Effects of atorvastatin on triglyceride-rich lipoproteins, low-density lipoprotein subclass, and C-reactive protein in hemodialysis patients

Omega-3 Fatty Acids Reduce Remnant-like Lipoprotein Cholesterol and Improve the Ankle-Brachial Index of Hemodialysis Patients with Dyslipidemia: A Pilot Study

Background and Objectives: Omega-3 fatty acids have potent lipid-lowering and antiplatelet effects; however, randomized controlled trials have yet to examine the effect of high-dose omega-3 fatty acid administration on peripheral artery disease (PAD) in hemodialysis patients with dyslipidemia. Therefore, this study aimed to evaluate the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the ankle-brachial index (ABI) and remnant-like lipoprotein cholesterol (RLP-C) levels, which are indicators of PAD severity. Materials and Methods: Thirty-eight participants (mean age: 73.6 ± 12.7 years) were randomly assigned using stratified block randomization to either conventional therapy alone or conventional therapy supplemented with high-dose EPA/DHA (EPA: 1860 mg; DHA: 1500 mg) for a three-month intervention period. Patients in the conventional therapy alone group who opted to continue were provided with a low-dose EPA/DHA regimen (EPA: 930 mg; DHA: 750 mg) for an additional three months. The baseline and 3-month values for RLP-C, an atherogenic lipid parameter, and the ABI were recorded. Results: The results of the 3-month assessments revealed that the mean RLP-C changes were -3.25 ± 3.15 mg/dL and 0.44 ± 2.53 mg/dL in the EPA/DHA and control groups, respectively (p < 0.001), whereas the changes in the mean ABI values were 0.07 ± 0.11 and -0.02 ± 0.09 in the EPA/DHA and control groups, respectively (p = 0.007). In the EPA/DHA group, a significant negative correlation was found between the changes in RLP-C levels and the ABI (r = -0.475, p = 0.04). Additionally, the change in the RLP-C levels independently influenced the change in the ABI in the EPA/DHA group, even after adjusting for age, sex, and statin use (p = 0.042). Conclusions: Add-on EPA/DHA treatment improved the effectiveness of conventional therapy (such as statin treatment) for improving the ABI in hemodialysis patients with dyslipidemia by lowering RLP-C levels. Therefore, clinicians involved in dialysis should focus on RLP-C when considering residual cardiovascular disease risk in hemodialysis patients and should consider screening patients with elevated levels.

Prospective randomized comparative study of the effect of pemafibrate add-on or double statin dose on small dense low-density lipoprotein-cholesterol in patients with type 2 diabetes and hypertriglyceridemia on statin therapy

AIMS/INTRODUCTION

Small dense low-density lipoprotein (sdLDL) is a more potent atherogenic lipoprotein than LDL. As sdLDL-cholesterol (C) levels are determined by triglyceride and LDL-C levels, pemafibrate and statins can reduce sdLDL-C levels. However, it remains unclear whether adding pemafibrate or increasing statin doses would more effectively reduce sdLDL-C levels in patients receiving statin therapy.

MATERIALS AND METHODS

A total of 97 patients with type 2 diabetes and hypertriglyceridemia who were treated with statins were randomly assigned to the pemafibrate 0.2 mg/day addition or statin dose doubled, and followed for 12 weeks. sdLDL-C was measured by our established homogenous assay.

RESULTS

The percentage and absolute reductions of sdLDL-C levels were significantly greater in the pemafibrate add-on group than the statin doubling group (-32.8 vs -8.1%; -16 vs -3 mg/dL, respectively). Triglyceride levels were reduced only in the pemafibrate add-on group (-44%), and LDL-C levels were reduced only in the statin doubling group (-8%), whereas levels of non-high-density lipoprotein-C and apolipoprotein B were similarly decreased (7-9%) in both groups. The absolute reductions of sdLDL-C levels were closely associated with decreased triglyceride, LDL-C, non-high-density lipoprotein-C and apolipoprotein B. In the subgroup analysis, the effect of pemafibrate add-on on sdLDL-C reductions was observed irrespective of baseline lipid parameters or statin type. No serious adverse effects were observed in both groups.

CONCLUSIONS

In patients with type 2 diabetes and hypertriglyceridemia, the addition of pemafibrate to a statin is superior to doubling a statin in reducing sdLDL-C without increasing adverse effects.

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.

Improvement of endothelial dysfunction is mediated through reduction of remnant lipoprotein after statin therapy in patients with coronary artery disease

BACKGROUND

Remnant lipoproteinemia with high levels of low-density lipoprotein cholesterol (LDL-C) is a high risk for endothelial dysfunction. Statins are the first-line lipid-lowering drugs for this combined hyperlipidemia. However, it remains undetermined whether reduction of remnant lipoprotein mediates the relationship between improvement in endothelial dysfunction and reduction of LDL-C level after statin treatment.

METHODS

A total of 122 coronary artery disease (CAD) patients with impaired flow-mediated dilation (FMD; <5.5%), high levels of LDL-C (≥100 mg/dL), and remnant-like lipoprotein particle cholesterol (RLP-C) (≥5 mg/dL) were examined in this study. The lipid profiles and FMD were measured before and after 6-9 months of statin treatment. The association between changes in LDL-C levels and its relationship with changes in FMD was investigated. Furthermore, mediation analysis was performed to assess the changes in RLP-C level as a mediator of the relationship between the reduction in LDL-C level and improvement of FMD.

RESULTS

Treatment with statins improved FMD in 69 (56.5%) patients. Patients with improved FMD showed lower percent changes of LDL-C, triglyceride (TG), RLP-C, RLP-C/TG, and C-reactive protein (CRP) levels, and higher percent change of HDL-C level, compared to patients who did not show improved FMD. The percent changes in FMD levels had a significant inverse correlation with the percent changes in LDL-C, (r = -0.18, p =  0.03), RLP-C (r = -0.39, p < 0.001), RLP-C/TG (r = -0.34, p < 0.001), and CRP (r = -0.27, p < 0.01). Mediation analysis showed that the relationship between reduction in LDL-C and improvement of FMD was mediated by reduction of RLP-C (34.5%), RLP-C/TG (24.4%), and CRP (24.9%) levels.

CONCLUSION

Improvement of remnant lipoproteinemia may be an important mediator for the relationship between improvement of endothelial dysfunction and LDL-lowering after statin treatment in patients with CAD.

A genetic variant c.553G > T (rs2075291) in the apolipoprotein A5 gene is associated with altered triglycerides levels in coronary artery disease (CAD) patients with lipid lowering drug

Background

Elevated plasma triglycerides (TGs) are widely used as a major cardiovascular risk predictor and are thought to play an important role in the progression of coronary heart disease (CHD). It has been demonstrated that lipid lowering was associated with lower mortality in patients with CHD. The present study therefore aimed to investigate the consequences of the genetic variant c.553G > T (rs2075291) in apolipoprotein A5 gene to determination of triglycerides levels in CAD patients receiving, atorvastatin, lipid lowering drug.

Methods

We here report that a recently identified genetic variant, c.553G > T in the APOA5 gene which causes a substitution of a cysteine for a glycine residue at amino acid residue 185(G185C) is also associated with increased TG levels. To investigate theses effects, a case-control study compressing 608 subjects from the same area was performed.

Results

TG levels in T allele patients were significantly lower than the control GT allele patient (χ² = 2.382E2^a, P-value < 0.001). Overall, patients carrying T allele showed lower levels of TG than patients carrying GG allele. The homozygous patient for the T allele presented normal cholesterol levels of 134 mg/dl, and the levels in GG patients ranged from 25 to 340 mg/dl (P-value < 0.001). In summary, we demonstrated that the presence of c.553G > T variant (rs2075291); in APOA5 gene increases human plasma TG levels.

Conclusion

Nevertheless, T allele is found to reduce TG levels in CAD patients who are on the cholesterol medication, atorvastatin. Thus, c.553G > T variant can be considered as a significant predicator of hypertriglyceridemia. In addition, it could be used as a hallmark for the diagnosis and prognosis of CAD.

Effects of Atorvastatin on Lp(a) and Lipoprotein Profiles in Hemodialysis Patients

Background:

Dialysis patients have many underlying traditional and nontraditional risk factors that may predispose them to a high prevalence of cardiovascular disease. The effects of statins (eg, atorvastatin) on altering nontraditional lipoprotein measures in dialysis patients have not been extensively investigated.

Objective:

To evaluate the efficacy of atorvastatin compared with a control group in inducing changes in lipoprotein(a) [Lp(a)], apolipoprotein (Apo) A-1, Apo-B, and fibrinogen levels, as well as the conventional lipoprotein profile, in hemodialysis patients over 36 weeks; secondary objectives were to assess changes in C-reactive protein, albumin, and safety measures.

Methods:

Forty-five hemodialysis patients with low-density lipoprotein cholesterol (LDL-C) levels greater than 100 mg/dL were randomized to parallel groups: atorvastatin (n = 19) or no treatment (n = 26). The atorvastatin dose was titrated from 10 mg to achieve an LDL-C goal of 100 mg/dL or less and therapy was continued for 36 weeks. Biochemical and lipoprotein laboratory tests for efficacy outcomes were obtained at baseline, 12 weeks, and 36 weeks.

Results:

The atorvastatin group exhibited clinically significant reductions (mean ± SD) compared with controls in total cholesterol (–21.7 ± 41.7 vs –3.2 ± 40.0 mg/dL, respectively; p = 0.017) and LDL-C (–13.1 ± 32.0 vs –1.1 ± 38.4 mg/dL. respectively; p = 0.056) levels, as well as Lp(a) (–10.6 ± 27 vs 3.5 ± 17.8 mg/dL, respectively; p = 0.046). Statistical analyses included analysis of variance on ranked measures for multivariable modeling and paired t-test to determine changes in efficacy measures between baseline and 36 weeks within groups.

Conclusions:

Atorvastatin was safe and effective in reducing Lp(a), total cholesterol, and LDL-C levels. Given the prevalence of atherosclerosis in hemodialysis patients, therapy aimed at reducing traditional and nontraditional risk factors may be beneficial.

An intradialytic increase in serum interleukin-6 levels is associated with an increased mortality in hemodialysis patients

BACKGROUND

The inflammatory marker interleukin-6 (IL-6) increases early in the inflammatory cascade. The aim of this study was to evaluate whether an increase in serum IL-6 levels during a hemodialysis (HD) session is associated with mortality.

METHODS

57 adult patients treated with HD for more than 1 month were prospectively studied over a 3-year follow-up period. Demographic and clinical data were collected and blood samples were drawn before and after a midweek HD session. Events of death and censoring were recorded.

RESULTS

During the 3-year follow-up, 50.8% of the patients died. In univariate Cox regression analysis, an increase in IL-6 levels during HD was associated with an increased mortality (HR 1.41 per pg/ml; 95% CI 1.06 to 1.88; P = .017). In multivariate Cox models, the only independent predictors of all-cause mortality were: an increase in IL-6 levels during dialysis (HR 1.46 per pg/ml; 95% CI 1.08 to 1.98; P = .014), higher baseline C-reactive protein (CRP) levels and older age. When predictors of an increase in serum IL-6 levels during HD were introduced into the model, mortality was still significantly associated with IL-6 elevation during dialysis (HR 1.47 per pg/ml, 95% CI 1.01 to 2.14; P = .045).

CONCLUSIONS

A rise in serum IL-6 levels during a single HD session is associated with a higher mortality among HD patients, independent of predialysis CRP or IL-6 levels. The results may imply the presence of an intradialytic inflammatory response that affects survival in HD patients.

The Effect of n-3 Fatty Acids on Small Dense Low-Density Lipoproteins in Patients With End-Stage Renal Disease: A Randomized Placebo-Controlled Intervention Study

OBJECTIVE

Patients with end-stage renal disease (ESRD) have a high risk of cardiovascular disease. Small dense low-density lipoprotein (sdLDL) particles are particularly atherogenic. Marine n-3 polyunsaturated fatty acids (PUFA) may have a beneficial effect on numbers of sdLDL particles, and the aim of this study was to investigate the effect of n-3 PUFA on plasma levels of sdLDL in patients with ESRD.

METHODS

ESRD patients with cardiovascular disease (n = 161) on chronic hemodialysis were randomized to treatment with 1.7 g of n-3 PUFA (n = 81) or 2 g of placebo (olive oil; n = 80) for 3 months. The study was double-blinded. Densities of LDL and percentages of sdLDL (sdLDL%) of total LDL were measured before and after intervention. On the basis of sdLDL%, patients were classified as having lipid pattern A, I (intermediate), or B defined by a successive increase in sdLDL concentration and decrease in lipid particle size.

RESULTS

n-3 PUFAs significantly reduced triglycerides. However, LDL cholesterol remained unchanged. In the n-3 group, the LDL density did not change significantly during follow-up. Similarly, the LDL density remained unchanged in the placebo group. In the n-3 group, the sdLDL% was 34% at baseline and unchanged at follow-up. At baseline 71% had LDL pattern A, 9% had pattern I, and 20% had pattern B, and none of these patterns were significantly changed by n-3 PUFA supplementation.

CONCLUSION

Dietary supplementation with 1.7 g of n-3 PUFA had no effect on LDL density or sdLDL levels in patients with ESRD.

Obesity and kidney protection

CONTEXT

Obesity, both directly and indirectly, increases the risk for a variety of disease conditions including diabetes, hypertension, liver disease, and certain cancers, which in turn, decreases the overall lifespan in both men and women. Though the cardiovascular risks of obesity are widely acknowledged, less often identified is the relationship between obesity and renal function.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, PubMed, EBSCO and Web of Science has been searched.

RESULTS

The concept of the "Metabolic Syndrome" helps us to understand this close link between obesity, diabetes, hypertension, and renal dysfunction. An elevated body mass index has shown to be one of the major determinants of glomerular hyperfiltration that lead to the development of chronic kidney disease. Interestingly, weight loss can lead to attenuation of hyperfiltration in severely obese patients suggesting a possible therapeutic option to combat obesity-related hyperfiltration.

CONCLUSIONS

Various treatment strategies had been suggested to decrease impact of obesity on kidneys. These are blood pressure controling, inhibition of the renin-angiotensinaldosterone axis, improving glycemic control, improving dyslipidemia, improving protein uriaand lifestyle modifications. Regardless of the numerous pharmacotherapies, the focus should be on the root cause: obesity.

Erythropoietin; a review on current knowledge and new concepts

Chronic kidney disease (CKD) is a worldwide health problem. However, despite to new routes of dialysis, mortality and morbidity is high. One of the most common symptom of CKD is anemia, especially is more obvious in stages 3 and 4. In this review, we compared the effects of erythropoietin and anemia correction on kidney function (GFR) by investigating in various studies. Despite extensive studies in this category, still we do not sure about the effects of erythropoietin and anemia correction on the glomerular filtration rate.

The differential effects of thiazolidindiones on atherogenic dyslipidemia in type 2 diabetes: what is the clinical significance?

BACKGROUND

Diabetic dyslipidemia is typically characterized by an increase in plasma triglycerides, a decrease in high-density lipoprotein cholesterol and a concomitant increase in atherogenic small dense low-density lipoproteins. Thiazolidindiones are able to lower the levels of fasting glucose and glycated hemoglobin significantly by improving insulin sensitivity, as well as improving some aspects of diabetic dyslipidemia: total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol tend to increase while triglycerides are generally decreased.

OBJECTIVE

This paper reviewed the effects of pioglitazone and rosiglitazone on atherogenic diabetic dyslipidemia, in particular on small dense low-density lipoprotein particles.

METHODS

A literature search (by Medline and Scopus) was performed up to 15 March 2008. The authors also manually reviewed the references of selected articles for any pertinent material.

RESULTS

Pioglitazone showed an additional beneficial effect on triglycerides, high-density lipoprotein cholesterol and the levels of small dense low-density lipoprotein compared to rosiglitazone.

CONCLUSIONS

Since recent studies have suggested that these agents may also have a differential effect on long-term cardiovascular end-points despite similar improvements in glycated hemoglobin and insulin sensitivity, the different impact on atherogenic diabetic dyslipidemia may help to explain these findings.

Effect of pravastatin on markers of endothelial activation in dialysis patients

AIM

The aim of this pilot study was to test the effect of pravastatin on serum levels of high-sensitivity CRP (hs-CRP), IL-6 and the soluble adhesion molecules sVCAM-1, sICAM-1 and sE-selectin in chronic dialysis patients.

METHODS

At the commencement of the study, serum levels of lipids, liver function tests and endothelial markers (CRP, IL-6, sICAM-1, sVCAM-1, sE-selectin) were measured. Patients then commenced 1 month of 10 mg of pravastatin per day, and if tolerated, then 4 months of 40 mg of pravastatin per day. Serum levels of lipids, liver function tests and endothelial markers were repeated after the total of 5 months of pravastatin therapy.

RESULTS

Thirty-nine patients were enrolled, and 25 (male/female 17/8; 21 haemodialysis, 4 peritoneal dialysis) patients completed the study. Pravastatin therapy significantly improved the patients' lipid profiles, but had no significant effect on the levels of CRP, IL-6, sICAM-1, sVCAM-1, or sE-selectin.

CONCLUSION

Short-term (5 months) treatment with pravastatin in patients receiving chronic dialysis improved their lipid profile, but had no significant effect on surrogate markers of endothelial activation.

HMG-CoA reductase inhibitors and the kidney

During the last two decades, numerous studies have demonstrated that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) diminish the risk of cardiovascular morbidity and mortality. Although these studies have focused primarily on the ability of statins to lower circulating levels of low-density lipoprotein cholesterol, more recent research has shown that statins may protect the vasculature via pleiotropic effects not directly related to lipid lowering. These include adjustments in cell-signaling pathways that play a role in atherogenesis and that affect the expression of inflammatory elements, curtail oxidative stress, and enhance endothelial function. More recently, researchers have begun to explore whether these agents exert similar beneficial effects in renal parenchymal and renovascular disease. This review examines the available evidence that dyslipidemia may augment the inflammatory reaction of cytokines in patients with renal disease and that statins may improve renal dysfunction by altering the response of the kidney to dyslipidemia, even in persons with end-stage renal disease on dialysis or with renal transplantation. In this context, some data suggest that statin-mediated alterations in inflammatory responses and endothelial function may reduce proteinuria and the rate of progression of kidney disease.

Effects of statins, fibrates, rosuvastatin, and ezetimibe beyond cholesterol: the modulation of LDL size and subclasses in high-risk patients

Increasing evidence suggests that the quality-rather than just the quantity-of low-density lipoproteins (LDLs) exerts a great influence on cardiovascular risk. LDLs comprise multiple subclasses with discrete size and density, and different physicochemical composition, metabolic behaviors, and atherogenicity. Individuals generally cluster into 2 broad subgroups. Most have a predominance of large LDLs, and some have a higher proportion of small particles. Small, dense LDLs are good predictors of cardiovascular events and progression of coronary artery disease. Their predominance has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III. Several studies have shown that therapeutic modulation of LDL size and subclass is of great benefit in reducing the risk of cardiovascular events. This seems particularly true for statins and fibrates when they are administered to higher-risk patients, such as those with type 2 diabetes or vascular disease. Data reporting outcomes with the use of rosuvastatin, the latest statin molecule introduced to the market, and ezetimibe, a cholesterol absorption inhibitor, are promising.

Statins and cardiovascular risk reduction in patients with chronic kidney disease and end-stage renal failure

BACKGROUND

Although numerous large-scale trials have firmly established the benefits of statins for primary and secondary prevention of coronary artery disease, the role of this class of agents in patients with impaired renal function remains unclear.

METHODS AND RESULTS

In the following review, we evaluate current evidence regarding the role of statins in patients with both chronic kidney disease (CKD) and end-stage renal disease (ESRD) on hemodialysis. Although statins do appear to reduce cardiovascular risk in patients with CKD, it remains unclear whether such benefit extends to the ESRD population. Thus far, 1 randomized placebo-controlled trial failed to demonstrate a statistically significant reduction in the primary endpoint of cardiovascular death, stroke, and nonfatal myocardial infarction among patients with ESRD on hemodialysis. This finding contrasts with observational analyses suggesting improved outcomes among patients with ESRD taking statins.

CONCLUSIONS

Risk factors unique to the CKD population, which may not be modifiable with statins, could contribute to the increased cardiovascular morbidity among patients with ESRD. These include alterations in mineral metabolism, elevation in serum homocysteine, and increased oxidative stress. Larger prospective studies are needed to elucidate the role of statins in patients with chronic kidney disease, including those with ESRD on dialysis. Pending further data, we currently recommend using statins in patients with CKD.

Efficacy, safety and tolerability of atorvastatin in dyslipidemic subjects with advanced (non-nephrotic) and endstage chronic renal failure

BACKGROUND

Patients with dyslipidemia and advanced renal failure are at markedly increased risk of cardiovascular morbidity and mortality. We evaluated the efficacy, safety, and tolerability of atorvastatin in non-nephrotic, dyslipidemic patients with chronic renal failure (CRF) or endstage renal failure (ESRF) receiving dialysis.

METHODS

Following a 6-week baseline period, adult patients meeting Australian Heart Foundation treatment guidelines received atorvastatin for 16 weeks: 19 with CRF (predialysis), 17 on hemodialysis (HD), and 13 on continuous ambulatory peritoneal dialysis (CAPD). Dose (10-40 mg daily) was titrated to achieve lipid-lowering targets. Efficacy was determined by monitoring lipids (principally triglycerides and low-density lipoprotein [LDL] cholesterol); safety and tolerance by monitoring clinical and laboratory parameters.

RESULTS

Atorvastatin was effective in reducing LDL cholesterol from baseline at each of weeks 4, 8, 12, and 16 in all study groups, with reductions of more than 40% at week 16. Sixty-two percent of PD, 73% of HD, and 100% of CRF patients were at or below target (<2.6 mmol/l) for LDL cholesterol at week 16. Significant reductions in triglycerides (approximately 27%) were seen in the CRF and combined HD/CAPD groups at all time points. Depending on the group, 65%-83% of patients were at or below target (<2.0 mmol/l) for triglycerides at week 16. The majority of patients received the 10-mg dose. Atorvastatin also reduced total cholesterol and apolipoprotein B levels in all groups and very-low-density lipoprotein (VLDL) cholesterol in the CRF group. Significant increases in LDL particle size were found in the HD and combined HD/CAPD groups. Minor, particularly gastrointestinal, symptoms were common. Three patients reported musculoskeletal symptoms, but creatine kinase was raised in only one.

CONCLUSION

Atorvastatin is an effective lipid-lowering agent for dyslipidemic subjects with advanced and endstage renal failure, and was reasonably well tolerated.

Cardiovascular Biomarkers in CKD: Pathophysiology and Implications for Clinical Management of Cardiac Disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with all forms of chronic kidney disease (CKD). The underlying pathological state is caused by a complex interplay of traditional and nontraditional risk factors that results in atherosclerosis, arteriosclerosis, and altered cardiac morphological characteristics. This multifactorial disease introduces new challenges in predicting and treating patients with CVD sufficiently early in the course of CKD to positively alter patient outcome. Asymptomatic individuals with progressive CVD are a group of patients that deserve focused attention because early detection and intervention may provide the best opportunity for improved outcome. However, identifying CVD in asymptomatic patients with CKD or end-stage renal disease remains a significant hurdle in the management of these patients. Recently, a number of cardiovascular biomarkers were identified as predictors of patient outcome in individuals with CVD and, with additional research, may be used to guide the early diagnosis of and therapy for CVD in patients with CKD. This review examines the pathophysiological characteristics and potential clinical role of these novel cardiovascular biomarkers in risk stratification, risk monitoring, and selection of preventive therapies for patients with CKD.

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.

The Clinical Relevance of Low-Density-Lipoproteins Size Modulation by Statins

The predominance of small, dense low density lipoproteins (LDL) has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III; in fact, LDL size seems to be an important predictor of cardiovascular events and progression of coronary heart disease. Several studies have also shown that the therapeutical modulation of LDL size is of great benefit in reducing the risk of cardiovascular events. Hypolipidemic treatment is able to alter LDL subclass distribution and statins are currently the most widely used lipid-lowering agents. Statins are potent inhibitors of hydroxy-methyl-glutaryl-coenzyme A reductase, the rate-limiting enzyme in hepatic cholesterol synthesis and are the main drugs of choice for the treatment of elevated plasma LDL cholesterol concentrations. Statins potentially lower all LDL subclasses (e.g., large, medium and small particles); thus, their net effect on LDL subclasses or size is often only moderate. However, a strong variation has been noticed among the different agents: analyses of all published studies suggest a very limited role of pravastatin and simvastatin in modifying LDL size and their subclasses, while fluvastatin and atorvastatin seem to be much more effective agents. Finally, rosuvastatin, the latest statin molecule introduced in the market, seems to be promising in altering LDL subclasses towards less atherogenic particles.

Low-density lipoprotein size and cardiovascular risk assessment

A predominance of small, dense low-density lipoproteins (LDL) has been accepted as an emerging cardiovascular risk factor by the National Cholesterol Education Program Adult Treatment Panel III. LDL size seems to be an important predictor of cardiovascular events and progression of coronary heart disease and evidences suggests that both quality (particularly small, dense LDL) and quantity may increase cardiovascular risk. However, other authors have suggested that LDL size measurement does not add information beyond that obtained by measuring LDL concentration, triglyceride levels and HDL concentrations. Therefore, it remains debatable whether to measure LDL particle size in cardiovascular risk assessment and, if so, in which categories of patient. Therapeutic modulation of LDL particle size or number appears beneficial in reducing the risk of cardiovascular events, but no clear causal relationship has been shown, because of confounding factors, including lipid and non-lipid variables. Studies are needed to investigate the clinical significance of LDL size measurements in patients with coronary and non-coronary forms of atherosclerosis; in particular, to test whether LDL size is associated with even higher vascular risk, and whether LDL size modification may contribute to secondary prevention in such patients.

Phospholipid transfer protein activity is associated with inflammatory markers in patients with cardiovascular disease

Plasma phospholipid lipid transfer protein (PLTP) has several known key functions in lipoprotein metabolism. Recent studies suggest that it also may play a role in the inflammatory response. Inflammatory cell activity contributes to the development of atherosclerosis. To seek further evidence for the association of PLTP with inflammation, we studied the relationship between PLTP activity and five inflammatory markers [C-reactive protein (CRP), serum amyloid A (SAA), interleukin 6 (IL-6), white blood cells (WBC), and fibrinogen] in 93 patients with low HDL and cardiovascular disease (CVD). Plasma PLTP activity had the strongest correlation with CRP (r=0.332, P<0.001) followed by SAA (r=0.239, P=0.021). PLTP, CRP, and SAA were significantly associated with body mass index (BMI), insulin or glucose, apolipoprotein (apo) B, and/or apo E level (r=0.264-0.393, P<0.01). PLTP, SAA, and IL-6 also were associated with the concentration of HDL particles without apo A-II [Lp(A-I)](r=0.373-0.472, P<0.005, n=56), but not particles with apo A-II. Smoking was associated with increased PLTP activity, CRP, and WBC, and hypertension with increased PLTP activity. In linear models, CRP remained significantly associated with PLTP after adjustment of CVD risk factors and insulin resistance. Also, much of the variability of plasma PLTP activity was explained by CRP, BMI, Lp(A-I), smoking, glucose, and blood pressure. These findings show for the first time that plasma PLTP activity is associated positively with CRP in CVD, a state of chronic inflammation.

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.