Lipid-lowering long-term effects of six different statins in hypercholesterolemic renal transplant patients under cyclosporine immunosuppression

HMG CoA reductase inhibitors (statins) for kidney transplant recipients

BACKGROUND

People with chronic kidney disease (CKD) have higher risks of cardiovascular disease compared to the general population. Specifically, cardiovascular deaths account most deaths in kidney transplant recipients. Statins are a potentially beneficial intervention for kidney transplant patients given their established benefits in patients at risk of cardiovascular disease in the general population. This is an update of a review first published in 2009.

OBJECTIVES

We aimed to evaluate the benefits (reductions in all-cause and cardiovascular mortality, major cardiovascular events, myocardial infarction and stroke, and progression of CKD to requiring dialysis) and harms (muscle or liver dysfunction, withdrawal, cancer) of statins compared to placebo, no treatment, standard care, or another statin in adults with CKD who have a functioning kidney transplant.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 29 February 2012 through contact with the Trials Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or statins on mortality, cardiovascular events, kidney function and toxicity in kidney transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, glomerular filtration rate (GFR), proteinuria) and relative risk (RR) for dichotomous outcomes (major cardiovascular events, mortality, fatal or non-fatal myocardial infarction, fatal or non-fatal stroke, elevated muscle or liver enzymes, withdrawal due to adverse events, cancer, end-stage kidney disease (ESKD), acute allograft rejection) together with 95% confidence intervals (CI).

MAIN RESULTS

We identified 22 studies (3465 participants); 17 studies (3282 participants) compared statin with placebo or no treatment, and five studies (183 participants) compared two different statin regimens.From data generally derived from a single high-quality study, it was found that statins may reduce major cardiovascular events (1 study, 2102 participants: RR 0.84, CI 0.66 to 1.06), cardiovascular mortality (4 studies, 2322 participants: RR 0.68, CI 0.45 to 1.01), and fatal or non-fatal myocardial infarction (1 study, 2102 participants: RR 0.70, CI 0.48 to 1.01); although effect estimates lack precision and include the possibility of no effect.Statins had uncertain effects on all-cause mortality (6 studies, 2760 participants: RR 1.08, CI 0.63 to 1.83); fatal or non-fatal stroke (1 study, 2102 participants: RR 1.18, CI 0.85 to 1.63); creatine kinase elevation (3 studies, 2233 participants: RR 0.86, CI 0.39 to 1.89); liver enzyme elevation (4 studies, 608 participants: RR 0.62, CI 0.33 to 1.19); withdrawal due to adverse events (9 studies, 2810 participants: RR 0.89, CI 0.74 to 1.06); and cancer (1 study, 2094 participants: RR 0.94, CI 0.82 to 1.07).Statins significantly reduced serum total cholesterol (12 studies, 3070 participants: MD -42.43 mg/dL, CI -51.22 to -33.65); low-density lipoprotein cholesterol (11 studies, 3004 participants: MD -43.19 mg/dL, CI -52.59 to -33.78); serum triglycerides (11 studies, 3012 participants: MD -27.28 mg/dL, CI -34.29 to -20.27); and lowered high-density lipoprotein cholesterol (11 studies, 3005 participants: MD -5.69 mg/dL, CI -10.35 to -1.03).Statins had uncertain effects on kidney function: ESKD (6 studies, 2740 participants: RR 1.14, CI 0.94 to 1.37); proteinuria (2 studies, 136 participants: MD -0.04 g/24 h, CI -0.17 to 0.25); acute allograft rejection (4 studies, 582 participants: RR 0.88, CI 0.61 to 1.28); and GFR (1 study, 62 participants: MD -1.00 mL/min, CI -9.96 to 7.96).Due to heterogeneity in comparisons, data directly comparing differing statin regimens could not be meta-analysed. Evidence for statins in people who have had a kidney transplant were sparse and lower quality due to imprecise effect estimates and provided limited systematic evaluation of treatment harm.

AUTHORS' CONCLUSIONS

Statins may reduce cardiovascular events in kidney transplant recipients, although treatment effects are imprecise. Statin treatment has uncertain effects on overall mortality, stroke, kidney function, and toxicity outcomes in kidney transplant recipients. Additional studies would improve our confidence in the treatment benefits and harms of statins on cardiovascular events in this clinical setting.

Statin therapy ameliorates renal allograft function

BACKGROUND

Statins have proven ability as antilipidemic agents and benefit cardiovascular survival in transplant recipients. The pleiotropic effects of statins on renal function in renal allograft recipients are still undetermined.

METHODS

Statin therapy was initiated according to guidelines for cardiovascular protection. Serum creatinine concentration and estimated glomerular filtration rate (eGFR) were analyzed before and after introduction of statins. The 73 patients who were retrospectively studied included those who were dialysis-dependent. Mean changes in eGFR and lipid profile were compared before and after commencing statins using chi(2) tests.

RESULTS

Mean serum creatinine concentration 18 months before starting statin therapy was 160.13 mumol/L, and 24 months after starting statin therapy was 172.22 mumol/L. Mean eGFR was 53.40 mL/min 18 months before starting statin therapy, and decreased to 49.43 mL/min after starting statin therapy. This represented a decline in renal function of 0.22 mL/min/mo over 18 months. The eGFR at 12 months after beginning statin therapy was 52.67 mL/min, and at 24 months was 49.06 mL/min. The rate of decline of eGFR after starting statin therapy was significantly lower: 0.02 mL/min/mo over 24 months (P < .001). Total cholesterol and low-density lipoprotein cholesterol concentrations were significantly decreased after starting statin therapy (P < .001). Four of 73 patients developed graft failure within 24 months.

CONCLUSION

Statin therapy in our setting was associated with a lower rate of decline in renal function in renal allograft recipients within 2 years of starting treatment.

Novel pharmacological approaches to the treatment of renal ischemia-reperfusion injury: a comprehensive review

Renal ischemia-reperfusion (I-R) contributes to the development of ischemic acute renal failure (ARF). Multi-factorial processes are involved in the development and progression of renal I-R injury with the generation of reactive oxygen species, nitric oxide and peroxynitrite, and the decline of antioxidant protection playing major roles, leading to dysfunction, injury, and death of the cells of the kidney. Renal inflammation, involving cytokine/adhesion molecule cascades with recruitment, activation, and diapedesis of circulating leukocytes is also implicated. Clinically, renal I-R occurs in a variety of medical and surgical settings and is responsible for the development of acute tubular necrosis (a characteristic feature of ischemic ARF), e.g., in renal transplantation where I-R of the kidney directly influences graft and patient survival. The cellular mechanisms involved in the development of renal I-R injury have been targeted by several pharmacological interventions. However, although showing promise in experimental models of renal I-R injury and ischemic ARF, they have not proved successful in the clinical setting (e.g., atrial natriuretic peptide, low-dose dopamine). This review highlights recent pharmacological developments, which have shown particular promise against experimental renal I-R injury and ischemic ARF, including novel antioxidants and antioxidant enzyme mimetics, nitric oxide and nitric oxide synthase inhibitors, erythropoietin, peroxisome-proliferator-activated receptor agonists, inhibitors of poly(ADP-ribose) polymerase, carbon monoxide-releasing molecules, statins, and adenosine. Novel approaches such as recent research involving combination therapies and the potential of non-pharmacological strategies are also considered.

Effect of Statin Treatment on Oxidative Stress and Renal Function in Renal Transplantation

The beneficial action of statins on the lipid profile, cardiovascular disease, and death is well known. Besides their lipid-lowering role, these drugs have pleiotropic action that derive from their prevention of the synthesis of isoprenoids, mediators in cell signaling. Thus, due to their antioxidant capacity, statins can decrease the production of reactive oxygen species by inhibiting NAD(P)H oxidase activity. Previous studies by our group have described increased oxidative stress status in renal transplantation that might benefit from HMG CoA reductase inhibitor therapy. The aim of this study was to assess the influence of statins on stress parameters and their relevance to renal function in kidney transplantation. In 58 transplanted patients a first blood sample was obtained, without statins followed by 21 patients treated with statins (group 1) and 37 patients without drug (group 0) for a 6-month study period. We collected clinical data as well biochemical results on lipid profile, creatinine and oxidative stress. Lipid profile reduction was significant among group 1 compared with group 0. An increased glutathione peroxidase (GPx) among observed in all patients was greater in the statin-treated group (P = .006). No differences in creatinine or Cockroft-Gault values were observed between before versus after drug administration. In conclusion, statin treatment in renal transplantation improves the lipid profile and may increase GPx-measured antioxidant capacity but appears to have no short-term effect on renal function.

Long term efficacy of simvastatin in renal transplant recipients treated with cyclosporine or tacrolimus

BACKGROUND

Hyperlipidemia is frequently developed following renal transplantation and results in worsening of the patient's prognosis.

METHODS

In this study, 14 patients who had hypercholesterolemia [total cholesterol (TC) >200 mg/dL] and hypertriglyceridemia [triglyceride (TG) >150 mg/dL] 1 month after renal transplantation (post-transplantation), seven patients each under the treatment with immunosuppressant, either cyclosporine or tacrolimus started simvastatin treatment of 5-10 mg/d and continued the treatment for 4 yr. The effect of simvastatin treatment was assessed by comparison in serum lipid levels (TC, TG, cholesterol in lipoprotein fractions, and apolipoproteins) and the lipid metabolism related enzyme activities for post-transplantation, after 6-month and 4-yr simvastatin treatment.

RESULTS

Simvastatin treatment of 4 yr significantly decreased the elevated levels of serum TC from 234.5 +/- 30.8 to 186.3 +/- 20.5 mg/dL (p < 0.001), low density lipoprotein cholesterol (LDL-C) from 116.7 +/- 22.5 to 82.7 +/- 16.6 mg/dL (p < 0.05) and TG from 200.3 +/- 109.2 to 97.0 +/- 45.2 mg/dL (p < 0.001). In addition, there were significant decreases in elevated serum very-low-density lipoprotein cholesterol (VLDL-C) from 47.8 +/- 18.4 to 28.6 +/- 9.5 mg/dL (p < 0.001) and LDL2 cholesterol (LDL2-C) from 20.8 +/- 8.2 to 5.7 +/- 1.8 mg/dL (p < 0.001).

CONCLUSION

The results indicate that 4-yr treatment of simvastatin improves profiles of the atherogenic lipids in renal transplant patients with immunosuppressant caused hypercholesterolemia and hypertriglyceridemia treated either cyclosporine or tacrolimus in similar manner.

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

Premature atherosclerotic coronary heart disease driven by multiple risk factors is a major cause of morbidity and mortality among the 6 million patients in the United States with chronic renal failure. Consensus is that kidney failure and renal transplantation patients should be treated aggressively for dyslipidemia. Major medical literature databases were searched for published information about fluvastatin, a HMG-CoA reductase inhibitor, used in patients with impaired renal function. This article characterizes the dyslipidemia observed in these clinical settings and reviews the clinical experience with fluvastatin.

Assessing the relative risk of cardiovascular disease among renal transplant patients receiving tacrolimus or cyclosporine

Calcineurin inhibitors potentially contribute to risk of cardiovascular events through the development of new-onset diabetes mellitus, hypertension and hyperlipidemia. The exact extent to which calcineurin inhibitors affect these risk factors is difficult to establish since pre-existing renal disease and concomitant immunosuppressive agents (such as steroids or TOR inhibitors) also exert an effect. Clinical trials have consistently shown a higher incidence of new-onset diabetes mellitus with tacrolimus, which has been borne out in large-scale registry analyses. However, the risk of hypertension is approximately 5% higher with cyclosporine than tacrolimus, as is the risk of hyperlipidemia. Statin therapy is effective in treating dyslipidemia and has significant benefits in renal transplant patients. An individualized approach to choice of calcineurin inhibitor, by which cyclosporine or tacrolimus are selected based on the patient's particular risk profile, may thus help to reduce the toll of cardiovascular mortality among renal transplant recipients in the future.

Emerging drugs for renal failure

Renal failure involves a significant impairment of the essential functions of the kidney, which can be either acute with sudden and rapid onset (acute renal failure [ARF]) or chronic with gradual onset (chronic renal failure [CRF]). ARF, if detected early, may be halted or reversed, whereas CRF is generally irreversible. Without treatment or intervention, both forms of renal failure lead to end stage renal failure (ESRF) or end stage renal disease (ESRD), requiring renal replacement therapy (RRT) in the form of dialysis or renal transplantation for survival. However, provision of RRT requires expert teams working in specialised units, making therapy of patients with renal failure expensive; furthermore, RRT is complex, with its own complications. Although pharmacological interventions have shown promise in experimental models, these have not been as successful in the clinical setting (e.g., administration of atrial natriuretic peptide, low-dose dopamine). At present, drugs are administered during CRF to either reduce one of the many risk factors of CRF (e.g., angiotensin-converting enzyme inhibitors, statins) or to deal with the consequences of CRF (e.g., erythropoietin, calcitriol). Recent evidence suggests that some of these interventions may provide further direct beneficial effects via reduction of renal inflammation. Although these interventions have greatly improved the prospects for patients suffering ESRF, the development of novel drugs and therapies with which to reduce the consequences of renal failure and ESRD remain topics of great interest. This article reviews the therapies available for the prevention and management of renal failure in adults and describes, in detail, emerging drugs and novel interventions that may soon become available for the treatment or prevention of ESRF.

Pancreas transplantation: indications and consequences

Pancreas transplantation continues to evolve as a strategy in the management of diabetes mellitus. The first combined pancreas-kidney transplant was reported in 1967, but pancreas transplant now represents a number of procedures, each with different indications, risks, benefits, and outcomes. This review will summarize these procedures, including their risks and outcomes in comparison to kidney transplantation alone, and how or if they affect the consequences of diabetes: hyperglycemia, hypoglycemia, and microvascular and macrovascular complications. In addition, the new risks introduced by immunosuppression will be reviewed, including infections, cancer, osteoporosis, reproductive function, and the impact of immunosuppression medications on blood pressure, lipids, and glucose tolerance. It is imperative that an endocrinologist remain involved in the care of the pancreas transplant recipient, even when glucose is normal, because of the myriad of issues encountered post transplant, including ongoing management of diabetic complications, prevention of bone loss, and screening for failure of the pancreas graft with reinstitution of treatment when indicated. Although long-term patient and graft survival have improved greatly after pancreas transplant, a multidisciplinary team is needed to maximize long-term quality, as well as quantity, of life for the pancreas transplant recipient.

Therapeutic Considerations for the Use of Statin Therapy in Chronic Renal Disease

This review presents an evidence-based analysis of the use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) in patients with chronic renal disease. It considers the characteristics and incidence of dyslipidaemia among specific patient types and describes the available data concerning the ability of statin therapy to regulate dyslipidaemia in the renal disease population as well as early results for an anti-inflammatory effect in this group. The clinical impact of statins in terms of reduced morbidity and mortality is also discussed. The relative merits of different statin agents are reviewed in terms of efficacy and safety, together with the role of aggressive intervention as compared with standard approaches to care. Finally, a proposed algorithm for the initiation and monitoring of statin therapy in chronic renal disease patients is presented.

Rhabdomyolysis associated with hydroxymethylglutaryl-coenzyme A reductase inhibitors

BACKGROUND

The recent withdrawal of cerivastatin by the manufacturer has led to an interest in hydroxymethylglutaryl-coenzyme A (HMG-CoA) inhibitors and the incidence of myopathy. We review the epidemiology, pharmacology, and presumed mechanisms of statin-induced myopathy, with a particular focus on cerivastatin.

METHODS

A MEDLINE search of English-language articles published between 1985 and 2003 was performed. Key words included HMG-CoA inhibitors, statins, myopathy, myotoxicity, rhabdomyolysis, adverse events, drug interactions, and cerivastatin.

RESULTS

The initial trials, which assessed the efficacy of first-generation HMG-CoA inhibitors, did not show a clinically significant increase in the incidence of myopathy. However, on the basis of Food and Drug Administration post-marketing surveys, the rate of cerivastatin-induced rhabdomyolysis appeared to be 10-fold greater than that of the other statins, despite safe pre-clinical profiles. However, no clinical trials have been performed directly comparing the rates of myotoxicity of all commercially available statins. The mechanism of statin-induced myopathy remains unclear. The prevailing theory is that lipophilic statins lead to depletion of intermediates normally formed after cholesterol synthesis within myocytes. Risk factors for the development of myopathy include drug interactions (especially with fibrates) and the coexistence of conditions known to predispose patients to rhabdomyolysis.

CONCLUSION

The cerivastatin experience emphasizes the need for large safety trials before drug approval and for vigilant post-marketing surveillance. Further research and sound clinical judgment may lead to the identification of high-risk individuals in whom statins should be avoided.

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.

Potential nontraditional applications of statins

OBJECTIVE

To review the current evidence for use of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) in nontraditional lipid-related applications, including acute coronary syndromes, peripheral arterial disease, stroke, and renal disease, and to describe ongoing trials evaluating the role of statins in these conditions.

DATA SOURCES

Clinical literature was identified by a MEDLINE search (1990-November 2002) using >/=1 of the following search terms: acute coronary syndrome(s), angina pectoris, atherosclerosis, atorvastatin, clinical trials, diabetes mellitus, end-stage renal disease, fluvastatin, lovastatin, myocardial infarction, peripheral arterial disease, pravastatin, simvastatin, statins, and stroke. Treatment guidelines issued by professional and governmental organizations, such as the American Diabetes Association, American Heart Association, National Cholesterol Education Program, National Kidney Foundation, and National Stroke Foundation, were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Articles identified from the data sources were included if they pertained to the conditions described in the objectives and provided unique information concerning use of statins.

DATA SYNTHESIS

Substantial evidence exists for the use of statins in acute coronary syndromes. Meta-analyses of data from major clinical trials indicate that statins prevent first and recurrent stroke, and large-scale trials are underway to evaluate the efficacy of statins in this setting. Accumulating evidence suggests that statins may be beneficial in reducing the morbidity and mortality associated with peripheral arterial disease and end-stage renal disease, and results from ongoing trials may confirm these benefits. Statins may also have a future role in amelioration of other conditions associated with atherosclerosis, such as diabetes mellitus.

CONCLUSIONS

A large body of evidence supports the evaluation of statins in clinical settings beyond primary and secondary prevention of morbidity and mortality associated with coronary atherosclerosis.