiltration. Evaluating the degree of dyslipidemia at the beginning of a HD session may therefore underestimate the levels of serum lipids in HD patients with a large amount of weight gain, thus resulting in the use of insufficient lipid-lowering therapy.

Dyslipidemia in patients with chronic and end-stage kidney disease

In this review, we discuss the physiology, diagnosis and treatment of dyslipidemia in patients with chronic and end-stage renal disease. The recent important clinical trials in patients with chronic kidney disease and dyslipidemia are reviewed. Because of the lack of evidence in treating lipid abnormalities in this specific patient population, we propose that future studies should focus on the pathophysiological mechanisms and treatment of dyslipidemia in this special patient population.

Physical activity and blood lipids and lipoproteins in dialysis patients

The relationship between physical activity and blood lipids and lipoproteins in dialysis patients is reviewed in the context of the potentially confounding factors such as nutritional intake, cigarette smoking, obesity, alcohol intake, and physical activity levels in the general population and additional confounding factors such as mode of dialysis and diabetes in dialysis patients. The known associations in the general population of physical activity with high-density-lipoprotein cholesterol subfractions and apolipoprotein A-I are more pronounced in hemodialysis patients than in peritoneal dialysis patients even after adjusting for these confounding factors. Examining studies on the effects of physical activity on blood lipids and lipoproteins, the most consistent observation is the noted decrease in triglycerides and increase in high-density-lipoprotein cholesterol and insulin sensitivity in hemodialysis patients. The changes in lipids and lipoproteins in hemodialysis patients could be caused by changes in activity levels of lipoprotein lipase, insulin sensitivity, and/or glucose metabolism. Future research investigating the relationship between physical activity and blood lipids and lipoproteins in dialysis patients should direct research towards the underlying mechanisms for changes in blood lipids and lipoproteins.

Coronary artery calcification score is associated with mortality in Japanese hemodialysis patients

OBJECTIVE

Coronary artery calcification has been associated with higher mortality in coronary artery disease and chronic kidney disease. This study aimed to correlate coronary artery calcification score (CACS) with all-cause and cardiovascular mortalities in hemodialysis (HD) patients.

DESIGN, SETTING, SUBJECTS

A survival analysis was conducted in 200 HD patients. CACS was assessed by multidetector-row computed tomography and stratified as tertiles: group 1 (0∼105 U), group 2 (110∼1067 U), and group 3 (1094∼15481 U). The duration of follow-up was 7 years and 4 months. Kaplan-Meier method and Cox proportional hazard analysis adjusted for age and HD duration were performed to examine the impact of CACS on survival.

MAIN OUTCOME MEASURE

All-cause and cardiovascular mortalities were measured.

RESULTS

The cumulative all-cause and cardiovascular mortalities of group 1 were significantly lower than those of groups 2 and 3 (all-cause mortality: 7.6% vs. 43.3% and 52.2%, respectively, cardiovascular mortality: 3.0% vs. 22.4% and 26.9%, respectively). Cox proportional hazard analysis adjusted for age and HD duration revealed that all-cause and cardiovascular mortalities of group 1 were significantly lower than those of groups 2 and 3.

CONCLUSION

CACS is helpful to predict prognosis of HD patients independently of age and HD duration.

Association between vascular calcification scores on plain radiographs and fatty acid contents of erythrocyte membrane in hemodialysis patients

OBJECTIVE

Vascular calcification (VC) scores determined by using simple plain radiographic films are known to be associated with coronary artery disease and mortality in patients undergoing hemodialysis (HD). Omega-3 fatty acid (FA) has been shown to reduce ectopic calcifications in an animal model, and it has also been shown that erythrocyte membrane omega-3 FA content is an independent discriminator of coronary artery disease. The present study was designed to demonstrate relations between VC scores and erythrocyte membrane FA contents in patients undergoing HD.

DESIGN

A cross-sectional study was carried out.

SETTING

The study was carried out at an outpatient hemodialysis unit at Dong-A University Hospital, Busan, Republic of Korea.

PATIENTS

A total of 31 patients undergoing HD were recruited. Patients with significant malnutrition, a short duration of dialysis (<12 months), a history of recent infection, malignancy, or liver disease were excluded.

MAIN OUTCOME MEASURES

Plain radiographic films of the feet, hands, pelvis, and lateral lumbar spine were examined and VC scores were determined using previously reported methods. Erythrocyte membrane FA contents were analyzed by gas chromatography.

RESULTS

The erythrocyte membrane contents of eicosapentaenoic acid and docosahexaenoic acid were not found to be related with VC on simple plain radiographic films. However, erythrocyte membrane contents of oleic acid and total monounsaturated FA (MUFA) were significantly higher in patients with significant VC scores. Furthermore, erythrocyte membrane contents of MUFA and oleic acid were found to be negatively associated with high-density lipoprotein cholesterol level and positively associated with triglyceride level.

CONCLUSION

Erythrocyte membrane contents of MUFA and oleic acid were found to be associated with VC scores determined using plain radiographs and with dyslipidemia in patients undergoing HD.

Impact of statins on cardiovascular outcomes in renal transplant recipients: a systematic review

Patients with chronic kidney disease including renal transplant recipients (RTRs) have a markedly higher prevalence of cardiovascular disease than the general population. Many trials have established the role of statins in the prevention of cardiovascular mortality, not only by decreasing the low density lipoprotein-cholesterol levels but also by their pleotropic effects. These data from the general population may not be applicable to RTRs as these patients have different cardiovascular risk profiles. Till date, only a few prospective, randomized trials have assessed the use of statins in RTRs with regards to cardiovascular outcomes. The Assessment of Lescol in Renal Transplant trial, the largest trial so far, suggested that dyslipidemia management with statins in RTRs is associated with a significant reduction in the incidence of cardiac death and nonfatal myocardial infarction (although differences in the combined primary end point were not statistically significant). The current guidelines from National Kidney Foundation for managing dyslipidemia in RTRs recommend managing all chronic kidney disease patients as a coronary heart disease equivalent. The task group for drafting these guidelines concluded that based on the currently available evidence, additional studies may be needed in RTRs to confirm and extend the results of Assessment of Lescol in Renal Transplant trial.

Estimation of VLDL, IDL, LDL, HDL2, apoA-I, and apoB from the Friedewald inputs--apoB and IDL, but not LDL, are associated with mortality in type 1 diabetes

BACKGROUND

There is an unmet need for a straightforward and cost-effective assessment of multiple lipoprotein risk factors for vascular diseases.

AIMS

1) To study the relation of various lipoprotein lipid and apolipoprotein (apo) measures on the Friedewald inputs, i.e. plasma triglycerides (TG), cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C). 2) To build up regression models for the appropriate measures based solely on the Friedewald inputs.

METHODS

Data were available for 1,775 plasma samples, from which very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), low-density lipoprotein (LDL), and HDL were also isolated by ultracentrifugation. For HDL(2)-C and apolipoproteins, 343 and 247 samples were available, respectively.

RESULTS

Accurate models were obtained for VLDL-TG (cross-validation r=0.98), LDL-C (r=0.91), HDL(2)-C (r=0.92), apoA-I (r=0.92), and apoB (r=0.95). A semi-quantitative model was obtained for IDL-C (r=0.78). Due to the anticipated role of IDL-C in atherosclerosis, it was still kept within the accepted models and pursued further. The associations of the estimates with premature deaths were studied in 4,084 patients with type 1 diabetes. The associations of IDL-C and LDL-C were markedly different, the best predictors of mortality being apoB, apoB to apoA-I ratio, and IDL-C.

CONCLUSIONS

The new models allow identification of clinically relevant lipoprotein profiles with no added cost to the conventional Friedewald formula.

Measurement of cholesterol concentrations of major serum lipoprotein classes in haemodialysis patients by anion-exchange chromatography

BACKGROUND

Increased triglyceride (TG)-rich lipoproteins and decreased HDL that are implicated in the progression of atherosclerotic vascular diseases, are present in serum samples of patients undergoing haemodialysis (HD) therapy. Therefore, it is important to measure serum TG-rich lipoprotein concentrations to prevent the diseases.

METHODS

The cholesterol concentrations of lipoprotein classes in serum samples from the HD patients (n = 18) and healthy subjects (n = 18) were analysed by our recently developed method of high-performance liquid chromatography (HPLC), in which the lipoprotein classes were separated using an anion-exchange column, and the cholesterol concentrations of each of those were measured enzymatically using a post-column reaction. The ability of fractionated lipoprotein cholesterol determination by this HPLC method is mostly equivalent to the determination ability of an ultracentrifugation (UC).

RESULTS

HDL, LDL, and TG-rich lipoproteins, i.e. IDL, VLDL and chylomicrons, were well separated in the chromatograms. HDL cholesterol concentrations in the HD patients were significantly lower than in the healthy subjects (P < 0.0001), and IDL cholesterol concentrations and VLDL cholesterol concentrations in the HD patients were significantly higher than in the healthy subjects (P < 0.05). Profiles of these measured lipoprotein values were consistent with the previously reported lipoprotein values, measured ultracentrifugally characteristic of HD patients.

CONCLUSION

These results suggest that the HPLC method may be sufficiently applied to the assessment of serum lipoprotein profile in HD patients in place of the other method including an UC.

Low-density lipoprotein oxidizability in children with chronic renal failure

BACKGROUND

In childhood, dyslipidemia and low-density lipoprotein (LDL) oxidation play an important role in the development of atherosclerosis. Alterations of these factors have been shown in adult uremic patients.

METHODS

Nine children affected by chronic renal failure (CRF; urinary tract malformation, n = 8; polycystic kidney disease, n = 1) were studied to investigate the abnormalities of plasma lipoprotein concentration and composition and to assess the susceptibility of LDL to oxidation. All patients with CRF were on conservative treatment and, after informed consent, underwent the evaluation of (i) quantitative and qualitative plasma lipid profile; (ii) lipoprotein oxidation in vitro; and (iii) lipoprotein anti-oxidant content. These results were compared to those of an age-matched control group of eight healthy children.

RESULTS

Total cholesterol, LDL and triglycerides were significantly higher in CRF than in the control group. The composition of lipoproteins was different in the two groups: the amount of anti-oxidant factors (alpha-, gamma-tocopherol and carotenoids) was different in CRF and normal controls children, while LDL susceptibility to oxidation was significantly higher in uremic children than in controls.

CONCLUSIONS

CRF patients, already before dialysis, have a higher LDL oxidizability due to an altered lipoprotein composition and a low anti-oxidant content; therefore they have higher risk factors for atherosclerosis. On the basis of these data, supplementation with anti-oxidants might be useful in CRF children, but further studies are needed to evaluate the efficacy and safety of this therapeutic intervention.

Small dense low-density lipoprotein cholesterol concentration and carotid atherosclerosis

Low-density lipoprotein cholesterol (LDL-C) and the small dense LDL (SdLDL) phenotype are both predictors for ischemic heart disease. We examined whether cholesterol of SdLDL (SdLDL-C) is more closely associated with carotid artery intima-media thickness (CA-IMT), a surrogate measure of atherosclerosis, than LDL-C and other lipid parameters. The subjects were 326 consecutive participants including those with dyslipidemia, diabetes mellitus, hypertension, chronic kidney disease, and smokers. SdLDL-C was quantified by a newly developed precipitation method, and CA-IMT by high-resolution B-mode ultrasound. In univariate analysis, CA-IMT was most strongly correlated with SdLDL-C (Spearman's r=0.441, P<0.001), followed by apolipoprotein (apo) B, LDL-C, non-high-density lipoprotein cholesterol (Non-HDL-C), and plasma triglycerides (TG). HDL-C and apo A-I correlated inversely with CA-IMT. Non-lipid variables that were associated with CA-IMT were age, sex, presence of diabetes mellitus, presence of hypertension, estimate glomerular filtration rate (eGFR), and C-reactive protein (CRP). Even after adjustment for age, sex, diabetes mellitus, hypertension, smoking, eGFR and CRP, the positive association of CA-IMT with SdLDL-C remained significant, and again stronger than the associations with others lipid parameters. Further analyses revealed that the level of SdLDL-C was elevated in subgroups of the subjects including men, older subjects, smokers, those with higher CRP levels, those with diabetes mellitus, and hypertensive patients. These results indicate that SdLDL-C was the best marker of carotid atherosclerosis among the lipid parameters tested, and suggest that quantitative measurement of SdLDL-C gives useful information in the risk assessment for atherosclerotic disease.

Effect of rosuvastatin on outcomes in chronic haemodialysis patients: baseline data from the AURORA study

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of death in patients with end-stage renal disease (ESRD).

AIMS

AURORA (A study to evaluate the Use of Rosuvastatin in subjects On Regular haemodialysis: an Assessment of survival and cardiovascular events) is the first large-scale international trial to assess the effects of statins on cardiovascular outcomes in patients with ESRD on chronic haemodialysis. Preliminary baseline data from the randomised population are presented.

METHODS

A total of 2,775 patients from 280 centres in 25 countries were randomised into the study. Patients aged 50-80 years on regular chronic haemodialysis for at least 3 months before screening were eligible for inclusion. They were randomised 1:1 to receive either rosuvastatin 10 mg or placebo daily and assessed throughout the study.

RESULTS

The mean age at baseline was 64 years. Most patients were male (62%) and 85% were white. The median time since commencing renal replacement was 32 months. Mean total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels were 4.53 mmol/l (175 mg/dl) and 2.57 mmol/l (99 mg/dl), respectively.

CONCLUSION

Results from the AURORA trial will impact on the current guidelines and use of statins in this patient population.

The unique character of cardiovascular disease in chronic kidney disease and its implications for treatment with lipid-lowering drugs

Although the risk for cardiovascular disease (CVD) is high in individuals with chronic kidney disease (CKD), there are very limited data to guide the use of lipid-lowering drugs (LLDs) in this population because the major trials of LLDs in the general population have included very few individuals with CKD. The pathophysiologic and epidemiologic differences of CVD in the CKD population suggest that the study findings derived in the general population may not be directly applicable to those with CKD, and the few trials that have been directed at patients with kidney disease have not shown clear clinical benefits of LLDs. The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) Work Group has provided consensus-based guidelines for managing dyslipidemias in individuals with CKD and after renal transplantation. Since the publication of these statements, further data have emerged and multiple studies are ongoing to define better the role of LLDs in patients with CKD. In this article, the data that are pertinent to the CKD population are reviewed, and updated recommendations for use of LLD in the CKD population are provided.

Atherosclerotic risk factors and carotid stiffness in elderly asymptomatic HD patients

Several studies showed that carotid atherosclerosis and stiffness are independent prognostic factors of cardiovascular morbidity and mortality in the general population and in end-stage renal disease patients. However, the impact of established risk factors on carotid structural and elastic properties in non-diabetic elderly hemodialysis patients with negative history for cardiovascular disease has not been fully elucidated. In this paper, we investigated the effect of established and potential risk factors on carotid atherosclerosis and stiffness. Thirty stable, non-symptomatic, non-diabetic patients, aged 65-years and older (mean age 71.4+/-4.15, range 65-79) on hemodialysis for more than 6 months, were included. All patients underwent B-mode ultrasonography of common carotid artery estimating intima-media wall thickness and wall-to-lumen ratio bilaterally and checking for the presence of plaques. Carotid elasticity was evaluated by compliance, distensibility, and the incremental elastic modulus (Einc), whereas systemic arterial stiffening was evaluated by the augmentation index provided by tonometry of radial artery. Our results showed that presence of carotid plaques and wall thickening were frequent findings in this population (76% and 73.3%, respectively) and they were positively associated with fibrinogen (P<0.005), diastolic blood pressure (P<0.004), visceral obesity (P<0.001) and bio-intact PTH (i-PTH) (P=0.03). Overall, systemic and carotid stiffness were strongly correlated with hs-CRP (P=0.018), serum ferritin (P=0.02) with age (P=0.03), lipids (P=0.03) and i-PTH (P=0.05). In conclusion, our findings show that stiffening and atherosclerosis in non-symptomatic elderly HD patients are very common and they are related not only to hemodynamic changes (diastolic blood pressure), inflammation (hs-CRP, fibrinogen, ferritin) or metabolic dysfunction (increased i-PTH, abnormal lipid profile), but also to abnormal fat deposition (increased waist to hip ratio and waist circumference). Considering the high morbidity and mortality of elderly patients, close monitoring of these parameters could be useful to prevent cardiovascular events.

Dyslipidemia, inflammation and dialysis outcomes: what we know now

PURPOSE OF REVIEW

The limited prognosis of patients with chronic kidney disease starts when renal function begins to decline.

RECENT FINDINGS

Available interventions did not prove their efficacy. Treatment of dyslipidemia and inflammation by statins was shown to be effective in post-hoc subgroup analyses of large-scale randomized controlled trials in patients with chronic kidney disease stages 2 and 3. So far, randomized controlled trials in dialysis patients (HEMO, ADEMEX, 4D study) and after kidney transplantation (ALERT study) have produced so-called 'negative results'. It is most likely that these trials had limited power to prove the primary hypothesis. It is also probable that cardiac disease in renal patients changes its character from a vascular atherosclerotic to a more complex structural heart disease in combination with stiff arteries (arteriosclerosis). Clinically, this leads to a high proportion of sudden cardiac deaths: of 270 cardiac deaths in the 4D trial, 160 were of sudden cardiac origin. A complex pathogenetic process and a number of new emerging cardiovascular disease risk factors in the setting of high-grade inflammation/infection are proposed as being responsible.

SUMMARY

This review focuses on outcome variables in diabetic hemodialysis patients with special focus on risk factors such as inflammation and dyslipidemia.

Effects of inflammation on plasma composition and endothelial structure and function

Changes in plasma protein composition normally associated with malnutrition, specifically hypoalbuminemia and reduced levels of tranferrin and prealbumin, usually only occur in the presence of preterminal starvation in the absence of inflammation. Thus, reduced levels of any of these proteins suggest that the inflammatory response has been activated. Inflammation also alters lipoprotein structure and function, and oxidation of low-density lipoprotein (LDL). This decreases high-density lipoprotein (HDL) levels and reduces its capacity to function as an antioxidant, and increases the levels of proteins, such as fibrinogen, associated with vascular disease. Cytokines and acute phase proteins, such as C-reactive protein (CRP), also up-regulate expression of adhesion molecules on the vascular endothelium, making them more effective targets for macrophage adhesion. Leukocyte-derived myeloperoxidase functions as an "NO oxidase" in the inflamed vasculature and contributes to decreased NO bioavailability and compromises vascular reactivity. The link between inflammation and apparent malnutrition explains the relationship between low levels of albumin, prealbumin, and transferrin with subsequent cardiovascular risk.

Why don't fistulas mature?

Fistula maturation requires a compliant and responsive vasculature capable of dilating in response to the increased velocity of blood flowing into the newly created low-resistance circuit. Successful maturation to a high volume flow circuit capable of sustaining hemodialysis typically occurs within the first few weeks after creation. Failure to achieve maturation within 4-8 weeks should prompt a search for reversible etiologies; however, an accepted definition of maturation, particularly for patients not yet on dialysis remains elusive. The most commonly identified etiology is neointimal hyperplasia typically occurring in the juxta-anastomotic vein. However, failed maturation has also been reported secondary to impaired arterial and venous dilation and accessory veins. The exact frequency of each of these etiologies is unclear. Understanding the etiologies of impaired fistula maturation will focus future studies of targeted interventions to improve the rate of fistula maturation and increase the number of dialysis patients with a functioning autogenous fistula.

Plasma Lipoprotein Abnormalities in Hemodialysis Patients—Clinical Implications and Therapeutic Guidelines

Patients with advanced stages of chronic kidney disease (CKD) have an increased risk of death from cardiovascular disease (CVD). Dyslipidemias are associated with atherosclerotic vascular changes and the risk of occurrence of acute myocardial infarction in hemodialysis patients. However, management of dyslipidemia in hemodialysis patients does not appear to be actively carried out in routine practice. Presumably, there are three reasons for this reluctance to lipid-lowering in hemodialysis patients. First, there are epidemiological data showing the inverse relationship between cholesterol and mortality rate; a high cholesterol predicts a better survival. Second, lipids are not usually measured using standard fasting serum, but a non-fasting specimen. Third, although hypertriglyceridemia is the most common abnormality, fibrates are contraindicated in patients with renal failure because of a high risk of rhabdomyolysis. These issues are discussed in the current review article. Based on published work, lipid lowering would not increase the death rate if carried out without worsening malnutrition. The National Kidney Foundation K/DOQI Clinical Practice Guidelines recommend a reduction in fasting LDL-C below 100 mg/dL for the prevention of CVD in dialysis patients. Practically, however, the use of non-HDL-C measured by casual blood samples might be sufficient for the risk assessment in many hemodialysis patients. Statins are a good choice for lipid-lowering in dialysis patients. Furthermore, lipoprotein profile might be improved by an inventive use of dialyzer membranes, dialysate solutions, and other dialysis-related medications. For severe hypercholesterolemia, LDL-apheresis is another choice for consideration. Further studies are needed to clearly prove the benefit of lipid reduction in hemodialysis patients and those with CKD at earlier stages.

Endocrinology and Dialysis Jean L. HolleySeries Editor: Lipid Abnormalities Associated with End-Stage Renal Disease

Patients undergoing chronic renal replacement therapy have a high incidence of dyslipidemia. In general, there are increased concentrations of triglyceride-rich apolipoprotein B-containing particles. These elevations lead to increased levels of non-high-density lipoprotein (HDL) levels. This pattern is further modified by the method of dialysis (peritoneal versus hemodialysis) and comorbidities such as diabetes. End-stage renal disease patients also demonstrate increased levels of lipoprotein(a) (Lp(a)) and oxidized low-density lipoprotein (LDL)both of which are highly atherogenic. This review focuses on the pathogenesis of these lipid abnormalities and their role in the atherosclerotic process.

Serum Lipid Profile Constituents as Markers of Cardiovascular Morbidity in Patients on Chronic Hemodialysis

We designed the present case-control study in order to examine the validity of apolipoprotein (apo) A-I, B, apoB/apoA-I ratio and Lp(a) as alternative markers of cardiovascular morbidity in end-stage renal disease (ESRD) patients undergoing chronic hemodialysis (HD). Twenty-five HD patients (18 males, mean age 63, range 52–69 years) comprised the group with prevalent cardiovascular disease (CVD) and 50 HD patients (35 males, mean age 62, range 40–77 years) with non evident cardiovascular disease history constituted the second study group. Patients with CVD had significantly higher concentrations of serum apoB, apoB/apoA-I ratio and Lp(a), and lower levels of apoA-I compared to patients without incident CVD. All three parameters studied were correlated with cardiovascular morbidity, i.e. apoA-I negatively and apoB and apoB/apoA-I ratio positively (r = −0.6, P < 0.05; r = 0.659, P < 0.01; and r = 0.614, P < 0.01, respectively). Furthermore, logCRP exhibited as well a significant positive correlation with cardiovascular morbidity (r = 0.704, P < 0.001), not this being the case for Lp(a) which was not found to exhibit such a correlation (r = 0.05, P = NS). Among them, apoB and apoB/apoA-I ratio exhibited the characteristics most coherent to CVD. The age- and sex-adjusted OR for the presence of CVD was 2.3 and 2.0, respectively, which remained independent of any confounding effect of inflammation. In conclusion, serum apoB levels and apoB/apoA-I ratio exhibit characteristics of credible independent markers of in HD patients.

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.

Association between Inflammation and Malnutrition as Risk Factors of Cardiovascular Disease

Cardiovascular disease is the leading cause of death among dialysis patients. The relative risk of mortality increases as serum albumin concentration and body mass index decline. While these are generally associated with nutritional status, inflammation causes sarcopenia and decreased albumin concentration by reducing synthesis of proteins and increasing their catabolic rate. While inflammation can arise from atherosclerotic blood vessels, systemic inflammation from any source can alter the vascular endothelium and plasma protein composition in ways that promotes vascular injury. High-density lipoprotein synthesis is decreased and the high-density lipoprotein present is less capable of reducing inflammation. Activation of neutrophils favors lipoprotein oxidation. Surprisingly, while obesity is associated with cytokine production in patients without renal failure, as well as among dialysis patients, increased body mass index, whether reflecting muscle mass or adipose tissue, is associated with a decline in mortality rates.

The effect of the initiation of renal replacement therapy on lipid profile and oxidative stress during the first 6 months of treatment

BACKGROUND

Disturbed lipoproteins and increased oxidative stress are two of the "non-traditional" cardiovascular risk factors in chronic renal failure. There are very few prospective data of the influence of dialysis on these two factors. In the present study we investigated the effects of the initiation of both hemo- and peritoneal dialysis therapy on lipoproteins and parameters of LDL oxidation.

METHODS

In this prospective cohort study, we assessed lipoproteins, plasma lipid peroxides and in vitro copper-induced LDL oxidation in 46 patients with end-stage renal disease prior to the start of dialysis and after 6 months of treatment with either hemodialysis (n=33) or peritoneal dialysis (n=13).

RESULTS

After 6 months of treatment with hemodialysis there was an increase in total cholesterol (4.6+/-1.1 vs. 5.0+/-1.3 mmol/l; p<0.05) and triglycerides (2.0+/-0.9 vs. 2.8+/-1.6 mmol/l; p<0.03). In the peritoneal dialysis group the lipoproteins did not change. Regarding lipid peroxides and in vitro copper-induced LDL oxidation, also no changes were observed after 6 months of treatment in both groups.

CONCLUSION

Dyslipidemia aggravates after 6 months of hemodialysis but not after 6 months of peritoneal dialysis. During this period, no net effects on oxidative stress were demonstrated.

Low doses of losartan and trandolapril improve arterial stiffness in hemodialysis patients

BACKGROUND

Hemodialysis patients have uremic dyslipidemia, represented by elevated serum intermediate-density lipoprotein cholesterol (IDL-C) levels, and an increased cardiovascular mortality rate. This study was performed to determine the low-dose effects of the angiotensin II receptor blocker losartan and the angiotensin-converting enzyme inhibitor trandolapril on pulse wave velocity (PWV), which predicts cardiovascular morbidity and mortality in hemodialysis patients.

METHODS

Serum lipid levels and PWV were monitored for 12 months in 64 hemodialysis patients who were administered low doses of losartan or trandolapril or a placebo.

RESULTS

At the start of the study, there were no differences in patient characteristics among the 3 groups. PWV tended to increase in the placebo group during the 12-month study period, but decreased significantly in the losartan and trandolapril groups, and decreases in PWV were similar in the losartan and trandolapril groups. There were no changes in blood pressure, hematocrit, erythropoietin dose, ankle-brachial index, serum lipid levels, serum 8-isoprostane levels, or serum C-reactive protein levels during the 12-month study period, but there was an increase in serum triglyceride levels in the losartan group and a decrease in serum IDL-C levels in the losartan and trandolapril groups.

CONCLUSION

In hemodialysis patients, trandolapril is as effective as losartan in decreasing PWV independent of its depressor effect and in suppressing elevated IDL-C levels. Long-term blockade of the renin-angiotensin system may have a beneficial effect on the acceleration of atherosclerosis and uremic dyslipidemia.

Newer Paradigms in Renal Replacement Therapy: Will They Alter Cardiovascular Outcomes?

Cardiovascular disease remains the leading cause of morbidity and mortality for patients with end-stage renal disease. Conventional hemodialysis has had limited impact on cardiovascular risk factors and mortality. Increasing evidence suggests that nocturnal home hemodialysis has beneficial effects on cardiovascular parameter outcomes. This article reviews the documented effects of nocturnal home hemodialysis on blood pressure control, cardiac geometry and left ventricular systolic function, lipid profiles, calcium-phosphate metabolism, parathyroid hormone levels, homocysteine levels, sleep apnea, and autonomic modulation of heart rate. It discusses possible mechanisms to explain these observed changes.

The role of the kidney in lipid metabolism

PURPOSE OF REVIEW

Cellular uptake of plasma lipids is to a large extent mediated by specific membrane-associated proteins that recognize lipid-protein complexes. In the kidney, the apical surface of proximal tubules has a high capacity for receptor-mediated uptake of filtered lipid-binding plasma proteins. We describe the renal receptor system and its role in lipid metabolism in health and disease, and discuss the general effect of the diseased kidney on lipid metabolism.

RECENT FINDINGS

Megalin and cubilin are receptors in the proximal tubules. An accumulating number of lipid-binding and regulating proteins (e.g. albumin, apolipoprotein A-I and leptin) have been identified as ligands, suggesting that their receptors may directly take up lipids in the proximal tubules and indirectly affect plasma and tissue lipid metabolism. Recently, the amnionless protein was shown to be essential for the membrane association and trafficking of cubilin.

SUMMARY

The kidney has a high capacity for uptake of lipid-binding proteins and lipid-regulating hormones via the megalin and cubilin/amnionless protein receptors. Although the glomerular filtration barrier prevents access of the large lipoprotein particles to the proximal tubules, the receptors may be exposed to lipids bound to filtered lipid-binding proteins not associated to lipoprotein particles. Renal filtration and receptor-mediated uptake of lipid-binding and lipid-regulating proteins may therefore influence overall lipid metabolism. The pathological mechanisms causing the pronounced atherosclerosis-promoting effect of uremia may involve impairment of this clearance pathway.

Effect of rosuvastatin on outcomes in chronic haemodialysis patients - design and rationale of the AURORA study

BACKGROUND

Patients with end-stage renal disease (ESRD) are at high risk of cardiovascular events. Multiple risk factors for atherosclerosis are present in ESRD and may contribute to the increased risk of cardiovascular mortality in this population. In contrast to patients with normal renal function, the benefits of modifying lipid levels on cardiovascular outcomes in patients with ESRD on haemodialysis have yet to be confirmed in large prospective randomised trials. A study to evaluate the Use of Rosuvastatin in subjects On Regular haemodialysis: an Assessment of survival and cardiovascular events (AURORA) will be the first large-scale international trial to assess the effects of statin therapy on cardiovascular morbidity and mortality in ESRD patients on chronic haemodialysis.

METHODS

More than 2,750 ESRD patients who have been receiving chronic haemodialysis treatment for at least 3 months have been randomised (1:1), irrespective of baseline lipid levels, to treatment with rosuvastatin 10 mg or placebo. The primary study endpoint is the time to a major cardiovascular event (first occurrence of cardiovascular death, non-fatal myocardial infarction or non-fatal stroke). Secondary endpoints include all-cause mortality, major cardiovascular event-free survival time, time to cardiovascular death, time to non-cardiovascular death, cardiovascular interventions, tolerability of treatment and health economic costs per life-year saved. Study medication will be given until 620 subjects have experienced a major cardiovascular event.

CONCLUSION

Our hypothesis is that results from AURORA will establish the clinical efficacy and tolerability of rosuvastatin in patients with ESRD receiving chronic haemodialysis and guide the optimal management of this expanding population.

Roles of metabolic and endocrinological alterations in atherosclerosis and cardiovascular disease in renal failure: another form of metabolic syndrome

Patients with end-stage renal disease have markedly increased risk for death from cardiovascular disease. Renal failure is associated with multiple metabolic and endocrinologic abnormalities, and these alterations are involved in advanced atherosclerosis and high cardiovascular risk. Increased insulin resistance index by homeostasis model assessment (HOMA-IR), a simple index of insulin resistance, was an independent predictor of cardiovascular mortality in nondiabetic patients on maintenance hemodialysis. Renal failure impairs lipoprotein metabolism leading to the atherogenic lipoprotein profile characterized by increased triglyceride-rich remnant lipoproteins such as intermediate-density lipoprotein, an independent factor of increased aortic stiffness. Non-high-density lipoprotein cholesterol, the sum of cholesterol of intermediate-density lipoprotein and other apoB-containing lipoproteins, is an independent factor associated with increased arterial thickness and a predictor of cardiovascular death in hemodialysis patients. The risk for cardiovascular death in hemodialysis patients is associated closely with hypertension and malnutrition, but not with obesity. The constellation of insulin resistance, dyslipidemia, hypertension, and malnutrition in renal failure suggests the presence of another type of metabolic syndrome promoting cardiovascular disease. In addition, vitamin D deficiency and abnormalities in calcium, phosphate, and parathyroid hormone levels increase the death risk from cardiovascular disease in renal failure. It is expected that treatment of these metabolic and endocrinologic alterations would improve the survival of patients with renal failure.

Effects of hemodialysis on serum lipids and phospholipids of end-stage renal failure patients

Patients with chronic renal failure undergoing periodic maintenance hemodialysis frequently present dyslipoproteinaemia which has been linked to the sharply increased risk of cardiovascular disease in these subjects. Reported defects on lipoprotein-related enzyme activities suggest a possible influence of hemodialysis not just to plasma lipid and lipoprotein levels but also to the composition of cell membranes. In this study, it was investigated whether the reported lipid abnormalities are accompanied by changes in serum phospholipids levels. Blood samples were obtained from 140 patients undergoing maintenance hemodialysis treatment and 122 normolipidemic healthy controls and analyzed for total serum phospholipids and their individual subclasses, as well as for total cholesterol and triglycerides, HDL-cholesterol and its subclasses. A significant decrease was observed in serum HDL cholesterol levels (p < 0.001) and its subclasses, HDL2-cholesterol (p < 0.01) and HDL3-cholesterol (p < 0.01) in patients when compared with healthy controls. A critical increase in the serum triglyceride content (p < 0.001) of patients was also observed. In addition, the serum levels of sphingomyelin (p < 0.01) and diphosphatidylglycerol (p < 0.001) were increased in the patient group, while the levels of phosphatidylcholine (p < 0.01) and phosphatidylinositol (p < 0.01) were significantly decreased in the patient group compared to healthy controls. In conclusion, this work clearly demonstrates that hemodialysis treatment contributes significantly to the dyslipidemic profile of end-stage renal failure patients by altering serum lipoprotein and phospholipids concentrations.

Effects of Atorvastatin on Low-Density Lipoprotein Cholesterol Phenotype and C-Reactive Protein Levels in Patients Undergoing Long-Term Dialysis

STUDY OBJECTIVES

To determine the effects of atorvastatin on low-density lipoprotein cholesterol (LDL) particle size and C-reactive protein (CRP) concentrations in patients undergoing long-term hemodialysis. Another objective was to compare the effects of atorvastatin on lipoprotein profiles as determined by direct versus indirect assessment of lipoprotein composition.

DESIGN

Randomized, parallel-group substudy.

SETTING

Two university-affiliated outpatient hemodialysis centers.

PATIENTS

Nineteen patients with LDL levels above 100 mg/dl and with at least two cardiovascular risk factors.

INTERVENTION

Patients were randomized in a 1:1 ratio to atorvastatin 10 mg/day or no treatment (control) for 20 weeks.

MEASUREMENTS AND MAIN RESULTS

We compared the differences between LDL particle size and CRP levels at baseline and 20 weeks in the atorvastatin versus control groups. Baseline demographic characteristics were similar between the two groups. Atorvastatin therapy was associated with no change in mean LDL particle size (p=0.23) and with a 90% decrease in mean CRP level (p=0.52). When evaluated by standard chemical analysis, atorvastatin therapy reduced total cholesterol levels by 29% (p=0.025) and resulted in nonsignificant reductions in LDL, high-density lipoprotein cholesterol, and triglyceride levels. Treatment with atorvastatin was not associated with significant changes in lipoprotein profile as determined by nuclear magnetic resonance (NMR) spectroscopy.

CONCLUSION

Treatment with atorvastatin did not affect LDL particle size but was associated with a sizable, yet nonsignificant, reduction in CRP concentrations. The drug had variable effects on lipoprotein concentrations as determined by chemical and NMR analytical methods. A larger study is necessary to provide definitive information on the effects of atorvastatin on LDL phenotype and CRP in patients with kidney disease.

Association of chronic kidney disease with clinical outcomes after coronary revascularization: the Arterial Revascularization Therapies Study (ARTS)

BACKGROUND

Chronic kidney disease (CKD) is associated with adverse outcomes after coronary artery bypass graft surgery (CABG) and percutaneous coronary interventions (PCI), but it is unclear which of these revascularization strategies is associated with lower risk for morbidity and mortality in this population. In the Arterial Revascularization Therapies Study (ARTS), we compared long-term clinical outcomes after CABG or PCI with multivessel stenting in patients with CKD.

METHODS

The ARTS randomly assigned 1205 participants with and without CKD to CABG or PCI with multivessel stenting. We defined CKD as creatinine clearance < or =60 mL/min, estimated by the Cockroft-Gault equation. The primary outcome was the composite of death, myocardial infarction (MI), or stroke; and, a secondary outcome was repeat revascularization. Participants were followed for a mean of 3 years after their intervention. We evaluated whether randomization to CABG or PCI was associated with different outcomes among participants with CKD.

RESULTS

Two hundred ninety participants (25%) had CKD at entry into ARTS. One hundred fifty-one received PCI, and 139 received CABG. No difference was observed in the primary endpoint with CABG or PCI among CKD participants (adjusted Hazard Ratio [HR] CABG vs PCI = 0.93; 95% CI 0.54-1.60; P = .97). However, CABG was associated with a reduced risk for repeat revascularization (HR = 0.28; 95% CI 0.14-0.54; P < .01). Compared with participants with normal renal function, CKD was associated with a nearly 2-fold risk for the primary outcome (unadjusted HR = 1.9; 95% CI 1.4-2.7; P < .01). After multivariate adjustment, this association remained significant (HR 1.6; 95% CI 1.1-2.4).

CONCLUSIONS

In patients with multivessel CAD and CKD, treatment with CABG or PCI with multivessel stenting led to similar outcomes of death, MI, or stroke, but CABG was associated with decreased repeat revascularizations. When compared with ARTS participants with normal renal function, those with CKD had substantially elevated risk of adverse clinical outcomes after coronary revascularization.

A rapid methodology for the isolation of intermediate-density lipoprotein: characterization of lipid composition and apoprotein content

BACKGROUND

Intermediate-density lipoprotein (IDL) is a structurally related precursor of low-density lipoprotein (LDL). Although found in significantly lower levels, extensive evidence suggests that IDL shares LDL's capacity to promote atherosclerosis. To assist further investigation into IDL's composition and physiological relevance, we have established a rapid method to extract IDL from plasma.

METHODS

IDL was isolated from plasma by sequential floatation ultracentrifugation in 3 h, a significantly shorter isolation time than previously published methods. Apoproteins (apo) B100, CIII, and E, together with the level of albumin contamination, were quantified using single radial immunodiffusion. The lipid composition of IDL was measured using automated enzyme assays.

RESULTS

The percent recovery of lipid from all lipoprotein fractions (VLDL+IDL+LDL+HDL) was 97.0+/-4.9% when compared to total plasma lipid. IDL had a reduced concentration of apo CIII, apo E, triglyceride, and free cholesterol, and had a higher concentration of apo B100, cholesterol ester, and phospholipid when compared to VLDL. Pure IDL migrated in advance of LDL during agarose electrophoresis.

CONCLUSIONS

This rapid technique minimizes damage to the integrity of IDL and yields sufficient quantities to allow accurate assessment of composition and susceptibility to in vitro oxidation, and thus facilitates further investigation of IDL in the development of atherosclerosis.

Chronic kidney disease as a metabolic syndrome with malnutrition--need for strict control of risk factors

Patients with chronic kidney disease (CKD) have an increased risk for death from cardiovascular disease (CVD). They have multiple metabolic abnormalities that may accelerate atherosclerosis, such as hypertension, insulin resistance, and dyslipidemia, along with other CKD-related risk factors. In addition, a considerable proportion of patients with advanced stages of CKD are malnourished, presenting "metabolic syndrome with malnutrition". The presence of malnutrition/inflammation dramatically changes the apparent relationship between CVD death risk and some risk factors. For example, in stage 5 CKD patients on hemodialysis, a higher body mass index and a higher plasma cholesterol are predictors of better survival. To understand the paradoxic epidemiology, we should recognize risk factors for occurrence of CVD events and risk factors of fatality after an event. In this article, we review the unique situation of CKD, emphasizing the need of more strict control of both types of risk factors to improve survival of CKD patients.

Preventing cardiovascular outcome in patients with renal impairment: is there a role for lipid-lowering therapy?

Patients with chronic kidney disease (CKD), ranging from modest renal impairment to dialysis and transplant, have an increased risk for cardiovascular disease (CVD). Patients with CKD have both traditional and non-traditional risk factors for CVD. The role of lipids as risk factors for CVD in these populations has not been firmly established. In a recent prospective controlled trial, it was established that atherogenic lipids are indeed strong risk factors for CVD in renal transplant recipients, and that treatment with a HMG-CoA reductase inhibitor reduced the incidence of cardiac death and myocardial infarction. For patients receiving dialysis, the association between serum lipid levels and cardiovascular outcome is uncertain and there is no evidence from controlled trials that lipid-lowering therapy does have a beneficial effect on cardiovascular outcome in these patients. Atherogenic lipids are probably a risk factor for patients with mild or moderate CKD, and five subgroup analyses have indicated a favorable effect of lipid-lowering therapy on cardiovascular outcome, although we still lack prospective controlled trials in these patients. CVD in patients with CKD has been a neglected area of research.