3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and rhabdomyolysis: considerations in the renal failure patient

HMG CoA reductase inhibitors (statins) for dialysis patients

BACKGROUND

Cardiovascular disease accounts for more than half the number of deaths among dialysis patients. The role of HMG CoA reductase inhibitors (statins) in the treatment of dyslipidaemia in dialysis patients is unclear and their safety has not been established.

OBJECTIVES

To assess the benefits and harms of statins in peritoneal dialysis (PD) and haemodialysis patients (HD).

SEARCH STRATEGY

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled trials (CENTRAL, in The Cochrane Library), the Cochrane Renal Group's specialised register and handsearched reference lists of textbooks, articles and scientific proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing statins with placebo, no treatment or other hypolipidaemic agents in dialysis patients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model after testing for heterogeneity. The results were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

Fourteen studies (2086 patients) compared statins versus placebo or other lipid lowering agents. Compared to placebo, statins did not decrease all-cause mortality (10 studies, 1884 patients; RR 0.95, 95% CI 0.86 to 1.06) or cardiovascular mortality (9 studies, 1839 patients: RR 0.96, 95% CI 0.65 to 1.40). There was a lower incidence of nonfatal cardiovascular events with statins compared to placebo in haemodialysis patients (1 study, 1255 patients; RR 0.86, 95% CI 0.74 to 0.99). Compared with placebo, statin use was associated with a significantly lower end of treatment average total cholesterol (14 studies, 1823 patients; MD -42.61 mg/dL, 95% CI -53.38 to -31.84), LDL cholesterol (13 studies, 1801 patients; MD -43.06 mg/dL, 95% CI -53.78 to -32.35) and triglycerides (14 studies, 1823 patients: MD -24.01 mg/dL, 95% CI -47.29 to -0.72). There was similar occurrence of rhabdomyolysis and elevated liver function tests with statins in comparison to placebo.

AUTHORS' CONCLUSIONS

Statins decreased cholesterol levels in dialysis patients similar to that of the general population. With the exception of one study, studies were of short duration and therefore the efficacy of statins in decreasing the mortality rate is still unclear. Statins appear to be safe in this high-risk population. Ongoing studies should provide more insight about the efficacy of statins in reducing mortality rates in dialysis patients.

HMG CoA reductase inhibitors (statins) for dialysis patients

BACKGROUND

Cardiovascular disease accounts for more than half the number of deaths among dialysis patients. The role of HMG CoA reductase inhibitors (statins) in the treatment of dyslipidaemia in dialysis patients is unclear and their safety has not been established.

OBJECTIVES

To assess the benefits and harms of statins in peritoneal dialysis (PD) and haemodialysis patients (HD).

SEARCH STRATEGY

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled trials (CENTRAL, in The Cochrane Library), the Cochrane Renal Group's specialised register and handsearched reference lists of textbooks, articles and scientific proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing statins with placebo, no treatment or other hypolipidaemic agents in dialysis patients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model after testing for heterogeneity. The results were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

Fourteen studies (2086 patients) compared statins versus placebo or other lipid lowering agents. Compared to placebo, statins did not decrease all-cause mortality (10 studies, 1884 patients; RR 0.95, 95% CI 0.86 to 1.06) or cardiovascular mortality (9 studies, 1839 patients: RR 0.96, 95% CI 0.65 to 1.40). There was a lower incidence of nonfatal cardiovascular events with statins compared to placebo in haemodialysis patients (1 study, 1255 patients; RR 0.86, 95% CI 0.74 to 0.99). Compared with placebo, statin use was associated with a significantly lower end of treatment average total cholesterol (14 studies, 1823 patients; MD -42.61 mg/dL, 95% CI -53.38 to -31.84), LDL cholesterol (13 studies, 1801 patients; MD -43.06 mg/dL, 95% CI -53.78 to -32.35) and triglycerides (14 studies, 1823 patients: MD -24.01 mg/dL, 95% CI -47.29 to -0.72). There was similar occurrence of rhabdomyolysis and elevated liver function tests with statins in comparison to placebo.

AUTHORS' CONCLUSIONS

Statins decreased cholesterol levels in dialysis patients similar to that of the general population. With the exception of one study, studies were of short duration and therefore the efficacy of statins in decreasing the mortality rate is still unclear. Statins appear to be safe in this high-risk population. Ongoing studies should provide more insight about the efficacy of statins in reducing mortality rates in dialysis patients.

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Dyslipidaemia occurs frequently in chronic kidney disease (CKD) patients and contributes both to cardiovascular disease and worsening renal function. Statins are widely used in non-dialysis dependent CKD patients (pre-dialysis) even though evidence favouring their use is lacking.

OBJECTIVES

To evaluate the benefits and harms of statins in CKD patients who were not receiving renal replacement therapy.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, CENTRAL (in The Cochrane Library), and hand-searched reference lists of textbooks, articles and scientific proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing statins with placebo, no treatment or other statins in adult pre-dialysis CKD patients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Results were expressed as mean difference (MD) for continuous outcomes (lipids, creatinine clearance and proteinuria) and risk ratio (RR) for dichotomous outcomes (all-cause mortality, cardiovascular mortality, fatal and non-fatal cardiovascular events, elevated liver enzymes, rhabdomyolysis and withdrawal rates) with 95% confidence intervals (CI).

MAIN RESULTS

Twenty six studies (25,017 participants) comparing statins with placebo were identified. Total cholesterol decreased significantly with statins (18 studies, 1677 patients: MD -41.48 mg/dL, 95% CI -49.97 to -33.99). Similarly, LDL cholesterol decreased significantly with statins (16 studies, 1605 patients: MD -42.38 mg/dL, 95% CI -50.71 to -34.05). Statins decreased both the risk of all-cause (21 RCTs, 18,781 patients, RR 0.81, 95% CI 0.74, 0.89) and cardiovascular deaths (20 studies, 18,746 patients: RR 0.80, 95% CI 0.70 to 0.90). Statins decreased 24-hour urinary protein excretion (6 studies, 311 patients: MD -0.73 g/24 h, 95% CI -0.95 to -0.52), but there was no significant improvement in creatinine clearance - a surrogate marker of renal function (11 studies, 548 patients: MD 1.48 mL/min, 95% CI -2.32 to 5.28).The incidence of rhabdomyolysis, elevated liver enzymes and withdrawal rates due to adverse events (well known complications of statins use), were not significantly different between patients receiving statins and placebo.

AUTHORS' CONCLUSIONS

Statins significantly reduced the risk of all-cause and cardiovascular mortality in CKD patients who are not receiving renal replacement therapy. They do not impact on the decline in renal function as measured by creatinine clearance, but may reduce protein excretion in urine. Statins appear to be safe in this population. Guidelines recommendations on hyperlipidaemia management in CKD patients could therefore be followed targeting higher proportions of patients receiving a statin, with appropriate monitoring of adverse events.

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.

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.

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.

Statins: beneficial or adverse for glucose metabolism

Large-scale clinical trials have established that statin use for lowering blood cholesterol is beneficial in reducing atherosclerotic cardiovascular diseases in different populations. However, the general reputation of statins seems to be clouded by a potential adverse effect of a class of statins on glucose metabolism. This paper reviewed clinical data of statins regarding the effects on diabetes mellitus and glucose metabolism. At least five randomized controlled studies, primarily investigating the protective effect of statins on the risk of cardiovascular diseases, have addressed the effect of statins on glucose metabolism in Western countries. One study showed that pravastatin (40 mg/day) was protective against the development of diabetes mellitus. Two studies of atorvastatin (10 mg/day) and one study of simvastatin (40 mg/day) showed no measurable effect of these regimens on the risk of diabetes mellitus or the clinical course of diabetes mellitus. One study of atorvastatin (80 mg/day) versus pravastatin (40 mg/day) suggested a deterioration of glucose metabolism associated with a high dose of atorvastatin. In Japan, a few case reports have noted a potential adverse effect of atorvastatin on glycemic control in patients with diabetes mellitus; however, seven clinical trials have showed no such effect of atorvastatin although these studies were relatively small in size and short in follow-up. Only one of the two observational studies suggested a possible adverse effect of atorvastatin on glycemic control. Evidence is extremely limited regarding atorvastatin use and deterioration in glycemic control, and further studies are needed to draw a conclusion on this issue.

Effects of fluvastatin treatment on lipid profile, C-reactive protein trend, and renal function in dyslipidemic patients with chronic renal failure

The purpose of this trial was to evaluate the effects of fluvastatin on the lipid pro-file and on renal function, as measured by creatinine clearance, in dyslipidemic patients with chronic renal failure. In this 8-month prospective, open-label, randomized, parallel-group trial, 130 patients (70 men and 60 women), after a 2-month washout period following previous lipid-lowering treatments, were randomly assigned to fluvastatin XL 80 mg given once daily (80 patients) or to standard treatment (50 patients). Mean total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride values after 3 and 6 months of treatment with fluvastatin showed statistically significant improvement compared with standard treatment. Improved renal function, as measured by creatinine clearance, was observed at the end of the 6-month treatment period in approximately 65% of patients treated with fluvastatin. The increase in creatinine clearance consistently reached 10% to 15% of baseline values. A statistically significant reduction in C-reactive protein (CRP) over baseline values was observed in approximately 75% of patients treated with fluvastatin. Furthermore, mean values of CRP for the fluvastatin standard treatment groups, respectively, were 6.78 and 10.19 at 3 months and 4.47 and 11 at 6 months. Both treatments were well tolerated. No major adverse events were noted. Results of this study suggest that fluvastatin treatment in patients with chronic renal failure is effective in improving the lipid profile, and it demonstrates good safety and tolerability. Furthermore, fluvastatin may contribute to improved nephroprotection in this patient population.

Changes in ubiquitin proteasome pathway gene expression in skeletal muscle with exercise and statins

OBJECTIVE

Statins are safe medications but have side effects including myalgia and rhabdomyolysis. How statins provoke muscle damage is not known, but this effect is exacerbated by exercise.

METHODS AND RESULTS

Healthy subjects took Atorvastatin (80 mg/daily) or placebo for 4 weeks. Biopsies of both vastus lateralis muscles were performed 8 hours after eccentric exercise (known to result in muscle soreness and damage) of the left leg at baseline and the right leg after statin/placebo treatment. Gene expression was determined using Affymetrix GeneChips, and selected genes confirmed by polymerase chain reaction (qRT-PCR). Atorvastatin had little effect on gene expression at rest. When combined with exercise, 56 genes were differentially expressed with 18% involved in the ubiquitin proteasome pathway (UPP) and 20% involved in protein folding and catabolism, and apoptosis.

CONCLUSIONS

This is the first investigation to our knowledge to implicate involvement of the UPP in skeletal muscle in response to combined exercise and statin treatment, possibly explaining the onset of myalgia with exertion. Statins may alter the response of muscle to exercise stress by altering the action of the UPP, protein folding, and catabolism, disrupting the balance between protein degradation and repair.

The Potential Role of HMG-CoA Reductase Inhibitors in Pediatric Nephrotic Syndrome

OBJECTIVE

To evaluate the safety and efficacy of the hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) as a potential treatment option for the dyslipidemia associated with childhood nephrotic syndrome.

DATA SOURCES

Searches of MEDLINE (1966–April 2004), Cochrane Library, International Pharmaceutical Abstracts (1977–April 2004), and an extensive manual review of journals were performed using the key search terms nephrotic syndrome, familial hypercholesterolemia, dyslipidemia, and HMG-CoA reductase inhibitor.

STUDY SELECTION AND DATA EXTRACTION

Two prospective uncontrolled studies evaluating the safety and efficacy of statin therapy in pediatric nephrotic syndrome were included.

DATA SYNTHESIS

While an extensive amount of data is available in adult nephrotic syndrome in which statin therapy decreases total plasma cholesterol 22–39%, low-density lipoprotein cholesterol (LDL-C) 27–47%, and total plasma triglycerides 13–38%, only 2 small uncontrolled studies have been conducted evaluating the utility of these agents in pediatric nephrotic syndrome. These studies indicate that statins are capable of safely reducing total cholesterol up to 42%, LDL-C up to 46%, and triglyceride levels up to 44%.

CONCLUSIONS

Lowering cholesterol levels during childhood may reduce the risk for atherosclerotic changes and may thus be of benefit in certain patients with nephrotic syndrome. Statins have demonstrated short-term safety and efficacy in the pediatric nephrotic syndrome population. Implementing pharmacologic therapy with statins in children with nephrotic syndrome must be done with care until controlled studies are conducted in this population.

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

Dyslipidemia is an important risk factor for cardiovascular disease in patients with chronic renal failure (CRF). We evaluated the safety and efficacy of atorvastatin in patients with dyslipidemia associated with CRF who were undergoing hemodialysis (HD). Thirty-five patients who were receiving HD were given atorvastatin (10 mg/d) for 3 months. Chylomicron (CM), light and dense very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and light and dense low-density lipoprotein (LDL) were separated by ultracentrifugation. Apolipoprotein (apo) B was measured by electroimmunoassay. Mean LDL particle diameter was measured by gradient gel electrophoresis. Atorvastatin therapy reduced LDL-cholesterol (C) by 36% and remnant-like particle (RLP)-C by 58%. Atorvastatin significantly reduced apo B, apo CIII, and apo E in VLDL by 40% to 46% and IDL-apo B by 66%. Atorvastatin also significantly reduced cholesterol in CM, light VLDL, and dense VLDL without consistently affecting triglyceride (TG) in these lipoproteins. Atorvastatin similarly reduced both light and dense LDL-apo B by 38%. LDL particle size in the HD patients significantly increased during atorvastatin treatment from 25.7 +/- 0.4 to 26.2 +/- 0.6 nm. High sensitive C-reactive protein (HS-CRP) was halved by atorvastatin decreasing from 0.08 +/- 0.05 to 0.04 +/- 0.03 mg/dL. Atorvastatin treatment did not affect the creatinine kinase level, and no classical adverse effects were observed during the study. These results suggest that atorvastatin is safe and effective for the management of dyslipidemia in patients with CFR who are receiving HD, which may help to suppress the development of atherosclerosis.

Slowing the progression of diabetic nephropathy and its cardiovascular consequences

This paper incorporates the findings from a multidisciplinary meeting on diabetic nephropathy and its renal and cardiovascular complications into a review article. The epidemic of obesity and the growing elderly population in the United States are primary drivers of a secondary epidemic of incipient type 2 diabetes mellitus and diabetic nephropathy. Current therapies aim to treat blood pressure, particularly with agents that block the renin-angiotensin system, to a target of 130/80 mm Hg. However, even lower blood pressure targets may be optimal. Control of hyperglycemia and dyslipidemia, smoking cessation, exercise, and weight loss all compliment blood pressure control and are achieved most effectively when the patient, provider, and health system are aligned with these goals. Once end-stage renal disease (ESRD) is reached, patients enter the highest cardiovascular risk-state appreciated in human medicine. Because of uniform access to care in the United States, advanced data systems, and circulatory system (intravascular) access in most patients, the ESRD population should be the future sampling frame for newer treatments tested in both prospective cohort and randomized trials. Cardiorenal risk, or the degree of excess cardiovascular risk incurred by patients with chronic kidney disease and ESRD, is a state offering considerable research opportunities for novel cardiovascular risk factors. Future studies should fully consider the possibility that improved outcomes would be achieved at a greater cost; thus, cost-effectiveness studies are essential for understanding the economic aspects of implementation. The goal of an ideal clinical trial would be ESRD prevention; however, pragmatic objectives such as a greater understanding of therapeutic toxicities should also be explored in this population.

Current overview of statin-induced myopathy

Statins are an efficacious and well-tolerated class of lipid-altering agents that have been shown to reduce the risk of initial and recurrent cardiovascular events. However, cerivastatin was withdrawn from the world market because of its potential for severe myotoxic effects. Since the benefits of statin treatment outweigh the small risk of adverse events, statins remain the first-line therapy for lipid lowering and preventing atherosclerotic cardiovascular diseases. The risk of myopathy may be minimized with the appropriate choice of agent and by identifying patients at risk of myotoxic effects. Elderly or female patients, or those with concomitant medications or impaired metabolic processes, may be at increased risk and should be monitored closely. The risk of myopathy may also be inferred from the pharmacologic and pharmacokinetic properties of the statin used. Since myotoxic events are more frequent at higher doses, statins that are effective in reducing cholesterol levels and helping patients to reach target levels at start doses may be useful. The lipophilicity of a statin and its potential for drug-drug interactions may also help to determine the likelihood of muscular effects. Drug-drug interactions may be avoided by selecting a statin that does not share the same metabolic pathway.

Treatment with Fluvastatin Rapidly Modulates, via Different Pathways, and in Dependence on the Baseline Level, Inflammation in Hemodialysis Patients

BACKGROUND

Hemodialysis (HD) patients are frequently in an elevated inflammatory state which is correlated to the atherosclerosis-related and overall morbidity and mortality in this population. Statins, beyond their antilipidemic effects, are also considered to have anti-inflammatory, immunomodulating and antioxidant properties. The individual response of HD patients to a short course of fluvastatin, the mechanisms involved in the immunomodulating and anti-inflammatory effects of this drug and the time interval to the appearance of these effects are investigated in this longitudinal study.

METHODS

In a group of 51 HD patients, fluvastatin 40 mg/day was administered for 4 weeks. Serial measurements of the lipid profile, C-reactive protein (CRP), interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), interleukin-10 (IL-10), and serum oxidized LDL (ox-LDL), were performed before, during, and after the treatment period.

RESULTS

Total cholesterol was significantly reduced after 14 days of treatment with fluvastatin (from mean +/- SD 216.7 +/- 34.3 to 179.2 +/- 42.3 mg/dl, p < 0.001). IL-6 and ox-LDL were reduced on day 28 (p < 0.001 and p < 0.01, respectively) and IL-10 was increased on day 14 (p = 0.05); CRP did not change significantly during the treatment period while sIL-6R was increased on day 28 of fluvastatin administration (p < 0.05). In a subgroup of patients with CRP, IL-6, sIL-6R, and ox-LDL baseline serum values > or = the median and IL-10 < or = the median, CRP was reduced on day 28 of fluvastatin treatment (p < 0.01), IL-6 and ox-LDL were reduced earlier, on day 14 (p = 0.05 and p < 0.05, respectively) while sIL-6R did not change significantly during the treatment period.

CONCLUSIONS

Treatment with fluvastatin rapidly modulates inflammation in HD patients. Enhancement of anti-inflammatory mechanisms and attenuation of the inflammatory and oxidative state contribute to this modulation. Patients in an elevated baseline inflammatory state respond more rapidly and effectively to the treatment. This immediate and multi-potent action of the statins could be clinically useful in acute atherosclerosis complications or in the treatment of chronic inflammation in HD patients.

Simvastatin Attenuates Renal Ischemia/Reperfusion Injury in Rats Administered Cyclosporine A

BACKGROUND

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors increase renal blood flow independent of their lipid-lowering properties. In organ transplantation, the calcineurin inhibitor cyclosporine A (CyA) is the immunosuppressant of choice. However, its renal vasoconstrictor properties limit its use. This study aimed to determine the effect of an HMG-CoA reductase inhibitor, simvastatin (Zocor), on renal function in rats after ischemia/reperfusion injury (I/R) with concomitant CyA treatment.

METHODS

Male Wistar rats (250 g) were anesthetized and the suprarenal aorta clamped for 40 minutes. The right kidney was removed. After recovery, the rats were divided into 5 groups: (1) control rats, no ischemia, no treatment; (2) ischemia with no treatment; (3) ischemia plus CyA only; (4) ischemia plus CyA and low-dose simvastatin; and (5) ischemia plus CyA and high-dose simvastatin. Five to 7 days after I/R injury, glomerular filtration rate (GFR) was determined using urinary iohexol clearance.

RESULTS

The GFR values (mL/min) for all 5 groups were as follows: (1) 1.23 +/- 0.08; (2) 1.05 +/- 0.10; (3) 0.44 +/- 0.06 (P < 0.05 versus groups 1, 2, and 5; one-way analysis of variance); (4) 0.51 +/- 0.04 (P < 0.05 versus groups 1, 2, and 5; one-way analysis of variance); and (5) 0.85 +/- 0.11.

CONCLUSIONS

After I/R injury and cyclosporine treatment, simvastatin preserved renal function compared with cyclosporine treatment alone because it may not have a direct vasoconstrictor effect on the renal microcirculation. In fact, it may exhibit vasodilator properties on the renal microcirculation mediated by nitric oxide.

Are HMG-CoA reductase inhibitors underutilized in dialysis patients?

Patients with end-stage renal disease (ESRD) treated with dialysis have a dramatically elevated rate of cardiovascular disease (CVD) compared to the general population. Lipid-lowering therapy with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors ("statins") has been shown to markedly reduce cardiovascular risk in patients without renal failure, but their effect has not been fully studied in the dialysis population. In this article we will first discuss the known benefits of statin therapy in the general population and summarize the current guidelines for such therapy. We will then examine the evidence linking dyslipidemia and cardiac disease in the dialysis population and discuss possible pathophysiologic mechanisms by which statins could prevent cardiac disease in these patients. We will also review prior clinical studies of the effects of statins in patients on dialysis, with particular attention to the safety and efficacy of these drugs in this population. Finally, we will review how statins are currently being used in the care of dialysis patients and suggest whether an expanded utilization of these drugs could help reduce the enormously high rates of cardiac disease in this patient population.