Why do we need a statin trial in hemodialysis patients?

Dialysis Membranes Influence Perfluorochemical Concentrations and Liver Function in Patients on Hemodialysis

Introduction: Perfluoro-octanesulfonate (PFOS) and perfluoro-octanoic acid (PFOA) are two toxic perfluorochemicals (PFCs) commonly used as surfactants. PFCs are difficult to be eliminated from the body. We investigated the influence of different dialysis membranes on the concentrations of PFCs in patients under hemodialysis. Method: We enrolled 98 patients. Of these, 58 patients used hydrophobic polysulfone (PS) dialysis membranes, and the other 40 had hydrophilic membranes made by poly-methyl methacrylate (PMMA) or cellulose triacetate (CTA). Liquid chromatography tandem mass spectrometry coupled was used with isotope dilution to quantify PFOA and PFOS. Results: The predialysis concentrations of PFOA and PFOS in patients with hydrophobic PS dialysis membranes were 0.50 and 15.77 ng/mL, respectively, lower than the concentrations of 0.81 and 22.70 ng/mL, respectively, in those who used hydrophilic membranes (such as CTA or PMMA). Older patients have higher PFOS and poorer body function, with lower Karnofsky Performance Status Scale (KPSS) scores. The demographic data of the two groups were similar. However, patients with hydrophobic PS dialysis membranes had lower predialysis aspartate transaminase (AST) (p = 0.036), lower glucose levels (p = 0.017), and better body function (nonsignificantly higher KPSS scores, p = 0.091) compared with patients who used other membranes. These differences may be associated with the effects of different membranes, because PFOA positively correlated with AST, while PFOS negatively correlated with body function. Conclusions: This is the first study comparing PFC levels in uremic patients with different dialysis membrane. PS membrane may provide better clearance of PFCs and may, therefore, be beneficial for patients.

Coronary risk assessment and management options in chronic kidney disease patients prior to kidney transplantation

Cardiovascular disease remains the most important cause of morbidity and mortality among kidney transplant recipients. Nearly half the deaths in transplanted patients are attributed to cardiac causes and almost 5% of these deaths occur within the first year after transplantation. The ideal strategies to screen for coronary artery disease (CAD) in chronic kidney disease patients who are evaluated for kidney transplantation (KT) remain controversial. The American Society of Transplantation recommends that patients with diabetes, prior history of ischemic heart disease or an abnormal ECG, or age ≥50 years should be considered as high-risk for CAD and referred for a cardiac stress test and only those with a positive stress test, for coronary angiography. Despite these recommendations, vast variations exist in the way these patients are screened for CAD at different transplant centers. The sensitivity and specificity of noninvasive cardiac tests in CKD patients is much lower than that in the general population. This has prompted the use of direct diagnostic cardiac catheterization in high-risk patients in several transplant centers despite the risks associated with this invasive procedure. No large randomized controlled trials exist to date that address these issues. In this article, we review the existing literature with regards to the available data on cardiovascular risk screening and management options in CKD patients presenting for kidney transplantation and outline a strategy for approach to these patients.

HMG CoA reductase inhibitors and renoprotection: the weight of the evidence

Dyslipidemia and the contributions of oxidized low-density lipoproteins (ox-LDL) are independent cardiovascular risk factors. There is growing evidence that dyslipidemia contributes not only to cardiovascular disease but also to the progressive decline of renal function in diabetic and non-diabetic kidney disease. Ox-LDL, by generating inflammation and oxidative stress, contributes to a pro-atherogenic mileu and leads to endothelial dysfunction, subsequent glomerular filtration barrier damage, and progressive renal injury. Chronic kidney disease (CKD), in turn, induces deleterious effects on lipid metabolism. Therefore, by inhibiting cholesterol synthesis and reducing ox-LDL, HMG CoA reductase inhibitors (statins) are attractive therapeutic options to preserve renal function. Current evidence demonstrates a reduction in cardiovascular risk and improved renal outcomes especially in patients with mild to moderate impairment of renal function. Evidence supports a beneficial role of statins thought to extend beyond their lipid-lowering effect, referred to as pleiotropic actions. These actions include modulatory effects on inflammation, oxidative stress and thrombosis, derived from their ability to prevent the formation of isoprenoid intermediates involved in cellular signaling, posttranslational modification of proteins and cellular function. This translates to potential reductions in the rate of decline in GFR in CKD and adverse effects of type 2 diabetes mellitus in the kidney. This review examines the role of statins for reno-protection as well as cardiovascular benefit in patients with CKD.

Managing dyslipidemia in chronic kidney disease

The incidence of chronic kidney disease (CKD) in the U.S. continues to increase, and now over 10% of the U.S. population has some form of CKD. Although some patients with CKD will ultimately develop renal failure, most patients with CKD will die of cardiovascular disease before dialysis becomes necessary. Patients with CKD have major proatherogenic lipid abnormalities that are treatable with readily available therapies. The severe derangements seen in lipoprotein metabolism in patients with CKD typically results in high triglycerides and low high-density lipoprotein (HDL) cholesterol. Because of the prevalence of triglyceride disorders in patients with CKD, after treating patients to a low-density lipoprotein goal, non-HDL should be calculated and used as the secondary goal of treatment. A review of the evidence from subgroup analysis of several landmark lipid-lowering trials supports treating dyslipidemia in mild to moderate CKD patients with HMG-CoA reductase inhibitors. The evidence to support treating dyslipidemia in hemodialysis patients, however, has been mixed, with several outcome trials pending. Patients with CKD frequently have mixed dyslipidemia and often require treatment with multiple lipid-lowering drugs. Although statins are the cornerstone of therapy for most patients with CKD, differences in their pharmacokinetic properties give some statins a safety advantage in patients with advanced CKD. Although most other lipid-lowering agents can be used safely with statins in combination therapy in patients with CKD, the fibrates are renally metabolized and require both adjustments in dose and very careful monitoring due to the increased risk of rhabdomyolysis. After reviewing the safety and dose alterations required in managing dyslipidemia in patients with CKD, a practical treatment algorithm is proposed.

Novel targets and new potential: developments in the treatment of inflammation in chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) of all stages experience extremely high mortality, with cardiovascular causes accounting for about half of all their deaths. Traditional risk factors such as hypertension, hypercholesterolemia and diabetes mellitus cannot explain the excessively high cardiovascular mortality in CKD. Chronic inflammation is one of the novel risk factors that appear to contribute to the increased mortality seen in patients with CKD. Therapeutic interventions targeting chronic inflammation in CKD may lead to improved outcomes.

OBJECTIVES

To describe the role of inflammation in CKD and to review anti-inflammatory pharmacologic therapies that could have a role in its therapy.

METHODS

A review of the literature was carried out and expert opinion expressed.

RESULTS/CONCLUSION

Inflammation is a common and significant problem in CKD. There are currently no approved pharmacologic anti-inflammatory therapies in CKD but several agents are being studied in early clinical trials, while others could become viable alternatives in the future.

Effects of statins in patients with chronic kidney disease: meta-analysis and meta-regression of randomised controlled trials

OBJECTIVE

To analyse the benefits and harms of statins in patients with chronic kidney disease (pre-dialysis, dialysis, and transplant populations).

DESIGN

Meta-analysis.

DATA SOURCES

Cochrane Central Register of Controlled Trials, Medline, Embase, and Renal Health Library (July 2006).

STUDY SELECTION

Randomised and quasi-randomised controlled trials of statins compared with placebo or other statins in chronic kidney disease.

DATA EXTRACTION AND ANALYSIS

Two reviewers independently assessed trials for inclusion, extracted data, and assessed trial quality. Differences were resolved by consensus. Treatment effects were summarised as relative risks or weighted mean differences with 95% confidence intervals by using a random effects model.

RESULTS

Fifty trials (30 144 patients) were included. Compared with placebo, statins significantly reduced total cholesterol (42 studies, 6390 patients; weighted mean difference -42.28 mg/dl (1.10 mmol/l), 95% confidence interval -47.25 to -37.32), low density lipoprotein cholesterol (39 studies, 6216 patients; -43.12 mg/dl (1.12 mmol/l), -47.85 to -38.40), and proteinuria (g/24 hours) (6 trials, 311 patients; -0.73 g/24 hour, -0.95 to -0.52) but did not improve glomerular filtration rate (11 studies, 548 patients; 1.48 ml/min (0.02 ml/s), -2.32 to 5.28). Fatal cardiovascular events (43 studies, 23 266 patients; relative risk 0.81, 0.73 to 0.90) and non-fatal cardiovascular events (8 studies, 22 863 patients; 0.78, 0.73 to 0.84) were reduced with statins, but statins had no significant effect on all cause mortality (44 studies, 23 665 patients; 0.92, 0.82 to 1.03). Meta-regression analysis showed that treatment effects did not vary significantly with stage of chronic kidney disease. The side effect profile of statins was similar to that of placebo. Most of the available studies were small and of suboptimal quality; mortality data were provided by a few large trials only.

CONCLUSION

Statins significantly reduce lipid concentrations and cardiovascular end points in patients with chronic kidney disease, irrespective of stage of disease, but no benefit on all cause mortality or the role of statins in primary prevention has been established. Reno-protective effects of statins are uncertain because of relatively sparse data and possible outcomes reporting bias.

Reverse epidemiology in patients with chronic kidney disease who are not yet on dialysis

Many traditional risk factors show a seemingly paradoxical, inverse association with mortality in patients on dialysis. In spite of their larger numbers, patients with chronic kidney disease (CKD) who are not yet on dialysis are less well studied. Preliminary studies indicate that "reverse epidemiology" is also present in patients with CKD who are not yet on dialysis. Studying patients with CKD offers hope to further our understanding of this phenomenon.

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.

How to Decrease Cardiovascular Mortality in Renal Transplant Recipients

Cardiovascular disease is the leading cause of death following renal transplantation, accounting for 40% to 55% of all deaths. An analysis in our center showed a 15% mortality in a cohort of renal transplant recipients followed for an average of 10 years. Various contributing risk factors of cardiovascular diseases in transplant recipients such as tobacco use, hypertension, hyperlipidemia, hereditary risk, diabetes, physical inactivity, obesity, dialysis duration, hyperuricemia, proteinuria, hyperhomocysteinemia, hyperparathyroidism, anemia; C-reactive protein level, and immunosuppressive regimen as well as some rare risk factors, such as cytomegalovirus infection, were evaluated in a population of 1200 kidney transplant recipients. Also we introduced methods for early detection, monitoring, and follow-up of proven risk factors of cardiovascular disease.

Redefinition of uremic cardiomyopathy by contrast-enhanced cardiac magnetic resonance imaging

Patients with end stage renal failure (ESRF) have an increased risk of premature cardiovascular disease. Left ventricular (LV) abnormalities, so called 'uremic cardiomyopathy', are associated with poorer outcome. Cardiac magnetic resonance imaging (CMR) accurately defines LV dimensions and identifies underlying myocardial pathology. We studied the relationship between LV function and myocardial pathology in ESRF patients with CMR. A total of 134 patients with ESRF underwent CMR. LV function was assessed with further images acquired after gadolinium-diethylentriaminepentaacetic acid (DTPA). The presence of myocardial fibrosis was indicated by late gadolinium enhancement (LGE). Two main myocardial pathologies were identified. A total of 19 patients (14.2%) displayed 'subendocardial LGE' representing myocardial infarction, which was associated with conventional cardiovascular risk factors including a history of ischemic heart disease (IHD) (P < 0.001), hypercholesterolemia (P < 0.05), and diabetes (P < 0.01). Patients with subendocardial LGE had greater LV mass (P < 0.05), LV dilation (P < 0.01), and LV systolic dysfunction (P < 0.001) compared to patients with no evidence of LGE. The second pattern, 'diffuse LGE', seen in 19 patients (14.2%) appeared to represent regional areas of diffuse myocardial fibrosis. Diffuse LGE was associated with greater LV mass compared to patients without LGE (P < 0.01) but not systolic dysfunction. In total, 28.4% of all patients exhibited evidence of myocardial fibrosis demonstrated by LGE. In contrast to published literature describing three forms of uremic cardiomyopathy - left ventricular hypertrophy (LVH), dilation, and systolic dysfunction, we have shown that LVH is the predominant cardiomyopathy specific to uremia, while LV dilation and systolic dysfunction are due to underlying (possibly silent) ischemic heart disease.

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.

Endocrinology and Dialysis: Management of Lipid Abnormalities Associated with End-Stage Renal Disease

The management of lipid abnormalities in patients with end-stage renal disease (ESRD) remains controversial. Large, well-designed studies investigating the effects of dyslipidemia on cardiovascular (CV) morbidity and mortality and the role of cholesterol lowering drugs in reducing mortality in ESRD patients are lacking. While it seems reasonable to suspect that dyslipidemia and its treatment in ESRD patients will affect CV morbidity and mortality similar to that in the general population, recent studies have suggested that this may not be the case. Furthermore, the pharmacokinetics of lipid lowering drugs are altered in patients with ESRD and must be considered when treating this group of patients. This article reviews the major classes of drugs used to treat dyslipidemia, emphasizing their role in patients with ESRD.

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.

Statin therapy in patients with chronic kidney disease: to use or not to use

Dyslipdemia is a common complication of chronic kidney disease (CKD) and contributes to high cardiovascular morbidity and mortality of CKD patients. Experimental studies have demonstrated that lipids induce glomerular and tubulointerstitial injury and that lipid-lowering treatments ameliorate renal injury. Therapy with statins not only has the potential to lower cardiovascular morbidity and mortality in patients with CKD but also to slow progression of renal disease. Whereas the guidelines for treatment of hyperlipidaemia in nonrenal patients are based on prospective, randomized, placebo-controlled mega-trials, such data are not available for CKD patients. This review outlines the limited information currently available on the effect of statins among patients with CKD and summarizes the ongoing randomized trials designed to address this question.

Drug Insight: immunomodulatory effects of statins—potential benefits for renal patients?

Statins inhibit 3-hydroxyl-3-methylglutaryl coenzyme A reductase, an enzyme crucial to cholesterol synthesis. Drugs of this class reduce the risk of coronary heart disease and stroke, in large part through lipid modulation. Emerging evidence indicates that statins have additional modes of action. These actions, which encompass modification of endothelial function, plaque stability, thrombus formation and inflammatory pathways, are widely referred to as 'pleiotropic effects'. These pleiotropic effects indicate that the therapeutic potential of statins might extend beyond cholesterol lowering and cardiovascular disease to other inflammatory disorders or conditions such as transplantation, multiple sclerosis, rheumatoid arthritis and chronic kidney disease. Experimental and clinical data provide evidence to support these broader applications of statins; however, more large-scale trials are needed to clarify the therapeutic benefit.

An assessment of statin safety by nephrologists

Recently, concerns regarding potential adverse effects of the statins on the kidney have been raised. The Kidney Expert Panel of the National Lipid Association's (NLA) Safety Task Force, made up of 3 nephrologists, was convened to review all of the currently available evidence pertinent to determining whether statins cause kidney injury, independent of the known, rare mechanisms of rhabdomyolysis and allergic, drug-induced, interstitial nephritis. The Panel reviewed published and unpublished evidence and found none that suggested that statins, when used in doses currently approved by the US Food and Drug Administration (FDA), cause kidney injury.

Effects of statins on renal function

This report reviews data on the development of proteinuria in patients with chronic kidney disease who are treated with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) for dyslipidemia. Although subgroup analyses of statin trials have shown cardiovascular benefits in subjects with chronic kidney disease, concern about statin-induced proteinuria remains high. Experimental studies have suggested that the proteinuria seen with statin treatment results from the inhibition of receptor-mediated endocytosis, the likely mechanism of protein uptake in proximal tubular cells. Transient proteinuria may signify little more than the effective inhibition of cholesterol synthesis at this site. The blockade of protein trafficking in tubular cells is thought to reduce inflammation, slow fibrosis, and diminish proteinuria in the long term. Post hoc analyses of large clinical trials in subjects without overt renal disease have generally supported this notion, showing that statins most benefit patients with the greatest baseline renal deficits. Statins have also been shown to preserve glomerular filtration rate and reduce proteinuria in subjects with nondiabetic renal disease. In conclusion, in the absence of prospective, randomized trials in renally impaired patients, the collective evidence indicates that statin therapy may slow the decrease in renal function that generally attends atherosclerotic disease. The incidence of proteinuria with potent statins is only 1% to 2% when these drugs are given in recommended doses. Several large trials are currently under way to examine the safety and efficacy of statins in renally compromised patients at high risk for cardiovascular disease.

Prognostic Associations Between Lipid Markers and Outcomes in Kidney Transplant Recipients

BACKGROUND

Hyperlipidemia is highly prevalent in kidney transplant recipients, but the prognostic significance for mortality and allograft survival in these patients has not been established sufficiently.

METHODS

We prospectively enrolled 733 kidney transplant recipients between 1996 and 1998. Clinical information was collected and blood was drawn for laboratory evaluation. Information on the previous transplantation procedures and organ donor were obtained from the Eurotransplant Foundation database. We used the Austrian Dialysis and Transplantation Registry for follow-up. Using multivariate proportional hazard regression, independent relations of fasting plasma triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels to risk for death from any cause and risk for kidney allograft loss were examined.

RESULTS

During a median follow-up of 6.1 years, 154 patients died and 260 kidney allografts were lost. After careful multivariate adjustment, there were no significant associations between TG and TC levels and patient mortality. Patients in the highest quartile of TG and TC levels had no difference in risks for mortality compared with patients in the lowest quartile of these parameters (hazards ratio, 0.81; 95% confidence interval, 0.51 to 1.28; hazards ratio, 0.68; 95% confidence interval, 0.42 to 1.10, respectively). Similarly, no associations were found with allograft loss. Further analysis of associations between high-density lipoprotein cholesterol or low-density lipoprotein cholesterol categories and patient mortality or kidney allograft loss did not show associations.

CONCLUSION

Elevated levels of TC or its subfractions and elevated TG levels are not associated with increased risk for patient mortality or allograft loss in these kidney transplant recipients.

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.

Considerations in the treatment of dyslipidemia associated with chronic kidney failure and renal transplantation

In comparison to the general population, individuals with chronic kidney failure experience an increased risk for atherosclerotic cardiovascular disease attributed predominantly to pronounced abnormalities in lipid metabolism. The emerging consensus is that patients with chronic kidney failure should be treated aggressively for dyslipidemia. Statins reduce the risk of cardiovascular disease in a range of at-risk patients; this class of lipid-lowering drugs should be considered first-line treatment of dyslipidemia observed in renal disease patients. Although the statins share a common lipid-lowering effect, there are differences within this class of drugs. The statins differ in their pharmacokinetic effects, drug interaction profiles, and risk of myotoxicity. This article characterizes the dyslipidemia observed in the renal failure setting and reviews the therapeutic considerations involved in selecting among the statins. Lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, and rosuvastatin are the available statins in the United States.

The evolution of European guidelines: changing the management of cholesterol levels

Cardiovascular disease (CVD) is the leading cause of death in Europe and the US. This paper reviews the evolution of the Joint European Societies' guidelines with respect to their lipid recommendations. We stress the importance of lowering lipid levels to, or below, the currently recommended goals and argue that patients' global risk for CVD, rather than baseline lipid levels, should direct the intensity of lipid-lowering treatment. However, the emphasis on near-term (i.e., in the next 10 years) global risk estimation may under-emphasize the importance of considering lifetime cardiovascular risk in treatment decisions. Although various guidelines' thresholds for treatment initiation and recommended goals differ, they are similar in the theme of treating global risk. Most clinical trials have not identified a threshold of cholesterol level beyond which lowering cholesterol levels no longer provides cardiovascular benefit. An urgent call for action is needed to improve goal attainment in patients with or at risk for CVD. Improving access to risk-reducing treatments should be a priority.

Pleiotropic effects of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors on renal function

Pleiotropic, or non-lipid-dependent, effects mediated by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have important clinical implications for the cardiovascular (CV) system. Atherosclerosis is an inflammatory process accompanied by increases in levels of plasma inflammatory markers and accumulation of immune cells within atherosclerotic plaques. Statins not only decrease serum lipid levels, but also inhibit signaling molecules at several points in inflammatory pathways. The anti-inflammatory effects and improved endothelial function associated with statin therapy are thought to be partly responsible for the reduction in CV morbidity and mortality. In analogy, patients with chronic kidney disease administered statins for CV risk reduction show evidence of improved renal function. However, whether statins confer similar protective benefits on the kidney has not been established. Several lines of evidence suggest that similar etiologic and pathological processes may be involved in CV and chronic kidney diseases. If inflammation and functional changes in the renovascular endothelium contribute to the progression of kidney disease, statins are likely to be effective in the treatment of renal disease. In this review, we critically consider emerging data indicating that statins may modulate renal function by altering the inflammatory response of the kidney and renal vasculature to dyslipidemia. Whether the amelioration of renal function by statins is separable from the lipid-lowering effects of these drugs still remains to be delineated. Other questions that remain to be addressed and issues that should be investigated also are presented.

The role of statins in chronic kidney disease

Chronic kidney disease is associated with cardiovascular event rates that are at least as high as in patients with established atherosclerotic cardiovascular disease or in those with diabetes mellitus. Chronic kidney disease is therefore considered a cardiovascular disease risk equivalent. Treatment of dyslipidemia, which is very common in this population and reflects the pattern seen in the metabolic syndrome, reduces cardiovascular events in patients with chronic kidney disease. Thus, patients with chronic kidney disease should be evaluated and treated for dyslipidemia. Dyslipidemia is a risk factor for the development of impaired kidney function. Dyslipidemia is also associated with progressive renal disease in subjects with no overt renal disease, as well as those with diabetic and nondiabetic kidney disease. Although definitive randomized controlled trials are lacking, the collective evidence suggests that treatment of dyslipidemia is associated with less decline in renal function. The use of potent statins in high doses can lead to transient proteinuria via impairment of proximal tubular receptor--mediated endocytosis, in a dose-dependent manner. Over the long term, however, the use of statins results in a reduction in proteinuria and in the rate of decline of renal function. Several large definitive trials that are currently underway to examine the safety and efficacy of statins in cardiovascular and renal protection should provide more definitive answers on the role of these drugs in this very high risk population.

Are 3-Hydroxy-3-Methylglutaryl-CoA Reductase Inhibitors Renoprotective?: Table 1

Statins reduce serum cholesterol and cardiovascular morbidity and mortality. The mechanisms for these beneficial effects are reviewed. Altered inflammatory responses and improved endothelial function mediated by statins are thought to be partly responsible for the reduction of morbidity and mortality as a result of cardiovascular events. In analogy, whether statins confer similar benefits on the kidney has not been established. This review critically considers the available data whereby dyslipidemia mediates renal dysfunction by modulating the inflammatory response to diverse cytokines. Also reviewed is the emerging database indicating that statins may modulate renal function by altering the response of the kidney to dyslipidemia.

Traditional and nontraditional cardiovascular risk factors in chronic kidney disease

Chronic kidney disease (CKD) is public health problem, with as many as 20 million individuals affected in the United States. Patients with CKD should be considered in the highest-risk group for development of cardiovascular disease (CVD), and aggressive treatment of traditional and nontraditional risk factors should be instituted. Additional randomized controlled trials are urgently needed to evaluate potential treatments in this population. This article focuses attention on the major modifiable cardiovascular risk factors in CKD.

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.

HMG-coenzyme a reductase inhibitor use is associated with mortality reduction in hemodialysis patients

BACKGROUND

Cardiovascular disease is the most common cause of mortality in patients with end-stage renal disease. Cardiovascular benefits of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been clearly established in the general population, but not in dialysis patients. This study examined statin prescription patterns and assessed the relationship between statin prescription and clinical outcomes in hemodialysis (HD) patients.

METHODS

Data were analyzed from the Dialysis Outcomes and Practice Patterns Study, a prospective observational study of HD patients randomly selected from representative dialysis facilities in France, Germany, Italy, Spain, the United Kingdom, Japan, and the United States. Predictors of statin prescription were investigated by means of logistic regression. Cox regression models tested the association between statin prescription and risk for mortality and cardiac events, with adjustments for common demographic factors and comorbid conditions.

RESULTS

Statins were prescribed for 11.8% of HD patients overall. Most facilities (81.2%) prescribed statins to less than 20% of their patients. Patients prescribed statins had a 31% lower relative risk for death compared with those not prescribed statins (P < 0.0001). Statins were associated with a 23% lower cardiac mortality risk (P = 0.03) and a 44% lower noncardiac mortality risk (P < 0.0001). At a facility level, prescribing statins was associated with lower overall mortality rate, with a 5% lower risk for every 10% increase in number of patients prescribed statins within the facility (P = 0.02).

CONCLUSION

Statin prescription is associated with reduced mortality in HD patients, providing additional support for the value of statin therapy in this patient group.

Managing dyslipidemia in chronic kidney disease

OBJECTIVE

Patients with chronic kidney disease (CKD) are at higher risk for cardiovascular disease (CVD) than patients in the general population. One potentially modifiable risk factor for CVD in patients with CKD is dyslipidemia. In the current manuscript we review observational and trial data assessing dyslipidemia and its treatment in this patient population.

RESULTS

Observational studies have noted a "reverse epidemiology" in patients with CKD such that low total cholesterol levels are associated with a higher mortality rate. The complex lipid profile of patients with CKD also raises questions as to whether lipid-lowering therapy will be beneficial in this patient population. Although there are only a few trials assessing the relationship between lipid-lowering therapy and CVD outcomes in CKD patients, many lipid-lowering medications are both safe and effective. In addition, there is suggestive evidence that statin therapy, in particular, also may reduce inflammation and slow the decline in glomerular filtration rate (GFR) in patients during the earlier stages of CKD.

CONCLUSION

Because of the high rate of CVD in patients with CKD and the overall safety of most medical therapies for dyslipidemia in CKD, current guidelines from the National Kidney Foundation Kidney Disease Outcomes Quality Initiative recommend aggressive therapy of dyslipidemia. These guidelines do, however, acknowledge the paucity of trial data in this patient population. There are 3 ongoing randomized controlled trials that are assessing the effect of statin therapy on CVD outcomes. These studies will hopefully provide definitive answers as to the appropriate treatment of dyslipidemia in CKD.

Intérêt des statines en néphrologie

STATINS IN THE CASE OF CHRONIC RENAL DISEASE: Data of several large clinical trials in the general population demonstrated that hydroxymethyl glutaryl coenzyme A reductase inhibitors (statins) are effective in cardiovascular disease prevention with a relatively safe profile. Patients with chronic kidney disease (CKD) are at high risk for developing premature cardiovascular disease, so the benefits of statin therapy might be expected to be substantial in this population. Adjusted dose of statins to calcinurine inhibitors and renal function seem to exhibit a favorable risk/benefit ratio in CKD patients.

STUDY RESULTS

Statin use is CKD patients has been associated with a certain efficacy of cardiovascular disease prevention in several uncontrolled trials, and one randomized trial in renal transplant recipients. Several other large-scale randomized trials in CKD patients [4D (atorvastatin), AURORA (rosuvastatin) and SHARP (simvastatin/ezetimib) are currently underway. The results of these trials will permit evidence-based medicinal arguments justifying life-long clinical use of statins for cardiovascular prevention in CKD patients with progressive renal dysfunction, but data are inconclusive.

OTHER POSSIBLE EFFECTS

Clinically relevant plethoric effects associated with statin therapy in CKD patients might be restricted to the decrease of inflammation and oxidative stress.

Inadequate Treatment of Cardiovascular Disease and Cardiovascular Disease Risk Factors in Dialysis Patients: A Commentary

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in patients with end-stage renal disease (ESRD). Despite its significant impact on health outcomes, which would imply a need for aggressive intervention, both CVD and CVD risk factors are inadequately treated in this patient population. The reasons for this inadequate treatment are unclear. This article reviews the contribution of traditional risk factors to the burden of CVD in ESRD patients, outlines the evidence regarding undertreatment of CVD and traditional CVD risk factors, and identifies potential factors that may be responsible for inadequate cardiovascular care in ESRD patients.