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

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

BACKGROUND

Cardiovascular disease is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), and the absolute risk of cardiovascular events is similar to people with coronary artery disease. This is an update of a review first published in 2009 and updated in 2014, which included 50 studies (45,285 participants).

OBJECTIVES

To evaluate the benefits and harms of statins compared with placebo, no treatment, standard care or another statin in adults with CKD not requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 4 October 2023. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. An updated search will be undertaken every three months.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on death, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD (estimated glomerular filtration rate (eGFR) 90 to 15 mL/min/1.73 m2) were included.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed the study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous benefits and harms with 95% confidence intervals (CI). The risk of bias was assessed using the Cochrane risk of bias tool, and the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 63 studies (50,725 randomised participants); of these, 53 studies (42,752 participants) compared statins with placebo or no treatment. The median duration of follow-up was 12 months (range 2 to 64.8 months), the median dosage of statin was equivalent to 20 mg/day of simvastatin, and participants had a median eGFR of 55 mL/min/1.73 m2. Ten studies (7973 participants) compared two different statin regimens. We were able to meta-analyse 43 studies (41,273 participants). Most studies had limited reporting and hence exhibited unclear risk of bias in most domains. Compared with placebo or standard of care, statins prevent major cardiovascular events (14 studies, 36,156 participants: RR 0.72, 95% CI 0.66 to 0.79; I2 = 39%; high certainty evidence), death (13 studies, 34,978 participants: RR 0.83, 95% CI 0.73 to 0.96; I² = 53%; high certainty evidence), cardiovascular death (8 studies, 19,112 participants: RR 0.77, 95% CI 0.69 to 0.87; I² = 0%; high certainty evidence) and myocardial infarction (10 studies, 9475 participants: RR 0.55, 95% CI 0.42 to 0.73; I² = 0%; moderate certainty evidence). There were too few events to determine if statins made a difference in hospitalisation due to heart failure. Statins probably make little or no difference to stroke (7 studies, 9115 participants: RR 0.64, 95% CI 0.37 to 1.08; I² = 39%; moderate certainty evidence) and kidney failure (3 studies, 6704 participants: RR 0.98, 95% CI 0.91 to 1.05; I² = 0%; moderate certainty evidence) in people with CKD not requiring dialysis. Potential harms from statins were limited by a lack of systematic reporting. Statins compared to placebo may have little or no effect on elevated liver enzymes (7 studies, 7991 participants: RR 0.76, 95% CI 0.39 to 1.50; I² = 0%; low certainty evidence), withdrawal due to adverse events (13 studies, 4219 participants: RR 1.16, 95% CI 0.84 to 1.60; I² = 37%; low certainty evidence), and cancer (2 studies, 5581 participants: RR 1.03, 95% CI 0.82 to 1.30; I² = 0%; low certainty evidence). However, few studies reported rhabdomyolysis or elevated creatinine kinase; hence, we are unable to determine the effect due to very low certainty evidence. Statins reduce the risk of death, major cardiovascular events, and myocardial infarction in people with CKD who did not have cardiovascular disease at baseline (primary prevention). There was insufficient data to determine the benefits and harms of the type of statin therapy.

AUTHORS' CONCLUSIONS

Statins reduce death and major cardiovascular events by about 20% and probably make no difference to stroke or kidney failure in people with CKD not requiring dialysis. However, due to limited reporting, the effect of statins on elevated creatinine kinase or rhabdomyolysis is unclear. Statins have an important role in the primary prevention of cardiovascular events and death in people who have CKD and do not require dialysis. Editorial note: This is a living systematic review. We will search for new evidence every three months and update the review when we identify relevant new evidence. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Perioperative Acute Kidney Injury

Perioperative organ injury is among the leading causes of morbidity and mortality of surgical patients. Among different types of perioperative organ injury, acute kidney injury occurs particularly frequently and has an exceptionally detrimental effect on surgical outcomes. Currently, acute kidney injury is most commonly diagnosed by assessing increases in serum creatinine concentration or decreased urine output. Recently, novel biomarkers have become a focus of translational research for improving timely detection and prognosis for acute kidney injury. However, specificity and timing of biomarker release continue to present challenges to their integration into existing diagnostic regimens. Despite many clinical trials using various pharmacologic or nonpharmacologic interventions, reliable means to prevent or reverse acute kidney injury are still lacking. Nevertheless, several recent randomized multicenter trials provide new insights into renal replacement strategies, composition of intravenous fluid replacement, goal-directed fluid therapy, or remote ischemic preconditioning in their impact on perioperative acute kidney injury. This review provides an update on the latest progress toward the understanding of disease mechanism, diagnosis, and managing perioperative acute kidney injury, as well as highlights areas of ongoing research efforts for preventing and treating acute kidney injury in surgical patients.

Long-term effects of various types of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on changes in glomerular filtration rate in Korea

Few long-term follow-up studies have compared the changes in renal function according to the type of statin used in Korea. We compared the long-term effects of statin intensity and type on the changes in the glomerular filtration rate (GFR). We extracted data of patients who took statin for the first time. We analyzed whether or not different statins affect the changes in GFR at 3 months after baseline and 4 years after. We included 3678 patients and analyzed the changes in GFR. The GFR decreased by 3.2% ± 0.4% on average 4 years after the first statin prescription, indicating statistically significant deterioration (from 83.5 ± 0.4 mL/min/1.73 m² to 79.9 0.4 mL/min/1.73 m², P < 0.001). When comparing the GFR among different statins, significant differences were observed between atorvastatin and fluvastatin (-5.3% ± 0.7% vs. 1.2% ± 2.2%, P < 0.05) and between atorvastatin and simvastatin (-5.3% ± 0.7% vs. -0.7% ± 0.8%, P < 0.05). In pitavastatin (odds ratio [OR]= 0.64, 95% confidence interval [CI]= 0.46-0.87, P < 0.005) and simvastatin (OR = 0.69, 95% CI = 0.53-0.91, P < 0.008), the GFR rate that decreased by < 60 mL/min/1.73 m² was significantly lower than that of atorvastatin. Regarding long-term statin intake, GFR changed with the type of statin. This work is the first in Korea to compare each statin in terms of changes in the GFR after the statin prescription.

The Effects of Simvastatin on Proteinuria and Renal Function in Patients with Chronic Kidney Disease

Current data suggests that statins might have beneficial effects on renal outcomes. Beneficial effects of statin treatment on renal progression in advanced chronic kidney disease (CKD) are obviously controversial. In a retrospective, controlled study, the authors have evaluated the effects of 53-week treatment with simvastatin, versus no treatment on proteinuria and renal function among 51 patients with CKD stages III-IV. By the end of the 53-week treatment, urine protein excretion decreased from 0.96 (IQR 0.54, 2.9) to 0.48 (IQR 0.18, 0.79) g/g creatinine (P < 0.001) in patients treated with simvastatin in addition to ACEI and ARBs, while no change was observed among the untreated patients. Moreover, a significantly greater decrease in urine protein excretion was observed in the simvastatin group as compared with the untreated group. The mean changes of serum creatinine and eGFR did not significantly differ in both groups. A significantly greater decrease in total cholesterol and LDL-cholesterol was found in the simvastatin group than in the untreated group. In summary, apart from lipid lowering among CKD patients, ingesting simvastatin was associated with a decrease in proteinuria. These statin effects may become important for supportive therapy in renal damage in the future.

Should we use statins in all patients with chronic kidney disease without dialysis therapy? The current state of knowledge

PURPOSE

The aim of this article was to present the most important matters associated with dyslipidemia treatment in CKD patients. Moreover, the most important recommendations of the current (2013) KDIGO clinical practice guideline for lipid management in chronic kidney disease are presented.

METHODS

Authors looked through the most recent large clinical trials and meta-analyses and presented their results. We searched using the electronic databases [MEDLINE, EMBASE, Scopus, DARE]. Additionally, abstracts from national and international cardiovascular meetings were studied.

RESULTS

Analysis results suggest that statins exert beneficial effects on kidney since they considerably reduce 24 h urinary protein excretion and are associated with a rise in GFR. Beneficial effects of statins may be influenced by kidney disease stage, doses of medicine and treatment duration. Data suggest that statins are effective and safe for secondary prevention of CV events in individuals with mild CKD. Patients treated with statins had decreased frequency of major atherosclerotic events compared with placebo, reduced risk of CV mortality and deaths from all causes.

CONCLUSIONS

Meta-analyses results suggest that statins are associated with lipid lowering, cardiovascular and anti-proteinuric benefits in CKD patients. However, their effects on overall and cardiovascular mortality are much less obvious. Bearing in mind the advantageous effects and low risk of adverse effects, it seems that mild renal impairment should not exclude these patients from receiving a statin. However, because CKD patients in stages III-V are underrepresented in clinical trials, administration of statins to these patients who have not yet had a vascular event remains controversial.

Potential Renoprotective Agents through Inhibiting CTGF/CCN2 in Diabetic Nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). The development and progression of DN might involve multiple factors. Connective tissue growth factor (CCN2, originally known as CTGF) is the one which plays a pivotal role. Therefore, increasing attention is being paid to CCN2 as a potential therapeutic target for DN. Up to date, there are also many drugs or agents which have been shown for their protective effects against DN via different mechanisms. In this review, we only focus on the potential renoprotective therapeutic agents which can specifically abolish CCN2 expression or nonspecifically inhibit CCN2 expression for retarding the development and progression of DN.

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

BACKGROUND

Cardiovascular disease (CVD) is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), for whom the absolute risk of cardiovascular events is similar to people who have existing coronary artery disease. This is an update of a review published in 2009, and includes evidence from 27 new studies (25,068 participants) in addition to the 26 studies (20,324 participants) assessed previously; and excludes three previously included studies (107 participants). This updated review includes 50 studies (45,285 participants); of these 38 (37,274 participants) were meta-analysed.

OBJECTIVES

To evaluate the benefits (such as reductions in all-cause and cardiovascular mortality, major cardiovascular events, MI and stroke; and slow progression of CKD to end-stage kidney disease (ESKD)) and harms (muscle and liver dysfunction, withdrawal, and cancer) of statins compared with placebo, no treatment, standard care or another statin in adults with CKD who were not on dialysis.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 5 June 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on mortality, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD not on dialysis were the focus of our literature searches.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, creatinine clearance and proteinuria) and risk ratio (RR) for dichotomous outcomes (major cardiovascular events, all-cause mortality, cardiovascular mortality, fatal or non-fatal myocardial infarction (MI), fatal or non-fatal stroke, ESKD, elevated liver enzymes, rhabdomyolysis, cancer and withdrawal rates) with 95% confidence intervals (CI).

MAIN RESULTS

We included 50 studies (45,285 participants): 47 studies (39,820 participants) compared statins with placebo or no treatment and three studies (5547 participants) compared two different statin regimens in adults with CKD who were not yet on dialysis. We were able to meta-analyse 38 studies (37,274 participants).The risk of bias in the included studies was high. Seven studies comparing statins with placebo or no treatment had lower risk of bias overall; and were conducted according to published protocols, outcomes were adjudicated by a committee, specified outcomes were reported, and analyses were conducted using intention-to-treat methods. In placebo or no treatment controlled studies, adverse events were reported in 32 studies (68%) and systematically evaluated in 16 studies (34%).Compared with placebo, statin therapy consistently prevented major cardiovascular events (13 studies, 36,033 participants; RR 0.72, 95% CI 0.66 to 0.79), all-cause mortality (10 studies, 28,276 participants; RR 0.79, 95% CI 0.69 to 0.91), cardiovascular death (7 studies, 19,059 participants; RR 0.77, 95% CI 0.69 to 0.87) and MI (8 studies, 9018 participants; RR 0.55, 95% CI 0.42 to 0.72). Statins had uncertain effects on stroke (5 studies, 8658 participants; RR 0.62, 95% CI 0.35 to 1.12).Potential harms from statin therapy were limited by lack of systematic reporting and were uncertain in analyses that had few events: elevated creatine kinase (7 studies, 4514 participants; RR 0.84, 95% CI 0.20 to 3.48), liver function abnormalities (7 studies, RR 0.76, 95% CI 0.39 to 1.50), withdrawal due to adverse events (13 studies, 4219 participants; RR 1.16, 95% CI 0.84 to 1.60), and cancer (2 studies, 5581 participants; RR 1.03, 95% CI 0.82 to 130).Statins had uncertain effects on progression of CKD. Data for relative effects of intensive cholesterol lowering in people with early stages of kidney disease were sparse. Statins clearly reduced risks of death, major cardiovascular events, and MI in people with CKD who did not have CVD at baseline (primary prevention).

AUTHORS' CONCLUSIONS

Statins consistently lower death and major cardiovascular events by 20% in people with CKD not requiring dialysis. Statin-related effects on stroke and kidney function were found to be uncertain and adverse effects of treatment are incompletely understood. Statins have an important role in primary prevention of cardiovascular events and mortality in people who have CKD.

Protective effect of statin therapy on connective tissue growth factor induction by diabetes in vivo and high glucose in vitro

Transcriptional activity of connective tissue growth factor (CTGF) promoter in transfected HEK293 cells was determined by luciferase assays. Secreted CTGF in cultured human mesangial cells was measured by enzyme-linked immunosorbent assay (ELISA). CTGF in urine and plasma was also measured in 405 subjects with/without type 2 diabetes. Our results showed that high glucose significantly increased transcription of the promoter in the transfected cells by more than 2.5-folds (p < 0.0005). CTGF secretion was induced by high glucose in the cells (p < 0.0005). These increases were inhibited by simvastatin. Urine CTGF was positively associated with plasma CTGF in both type 2 diabetes (p = 0.0005) and controls (p = 0.01). Urine CTGF levels in patients with macroalbuminuria were significantly higher than patients without macroalbuminuria (p < 0.05). In conclusion, our in vitro study suggests that statin may have a renal-protective effect through the inhibition of CTGF expression. Urine CTGF may be a good marker for the prediction of diabetic nephropathy.

A meta-analysis of the role of statins on renal outcomes in patients with chronic kidney disease. Is the duration of therapy important?

INTRODUCTION

The efficacy of statin treatment in chronic kidney disease (CKD) patients remains controversial. Therefore, we performed a meta-analysis to investigate whether statins modulate renal function in patients with CKD.

METHODS

Data from Scopus, PubMed, Web of Science, and the Cochrane Central Register of randomized controlled trials for years 1966-December 2012 were searched for appropriate studies.

RESULTS

Twenty trials with 6452 CKD subjects randomized to receive either statin or placebo were included. Statin therapy significantly influenced high sensitivity C-reactive protein levels in patients on or off dialysis [-0.28 mg/dl, 95%CI: -0.93 to -0.37; p<0.05 and -0.46 mg/dl, 95%CI: -0.87 to -0.05; p=0.03], respectively], urinary protein (-0.77 g/24 h, 95%CI: -1.24 to -0.29, p<0.02; this effect persisted for treatment ≤12 months), and serum creatinine but only for long-term therapy (3 years) (-0.65 mg/dl, 95%CI: -1.00 to -0.30; p=0.0003). The summary for standardized effect size of mean differences of glomerular filtration rate was 0.29 ml/min/1.73 m(2) (95%CI: 0.01 to 0.58; p=0.04), and depended on treatment duration - a significant increase was observed for between 1 and 3 years of statin therapy (0.50 ml/min/1.73 m(2), 95%CI: 0.40 to 0.60; p<0.0001), with no significant increase for both ≤1 and >3 years of the therapy.

CONCLUSION

Statins might exert significant renoprotective effects in CKD patients; however, benefit may depend on the duration of treatment. This is an issue that warrants more definitive investigation. More studies are necessary in dialysis patients to credibly evaluate the renal effects of statin therapy.

A multi-center, dose-escalation study of human type I pancreatic elastase (PRT-201) administered after arteriovenous fistula creation

Purpose

To explore the safety and efficacy of PRT-201.

Methods

Randomized, double-blind, placebo-controlled, single-dose escalation study of PRT-201 (0.0033 to 9 mg) applied after arteriovenous fistula (AVF) creation. Participants were followed for one year. The primary outcome measure was safety. Efficacy measures were the proportion with intra-operative increases in AVF outflow vein diameter or blood flow ≥25% (primary), changes in outflow vein diameter and blood flow, AVF maturation and lumen stenosis by ultrasound criteria and AVF patency.

Results

The adverse events in the PRT-201 group (n=45) were similar to those in the placebo group (n=21). There were no differences in the proportion with ≥25% increase in vein diameter or blood flow, successful maturation or lumen stenosis. There was no statistically significant difference in primary patency between the dose groups (placebo n=21, Low Dose n=16, Medium Dose n=17 and High Dose n=12). In a subgroup analysis that excluded three participants with early surgical failures, the hazard ratio (HR) for primary patency loss of Low Dose compared with placebo was 0.38 (95% CI 0.10-1.41, P=0.15). In a Cox model, Low Dose (HR 0.27, 95% CI 0.04-0.79, P=0.09), white race (HR 0.17, 95% CI 0.03-0.79, P=0.02), and age <65 years (HR 0.25, CI 0.05-1.15, P=0.08) were associated (P<0.10) with a decreased risk of primary patency loss.

Conclusions

PRT-201 was not different from placebo for safety or efficacy measures. There was a suggestion for improved AVF primary patency with Low Dose PRT-201 that is now being studied in a larger clinical trial.

The effect of statin therapy on the formation of arteriovenous fistula stenoses and the rate of reoccurrence of previously treated stenoses

Statins reduce inflammation in end-stage renal disease patients and improve endothelial function beyond cholesterol lowering. Despite this, statins do not improve the maturation rate, primary patency rate, and the cumulative survival of arteriovenous fistulas (AVFs). It is unknown if statins decrease the number of stenoses developing in AVFs or prolong the intervals between angioplasties needed to treat recurring stenoses. We conducted a retrospective chart review of our 265 active dialysis patients. The statin group was significantly more likely to be diabetic (64% vs. 43.6%) and treated with aspirin (64% vs. 40%) when compared to those not treated with statins (P=0.04 and 0.01). The mean time to first intervention (primary patency) was 16.5 months in statin users and 15.8 months in the nonstatin group (P=0.49) with standard deviations of ± 18.5 and 16.6 months, respectively. Statin use was not associated with a significant decrease in the number of stenoses diagnosed (P=0.28). The mean time between recurrent stenoses' angioplasties was 8.9 months in statin users and 7.3 months in the nonstatin patients (P=0.25). Aspirin users were more likely to have a decreased primary patency (rate ratio=1.65, P=0.03) compared with nonaspirin users. Patients who were prescribed aspirin developed 1.6 (P 0.01) times more stenoses than those not treated with aspirin. We report for the first time that statin therapy does not decrease the number of stenotic lesions developing in the AVF or prolong the interval between procedures required to treat recurrent stenoses.

Combination therapy with an angiotensin II receptor blocker and an HMG-CoA reductase inhibitor in experimental subtotal nephrectomy

BACKGROUND

Angiotensin receptor 1 blockers (ARB) are standard nephroprotective drugs in chronic kidney disease. There is less evidence for a nephroprotective effect of HMG-CoA reductase inhibitors (statins) and much less is known about potential benefits of combination therapy. We evaluated the therapeutic potential of a statin alone or in combination with an ARB in experimental chronic kidney disease.

METHODS

Subtotally nephrectomized (5/6 Nx) rats were treated early with vehicle, losartan, cerivastatin or losartan/cerivastatin. Expression of messenger RNA (mRNA) was assessed by real-time reverse transcription-polymerase chain reaction. Tissue proteins were localized by immunohistochemistry. Nuclear factor-κB (NF-κB) activation was measured in whole kidneys.

RESULTS

In contrast to the sham group, at 6 weeks, vehicle-treated 5/6 Nx rats displayed renal lesions, albuminuria and increased blood pressure, serum creatinine and total kidney NF-κB p65 DNA-binding activity and preproendothelin-1, fibronectin and type I and III collagen mRNA. NF-κB activation correlated with albuminuria and histological renal injury. Losartan or combination therapy preserved renal function, abrogated albuminuria and improved glomerular and interstitial histology. Cerivastatin alone preserved renal function and improved interstitial injury but did not influence albuminuria, glomerular histology or NF-κB activation. Losartan/cerivastatin normalized kidney NF-κB activation and extracellular matrix mRNA expression pattern. The effect of losartan alone on these parameters was less intense. All treatments decreased preproendothelin-1 mRNA and preserved interstitial capillaries.

CONCLUSIONS

In a chronic kidney disease model, early treatment with either an ARB or a statin preserved renal function although the mechanisms differed. Combination therapy with an ARB and a statin did not confer clear-cut advantages on biochemical and histological parameters over ARB alone, although it further improved the kidney NF-κB and gene expression profile.

Statins reverse renal inflammation and endothelial dysfunction induced by chronic high salt intake

High salt intake (HS) is a risk factor for cardiovascular and kidney disease. Indeed, HS may promote blood-pressure-independent tissue injury via inflammatory factors. The lipid-lowering 3-hydroxy 3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors exert beneficial lipid-independent effects, reducing the expression and synthesis of inflammatory factors. We hypothesized that HS impairs kidney structure and function in the absence of hypertension, and these changes are reversed by atorvastatin. Four groups of rats were treated for 6 wk in metabolic cages with their diets: normal salt (NS); HS, NS plus atorvastatin and HS plus atorvastatin. We measured basal and final body weight, urinary sodium and protein excretion (UProtV), and systolic blood pressure (SBP). At the end of the experimental period, cholesterolemia, creatinine clearance, renal vascular reactivity, glomerular volume, cortical and glomerular endothelial nitric oxide synthase (eNOS), and transforming growth factor (TGF)-β1 expression were measured. We found no differences in SBP, body weight, and cholesterolemia. HS rats had increased creatinine clearence, UProtV, and glomerular volume at the end of the study. Acetylcholine-induced vasodilatation decreased by 40.4% in HS rats ( P < 0.05). HS decreased cortical and glomerular eNOS and caused mild glomerular sclerosis, interstitial mononuclear cell infiltration, and increased cortical expression of TGF-β1. All of these salt-induced changes were reversed by atorvastatin. We conclude that long-term HS induces inflammatory and hemodynamic changes in the kidney that are independent of SBP. Atorvastatin corrected all, suggesting that the nitric oxide-oxidative stress balance plays a significant role in the earlier stages of salt induced kidney damage.

Atorvastatin improving renal ischemia reperfusion injury via direct inhibition of active caspase-3 in rats

Caspase-3 is a key molecule involved in the inflammation and apoptosis of ischemia reperfusion (IR) injury. Statins are known to inhibit IR injury, but the mechanism of action remains uncertain. In the present study, the effect and underlying mechanism of ischemia alone, and reperfusion with or without atorvastatin (AT) as a timed intervention were examined, since clinically the kidney is only exposed to drug delivery during reperfusion. Male Sprague‐Dawley rats were subjected to 45‐min clamping of the left renal hilus followed by four hours reperfusion with a right nephrectomy. AT 10 mg/kg was intravenously administered after clamping the renal hilus, but prior to kidney reperfusion. Ischemia alone did cause tubulointerstitial damage (TID), protein carbonylation and caspase-3 activation with an increase in 12 kDa subunit, while reperfusion further enhanced TID, monocyte (ED-1+ cell) infiltration, apoptosis and necrosis together with caspase-3 activity and 17 kDa subunit, but reversed protein carbonylation. AT significantly reduced TID (26%), ED-1+ cell infiltration (74%), tubular apoptosis (47%) and necrosis (73%), and interstitial apoptosis (64%), as well as caspase-3 activity (26%), but did not change serum creatinine and cholesterol. Importantly, without affecting either caspase-3 active protein cleavage or S-nitrosylation, AT directly inhibited caspase-3 active enzyme in a dose-dependent manner in vitro. In conclusions, IR and AT exerted opposing effects on caspase-3 activity by differing mechanisms, with IR stimulating caspase-3 proteolytic cleavage and AT inhibiting active caspase-3 enzyme. This new inhibitory mechanism of AT may improve reperfusion tolerance in ischemic kidneys and benefit transplant recipients.

Rosuvastatin prevents proteinuria and renal inflammation in nitric oxide-deficient rats

OBJECTIVE

The aim of the present study was to assess the effects of rosuvastatin on renal injury and inflammation in a model of nitric oxide deficiency.

METHODS

Male Wistar rats were randomly divided into four groups (n = 10/group) and treated for 28 days with saline (CTRL); 30 mg/kg/day L-NAME (L-name); L-NAME and 20 mg/kg/day rosuvastatin (L-name+ROS-20); or L-NAME and 2 mg/kg/day rosuvastatin (L-name+ROS-2). Systolic blood pressure was measured by plethysmography in the central artery of the tail. The serum total cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, creatinine, nitric oxide, interleukin-6, and tumor necrosis factor alpha levels were analyzed. Urine samples were taken to measure the albumin: urinary creatinine ratio. Kidneys were sectioned and stained with hematoxylin/eosin and Masson's trichrome. Immunohistochemical analysis of the renal tissue was performed to detect macrophage infiltration of the glomeruli.

RESULTS

The systolic blood pressure was elevated in the L-name but not the L-name+rosuvastatin-20 and L-name+rosuvastatin-2 groups. The L-name group had a significantly reduced nitric oxide level and an increased interleukin-6 and tumor necrosis factor alpha level, albumin: urinary creatinine ratio and number of macrophages in the renal glomeruli. Rosuvastatin increased the nitric oxide level in the L-name+rosuvastatin-2 group and reduced the interleukin-6 and tumor necrosis factor alpha levels, glomerular macrophage number and albumin:urinary creatinine ratio in the L-name+rosuvastatin-20 and L-name+rosuvastatin-2 groups.

CONCLUSION

Rosuvastatin treatment reduced glomerular damage due to improvement in the inflammatory pattern independent of the systolic blood pressure and serum lipid level. These effects may lead to improvements in the treatment of kidney disease.

Early statin use is an independent predictor of long-term graft survival

Background. Statin use in renal transplantation has been associated with a lower risk of patient death but not with an improvement of graft functional survival. The aim of this study is to evaluate the effect of statin use in graft survival, death-censored graft survival and patient survival using the data recorded on the Spanish Late Allograft Dysfunction Study Group.

Patients and methods. Patients receiving a renal allograft in Spain in 1990, 1994, 1998 and 2002 were considered. Since the mean follow-up in the 2002 cohort was 3 years, statin use was analysed considering its introduction during the first year or during the initial 2 years after transplantation. Univariate and multivariate Cox regression analyses with a propensity score for statin use were employed to analyse graft survival, death-censored graft survival and patient survival.

Results. In the 4682 evaluated patients, the early statin use after transplantation significantly increased from 1990 to 2002 (12.7%, 27.9%, 47.7% and 53.0%, P < 0.001). Statin use during the first year was not associated with graft or patient survival. Statin use during the initial 2 years was associated with a lower risk of graft failure (relative risk [RR] = 0.741 and 95% confidence interval [CI] = 0.635–0.866, P < 0.001) and patient death (RR = 0.806 and 95% CI = 0.656–0.989, P = 0.039). Death-censored graft survival was not associated with statin use during the initial 2 years.

Conclusion. The early introduction of statin treatment after transplantation is associated with a significant decrease in late graft failure due to a risk reduction in patient death.

The effect of rosuvastatin on insulin sensitivity and pancreatic beta-cell function in nondiabetic renal transplant recipients

Interventions to attenuate abnormal glycemia posttransplantation are required. In addition, surrogate markers of declining glycemic control are valuable. Statins may have pleiotropic properties that attenuate abnormal glucose metabolism. We hypothesized statins would improve glucose metabolism and HbA1c would be advantageous as a surrogate for worsening glycemia. We conducted a prospective, randomized, placebo controlled, crossover study in 20 nondiabetic renal transplant recipients at low risk for NODAT and compared effects of rosuvastatin on insulin secretion/sensitivity. Mathematical model analysis of an intravenous glucose tolerance test determined first-phase insulin secretion, insulin sensitivity and disposition index. Second-phase insulin secretion was determined with a meal tolerance test. Biochemical/clinical parameters were also assessed. Rosuvastatin significantly improved total cholesterol (-30%, p < 0.001), LDL cholesterol (-44%, p < 0.001) and triglycerides (-19%, p = 0.013). C-reactive protein decreased but failed to achieve statistical significance (-31%, p = 0.097). Rosuvastatin failed to influence any glycemic physiological parameter, although an inadequate timeframe to allow pleiotropic mechanisms to clinically manifest raises the possibility of a type II statistical error. On multivariate analysis, glycated hemoglobin (HbA1c) correlated with disposition index (R(2)= 0.201, p = 0.006), first-phase insulin secretion (R(2)= 0.106, p = 0.049) and insulin sensitivity (R(2)= 0.136, p = 0.029). Rosuvastatin fails to modify glucose metabolism in low-risk patients posttransplantation but HbA1c is a useful surrogate for declining glycemic control.

Emerging therapies for chronic kidney disease: what is their role?

The prevalence of chronic kidney disease (CKD) is increasing worldwide. The best therapies currently available focus on the control of blood pressure and optimization of renin-angiotensin-aldosterone system blockade. Currently available agents are only partially effective against hard end points such as the development of end-stage renal disease and are not discussed in this Review. Many other agents have been shown to reduce proteinuria and delay progression in animal models of CKD. Some of these agents, including tranilast, sulodexide, thiazolidinediones, pentoxifylline, and inhibitors of advanced glycation end-products and protein kinase C, have been tested to a limited extent in humans. A small number of randomized controlled human trials of these agents have used surrogate markers such as proteinuria as end points rather than hard end points such as end-stage renal disease or doubling of serum creatinine level. Emerging therapies that specifically target and reverse pathological hallmarks of CKD such as inflammation, fibrosis and atrophy are needed to reduce the burden of this chronic disease and its associated morbidity. This Review examines the evidence for emerging pharmacological strategies for slowing the progression of CKD.

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.

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.

Rosuvastatin protects against podocyte apoptosis in vitro

BACKGROUND

Clinical studies suggest that statins reduce proteinuria and slow the decline in kidney function in chronic kidney disease. Given a rich literature identifying podocyte apoptosis as an early step in the pathophysiological progression to proteinuria and glomerulosclerosis, we hypothesized that rosuvastatin protects podocytes from undergoing apoptosis. Regarding a potential mechanism, our lab has shown that the cell cycle protein, p21, has a prosurvial role in podocytes and there is literature showing statins upregulate p21 in other renal cells. Therefore, we queried whether rosuvastatin is prosurvival in podocytes through a p21-dependent pathway.

METHODS

Two independent apoptotic triggers, puromycin aminonucleoside (PA) and adriamycin (ADR), were used to induce apoptosis in p21 +/+ and p21 -/- conditionally immortalized mouse podocytes with or without pre-exposure to rosuvastatin. Apoptosis was measured by two methods: Hoechst 33342 staining and fluorescence-activated cell sorting (FACS). To establish a role for p21, p21 levels were measured by western blotting following rosuvastatin exposure and p21 was stably transduced into p21 -/- mouse podocytes.

RESULTS

Rosuvastatin protects against ADR- and PA-induced apoptosis in podocytes. Further, exposure to rosuvastatin increases p21 levels in podocytes in vitro. ADR induces apoptosis in p21 -/- mouse podocytes, but rosuvastatin's protective effect is not seen in the absence of p21. Reconstituting p21 in p21 -/- podocytes restores rosuvastatin's prosurvival effect.

CONCLUSION

Rosuvastatin is prosurvival in injured podocytes. Rosuvastatin exerts its protective effect through a p21-dependent antiapoptotic pathway. These findings suggest that statins decrease proteinuria by protecting against podocyte apoptosis and subsequent podocyte depopulation.

Simvastatin abates development of renal fibrosis in experimental renovascular disease

BACKGROUND AND OBJECTIVES

Epithelial-to-mesenchymal transition contributes to renal fibrogenesis, which is regulated by profibrogenic and antifibrogenic mediators. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors can prevent epithelial-to-mesenchymal transition in some models. Therefore, we tested the hypothesis that epithelial-to-mesenchymal transition participates in renal injury in porcine atherosclerotic renovascular disease and can be attenuated by simvastatin.

METHODS

Renal hemodynamics, function, and endothelial function were quantified in vivo in pigs after 12 weeks of combined hypercholesterolemia + renal artery stenosis without (n = 8) or with oral simvastatin supplementation (1.2 mg/kg, n = 6), and in controls (n = 8). Ex-vivo studies assessed renal immunoreactivity to fibrogenic factors and renal histology.

RESULTS

Blood pressure, cholesterol levels, and basal renal function were similar in treated and untreated pigs with hypercholesterolemia + renal artery stenosis. Hypercholesterolemia + renal artery stenosis significantly upregulated renal transforming growth factor-beta signaling and elicited epithelial-to-mesenchymal transition, accompanied by glomerulosclerosis and renal fibrosis. Simvastatin did not affect smad 2/3 expression but upregulated expression of hepatocyte growth factor, bone morphogenetic factor-7, and smad 7 and prevented most of these renal structural and functional alterations. Furthermore, simvastatin improved renal blood flow response to endothelium-dependent challenge (+111.3 +/- 35.5 vs. -30.4 +/- 18.7 ml/min in untreated pigs, P < 0.05).

CONCLUSION

Simvastatin upregulates inhibitors of transforming growth factor-beta signaling, attenuates epithelial-to-mesenchymal transition, and decreases renal fibrosis in hypercholesterolemia + renal artery stenosis. These lipid-lowering-independent effects result in improvement of renal function, suggesting clinically valuable potential for statins in preserving the stenotic kidney and limiting deterioration of renal function in atherosclerotic renovascular disease.

Progression of kidney disease in moderately hypercholesterolemic, hypertensive patients randomized to pravastatin versus usual care: a report from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

BACKGROUND

Dyslipidemia is common in patients with chronic kidney disease. The role of statin therapy in the progression of kidney disease is unclear.

STUDY DESIGN

Prospective randomized clinical trial, post hoc analyses.

SETTING & PARTICIPANTS

10,060 participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (lipid-lowering component) stratified by baseline estimated glomerular filtration rate (eGFR): less than 60, 60 to 89, and 90 or greater mL/min/1.73 m(2). Mean follow-up was 4.8 years.

INTERVENTION

Randomized; pravastatin, 40 mg/d, or usual care.

OUTCOMES & MEASUREMENTS

Total, high-density lipoprotein, and low-density lipoprotein cholesterol; end-stage renal disease (ESRD), eGFR.

RESULTS

Through year 6, total cholesterol levels decreased in the pravastatin (-20.7%) and usual-care groups (-11.2%). No significant differences were seen between groups for rates of ESRD (1.36 v 1.45/100 patient-years; P = 0.9), composite end points of ESRD and 50% or 25% decrease in eGFR, or rate of change in eGFR. Findings were consistent across eGFR strata. In patients with eGFR of 90 mL/min/1.73 m(2) or greater, the pravastatin arm tended to have a higher eGFR.

LIMITATIONS

Proteinuria data unavailable, post hoc analyses, unconfirmed validity of the Modification of Diet in Renal Disease Study equation in normal eGFR range, statin drop-in rate in usual-care group with small cholesterol differential between groups.

CONCLUSIONS

In hypertensive patients with moderate dyslipidemia and decreased eGFR, pravastatin was not superior to usual care in preventing clinical renal outcomes. This was consistent across the strata of baseline eGFR. However, benefit from statin therapy may depend on the degree of the cholesterol level decrease achieved.

Repression of BK virus infection of human renal proximal tubular epithelial cells by pravastatin

BACKGROUND

BK virus (BKV), a human polyomavirus, causes BKV nephritis, which often leads to graft loss after renal transplantation. Currently, the only efficient therapy against BKV nephritis seems to be a reduction or change of immunosuppressive agents, but this may increase the inherent risk of rejection. Here, we report the ability of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitor (statin), which is routinely used to treat hypercholesterolemia, to repress BKV entry pathways in human renal proximal tubular epithelial cells (HRPTEC) and, correspondently, prevent BKV infection.

METHODS

HRPTEC were co-incubated with BKV and pravastatin. Then the percentage of HRPTEC infected with BKV by immunofluorescent analysis and large T-antigen expression which suggested BKV infection by Western blots was assessed in the absence and presence of pravastatin. The distribution of purified and labeled BKV particles in the presence and absence of pravastatin was also investigated.

RESULTS

Both the percentage of BKV infected cells and the large T-antigen expression were significantly decreased in HRPTEC pretreated and co-incubated with pravastatin. However, when pravastatin was added 72 hr after BKV infection it failed to decrease percentage of BKV infected cells. It is likely, that pravastatin's inhibitory effect is explained by depletion of caveolin-1, a critical element of caveolae. BKV enters HRPTEC by caveolar-mediated endocytosis. We provide evidence that pravastatin dramatically decreased caveolin-1 expression in HRPTEC and interfered with internalization of labeled BKV particles.

CONCLUSIONS

Our data suggest that pravastatin, acting through depletion of caveolin-1, prevented caveolar-dependent BKV internalization and repressed BKV infection of HRPTEC.

Chronic kidney disease as a cardiovascular risk state and considerations for the use of statins

Chronic kidney disease (CKD) creates one of the highest risk atherosclerotic states that can occur in human beings. The use of 3-hydroxy-3-methylglutaryl coenzyme reductase inhibitors (statins) has gained widespread acceptance in the general population for the purposes of lowering low-density lipoprotein cholesterol (LDL-C) and reducing the future risks of myocardial infarction, stroke, and cardiac death. In patients with CKD, the balance of benefits and risks of statins appears to be different than that in the general population. Reductions in LDL-C with statins may be associated with a reduced progression of CKD. Importantly, recent studies suggest statins are associated with a reduction in rates of acute kidney injury, mediated by ischemic insults and oxidative stress, after cardiac surgery and exposure to iodinated contrast. A reduction in cardiovascular events with LDL-C reduction in CKD and dialysis patients is yet to be proven. In addition, studies suggest that there are higher adverse drug effects with statins in CKD. This work will address the benefits and risks of this important treatment option for the growing population of patients with CKD, who have not undergone renal transplantation, and are at very high risk of cardiovascular events.

Renoprotection by statins is linked to a decrease in renal oxidative stress, TGF-beta, and fibronectin with concomitant increase in nitric oxide bioavailability

Clinical and experimental studies have provided evidence suggesting that statins exert renoprotective effects. To investigate the mechanisms by which statins may exert renoprotection, we utilized the hypertensive Dahl salt-sensitive (DS) rat model, which manifests cardiovascular and renal injury linked to increased angiotensin II-dependent activation of NADPH oxidase and decreased nitric oxide (NO) bioavailability. DS rats given high salt diet (4% NaCl) for 10 wk exhibited hypertension [systolic blood pressure (SBP) 200 +/- 8 vs. 150 +/- 2 mmHg in normal salt diet (0.5% NaCl), P < 0.05], glomerulosclerosis, and proteinuria (158%). This was associated with increased renal oxidative stress demonstrated by urinary 8-F(2alpha)-isoprostane excretion and NADPH oxidase activity, increased protein expression of transforming growth factor (TGF)-beta (63%) and fibronectin (181%), increased mRNA expression of the proinflammatory molecules monocyte chemoattractant protein-1 (MCP-1) and lectin-like oxidized LDL receptor-1 (LOX-1), as well as downregulation of endothelial NO synthase (eNOS) activity (-44%) and protein expression. Return to normal salt had no effect on SBP or any of the measured parameters. Atorvastatin (30 mg.kg(-1).day(-1)) significantly attenuated proteinuria and glomerulosclerosis and normalized renal oxidative stress, TGF-beta1, fibronectin, MCP-1 and LOX-1 expression, and eNOS activity and expression. Atorvastatin-treated rats showed a modest reduction in SBP that remained in the hypertensive range (174 +/- 8 mmHg). Atorvastatin combined with removal of high salt normalized SBP and proteinuria. These findings suggest that statins mitigate hypertensive renal injury by restoring the balance among NO, TGF-beta1, and oxidative stress and explain the added renoprotective effects observed in clinical studies using statins in addition to inhibitors of the renin-angiotensin system.

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.

Circulating cholesterol as a modulator of risk for renal injury in patients with type 2 diabetes

Amelioration of albuminuria may be related to specific constellations of risk factors including race and dyslipidaemia. Circulating cholesterol could mitigate the beneficial effect of antihypertensive therapy. We assessed whether cholesterol affected the remission of urinary albumin in patients with type 2 diabetes of white, Caucasian and non-white origin. We studied 100 patients (African and Asian: n=57 and Caucasian: n=43) with type 2 diabetes and newly diagnosed microalbuminuria who received intensified and structured care for a median (IQ range) of 41 (32-48) months. Microalbuminuria remitted in 20% and progressed in 12% of patients. In those with uncontrolled systolic hypertension (>140 mmHg) systolic blood pressure fell by a mean (95% CI) of -9.4 (-3.8 to -15.11)mmHg; p=0.002. The change in urinary albumin excretion with time varied inversely with baseline systolic blood pressure (r=-0.25; p=0.04). At 3 years follow-up the decrement in blood pressure was significant for those patients in the regression group (-19.6[16.8]mmHg; p=0.005). In patients of African origin, systolic blood pressure was higher than in the other groups and correlated with cholesterol concentrations (r=0.44; p=0.04). Baseline systolic blood pressure and total cholesterol (odds ratio [95%CI]) were independent determinants of remission and progression of microalbuminuria (1.04[1.006-1.064]; p=0.02 and 1.75[1.03-2.95]; p=0.04). Patients with higher total cholesterol and baseline urinary albumin excretion were less likely to go into remission. Blood pressure correlated with cholesterol concentrations in patients of African origin. Specific cholesterol lowering strategies may benefit certain patients groups at high risk of renal disease.

Hyperlipidemia is associated with accelerated chronic kidney disease progression after lung transplantation

Hyperlipidemia is associated with faster progression of chronic kidney disease (CKD) in the general public. We sought to investigate this association after lung transplantation. Data was retrospectively collected on 230 lung recipients transplanted between January 1997 and December 2003. Estimated glomerular filtration rates (eGFR) and lipid levels were recorded at regular intervals posttransplant. Independent associations between lipid levels early posttransplant and pertinent renal endpoints were investigated. Baseline LDL was 110 +/- 35 mg/dL and remained unchanged at 6 months. A faster decline in eGFR was seen in those with 6 month LDLs > versus < the mean level of 110 mg/dL (p = 0.05). By 6 months posttransplant eGFRs were lower in the 6 month LDL > versus < 110 mg/dL group (53 +/- 23 vs. 62 +/- 29 mL/min/1.73 m2, p = 0.01), a difference that persisted at 60 months (39 +/- 24 vs. 73 +/- 57 mL/min/1.73 m2, p = 0.05). On univariate analysis, a 6 month LDL in the highest quartile, i.e. >140 mg/dL, predicted faster progression to CKD, defined as declining to an eGFR < 30 mL/min/1.73 m2 (HR 1.5, p = 0.01). This finding persisted in the multivariate Cox-proportional model (HR 1.4, p = 0.02). Hyperlipidemia predicts faster decline in renal function after lung transplant. Prospective trials are needed to confirm this finding.

Acute renal failure and myalgia in a transplant patient

A 64-yr-old man with kidney transplant for ESRD as a result of diabetic nephropathy presented with acute renal failure, weakness, myalgia, and pigmented urine. His medications included mycophenolate, cyclosporine, prednisone, furosemide, diltiazem, aspirin, simvastatin, an angiotensin receptor blocker, and insulin. A renal biopsy was performed. Pathologic findings and differential diagnosis are discussed, and the literature is reviewed.

Analysis of antihypertensive effects of statins

Hypertension and hyperlipidemia, two powerful risk factors of cardiovascular disease (CVD), often coexist. Therefore, treatment should consider the beneficial properties of drugs used to treat either condition. Statins, the mainstay of lipid-lowering therapy, result in a significant clinical benefit both in primary and secondary CVD prevention. In addition to their hypolipidemic capacity, other properties may contribute to statin-induced benefits. Clinical and experimental evidence indicates that statins may modulate blood pressure (BP). The mechanisms by which statins reduce BP seem to be largely independent of their lipid effects. Although small, reductions in BP are possibly clinically relevant. Large landmark studies confirm that statins can reduce CVD risk in hypertensive patients. These findings suggest that statins could be prescribed as an adjunct in treating hypertension with dyslipidemia or even in patients with "normal" cholesterol levels. Whether the effect of statins on BP is accompanied by an additional decrease in clinical outcomes needs to be investigated in long-term, large-scale trials.

The effect of statins on preservation of kidney function in patients with coronary artery disease

PURPOSE OF REVIEW

This paper outlines evidence for the putative renal benefits of statins in people with vascular disease.

RECENT FINDINGS

The Greek Atorvastatin and Coronary Heart Disease study showed a modest improvement in kidney function over 4 years among 800 atorvastatin recipients (12%), significantly better than the decrease in kidney function (4%) in 800 placebo recipients. A secondary analysis of the Cholesterol and Recurrent Events trial suggested that pravastatin reduced the rate of kidney function loss to a greater extent in participants with dipstick-positive proteinuria (P < 0.001) and lower levels of renal function at baseline (P = 0.04). A larger post-hoc analysis from this group found that pravastatin modestly reduced the risk of acute renal failure (RR 0.60, 95% CI 0.41-0.86), but not the risk of a 25% decline in kidney function from baseline (RR 0.94, 95% CI 0.88-1.01). In the group with lower baseline kidney function (glomerular filtration rate <60 ml/min/1.73 m(2)) and proteinuria on dipstick urinalysis (n = 249), pravastatin recipients were less likely to experience a 25% or greater decrease in glomerular filtration rate (12.5% versus 19.9%) or acute renal failure (3.2% versus 8.7%).

SUMMARY

Statins may reduce the rate of kidney function loss in people with cardiovascular disease, although the clinical significance of this effect is unclear. Future studies are required before statins can be recommended solely to protect renal function.

Effect of Atorvastatin on Cognitive Function in Patients from the Lipid Lowering and Onset of Renal Disease (LORD) Trial

STUDY OBJECTIVE

To examine the effect of atorvastatin on cognitive function by testing two hypotheses: that atorvastatin 10 mg/day would impair cognitive function, and that other biochemical and demographic measures would better predict cognitive performance than atorvastatin alone.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

Two primary acute care settings in the north and northwest of Tasmania, Australia.

PATIENTS

Fifty-seven patients from the Lipid Lowering and Onset of Renal Disease (LORD) trial.

INTERVENTION

Participants were randomly assigned to receive either atorvastatin 10 mg/day or matching placebo. Cognitive testing was performed in two sessions occurring 12 weeks apart and involved three repeated measures of attention and concentration.

MEASUREMENTS AND MAIN RESULTS

Performance was measured using three standard neuropsychological tests: Digit Symbol Coding subtest, Trail Making Test, and Stroop Color-Word Reading Test. Patients received atorvastatin for a mean of 72.93 weeks and placebo for a mean of 68.85 weeks. Repeated-measures multivariate analysis of variance failed to identify any significant differences between the two groups on any of the three cognitive measures. Multiple regression analyses identified no single factor or combination of plasma cholesterol levels, renal function, liver function, or age that predicted cognitive performance in either the atorvastatin or placebo group on the three measures at either testing session.

CONCLUSION

Atorvastatin 10 mg/day did not produce decrements to cognitive performance. In addition, biochemical and demographic measures and the receipt of atorvastatin versus placebo did not individually or in combination predict cognitive performance on measures of attention and concentration.

The dyslipidemia of chronic renal disease: effects of statin therapy

PURPOSE OF REVIEW

Dyslipidemia is a prevalent condition in patients with chronic renal disease, but is often left untreated. Statin treatment constitutes an effective way to improve lipid abnormalities. This review summarizes present studies on dyslipidemia and its treatment in patients with chronic renal disease.

RECENT FINDINGS

The specific dyslipidemia in renal disease is associated with the presence of proteinuria and decreased creatinine clearance, and may even adversely affect the progression of chronic renal disease. Statin therapy may have renoprotective effects due to a combination of lipid lowering and pleiotropic effects. Statins exert several anti-inflammatory properties and lead to a decrease of proteinuria. Post-hoc analyses of large-scale lipid lowering trials have shown that the reduction of cardiovascular risk was equivalent to the reduction achieved in patients without chronic renal failure. We feel, however, that if intervention with statins is postponed until patients reach end-stage renal disease, statins have limited benefit.

SUMMARY

Present studies suggest that patients with renal disease should be screened early for dyslipidemia and that statins have to be considered as the lipid lowering therapy of choice. These drugs reduce cardiovascular risk. Further studies are needed to firmly establish whether statins preserve renal function.

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.

Association of race, heart failure and chronic kidney disease

Heart failure and kidney disease are two important emerging epidemics. The importance of pre-end stage kidney disease was introduced in the 2002 publication of the National Kidney Foundation's Chronic Kidney Disease Guidelines. One in nine US adults has some degree of kidney disease, many of whom also have heart failure. Among all patients with heart failure, approximately half have significant kidney disease. The distribution of etiologies of these conditions varies among races; blacks tend to have heart and kidney disease predominantly due to hypertension, while whites tend to be affected by ischemic heart disease and Hispanics by diabetic kidney disease. The burden of disease is disproportionately borne by minorities, the cause of which remains to be fully elucidated. The bulk of knowledge of these diseases is based on studies involving predominantly white subjects. Recent studies have suggested that there are racial differences in patients' responsiveness to various classes of drugs. Designs of future studies should take into account these differences.

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.