Statins and renal function

The Association Between Statin Use and Risk of Chronic Kidney Disease in Community-Dwelling Older People in Shanghai, China

Purpose

The effects of statins on renal outcomes have already been studied in patients with chronic kidney disease (CKD); however, data on the general population are limited. We evaluated the association between statin use and risk of CKD in community-dwelling older people in Shanghai, China.

Patients and Methods

This registry-based cohort study was conducted in four communities in four districts in Shanghai. Participants with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² in 2016 were eligible for the study, and new-onset CKD in 2017, 2018, and 2019 was recorded. Poisson generalized linear models were conducted to examine the relationships among statin therapy, dyslipidemia, and CKD; linear mixed-effects models were conducted to examine the relationships between statin therapy and changes in eGFR. All analyses were performed with both conventional adjustment and propensity score-matching methods.

Results

Of the study cohort of 2455 participants (41.1% men; average age, 68.06 years), 624 (25.4%) were treated with stains. Two propensity score-matched cohorts of 604 participants each were analyzed (statin users and nonusers). Statin use was significantly associated with a decreased risk of new-onset CKD with hazard ratios (HRs) and 95% confidence intervals (CIs) of 0.73 (0.59 to 0.91) (p<0.01) in the unmatched cohort and 0.75 (0.59 to 0.97) (p=0.02) in the matched cohort. There were significant differences in the eGFR decline between statin users and nonusers from baseline to 3 years in the unmatched and matched cohorts (both p<0.05). In addition, both statin users and nonusers with dyslipidemia experienced more new-onset CKD (both p<0.05).

Conclusion

Statin use was significantly associated with a decreased risk of new-onset CKD and a slower decline in eGFR in community-dwelling older people. Meanwhile, dyslipidemia was a risk factor for CKD progression among both statin users and nonusers.

Contrast-induced nephropathy in non-cardiac vascular procedures, a narrative review: Part 2

This is Part 2 of a narrative review summarizing the literature on CIN after non-cardiac vascular diagnostic or therapeutic procedures, focusing on peripheral artery disease (PAD) and renal artery stenosis (RAS). Part 1 discussed CIN in relation to aortic aneurysms and carotid stenosis. We comment on the incidence, biomarkers, risk factors, and consequences of CIN in patients with PAD or RAS, as well as on strategies to prevent CIN. Future perspectives in the field of CIN in relation to non-cardiac vascular procedures are also considered.

The renoprotective effects of simvastatin and atorvastatin in patients with acute coronary syndrome undergoing percutaneous coronary intervention: An observational study

Some statins, such as atorvastatin, have proven renoprotective effects. The comparative renoprotective potential of simvastatin is less clear. This study aimed to compare the renoprotective effects of simvastatin with atorvastatin in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). This observational study examined the medical records of 271 patients who were treated at the Guangdong Cardiovascular Institute from April 2004 to February 2008. Patients had received either 40 mg simvastatin (n = 128) or 20 mg atorvastatin (n = 143), daily, for a period of at least 6 months following PCI. Declined renal function (DRF) was defined at the occurrence of chronic kidney disease (CKD) or elevated CKD stages at 6-months post-PCI. Results showed that the incidence of DRF was similar among patients taking simvastatin or atorvastatin (25.00% vs 26.57%, respectively). Kaplan-Meier survival analysis showed that patients who developed DRF had a higher incidence of mortality and major adverse cardiovascular events (MACEs) than those without DRF (17.41% vs 28.57%, P = .0308). Multivariate logistic regression analysis identified diabetes and baseline estimated glomerular filtration rate as independent risk factors for DRF. Collectively, our results indicate that simvastatin has comparable renoprotective effects to atorvastatin in ACS patients undergoing PCI. Further studies are warranted to confirm the comparative renoprotective effects of statins.

Dyslipoproteinemia and Peripheral Arterial Occlusive Disease

Peripheral arterial occlusive disease (PAOD) is common in older age. PAOD is associated with an increased risk of vascular events (eg, myocardial infarction or stroke). Therefore, the prevention and treatment of PAOD is important, especially at a time when the elderly population is increasing. There is an association between lipid abnormalities and the risk of developing PAOD. However, it is not yet definitively established that early intervention with lipid-lowering drugs prevents the development of PAOD. There is evidence that vascular events in patients with PAOD can be significantly reduced by statins and that the symptoms associated with PAOD are improved by this treatment. There is an urgent need for appropriately designed lipid-lowering trials in patients with PAOD.

Short-term Lipid-Lowering Treatment with Atorvastatin Improves Renal Function But Not Renal Blood Flow Indices in Patients with Peripheral Arterial Disease

Some studies have suggested that lipid lowering with statins exerts favorable effects on the progression of chronic kidney disease. Therefore, the authors assessed the effects of short-term atorvastatin treatment on biochemical markers of renal function and evaluated duplex indices of renal blood flow (RBF) in patients with peripheral arterial disease. Hyperlipidemic claudicants (n=18), aged 44-85 years, were treated for 8 weeks with 20 mg/day atorvastatin. Blood tests at baseline and after 8 weeks included serum fasting lipids, creatinine, urate, and cystatin C (a sensitive indicator of renal function) levels. RBF was also assessed (n=9) by measuring pulsatile and resistance duplex indices. As expected, there was a significant improvement in total cholesterol, low-density lipoprotein cholesterol, and triglycerides. There was also a significant (p<0.0001) fall in serum creatinine from 89 (58-125) to 79 µmol/L (54-119) and an increase in calculated creatinine clearance (CrCl) from 72 (40-129) to 80 mL/minute (47-138; p<0.0001). Serum cystatin C values decreased significantly (p=0.0002) from 1.04 (0.57-1.56) to 0.90 mg/L (0.47-1.47). There were no detectable changes in the RBF duplex indices. Treatment of stable claudicants with atorvastatin for 8 weeks was associated with improved renal function (as assessed by serum creatinine, cystatin C, and calculated CrCl) without changes in RBF. Further studies are required to identify the mechanisms involved in this phenomenon.

Risk Modification in Patients with Peripheral Arterial Disease: A Retrospective Survey

Peripheral arterial disease (PAD) is underdiagnosed and undertreated. This is despite the high vascular morbidity and mortality rates associated with PAD. There is also evidence that quitting smoking, improving the lipid profile, lowering the blood pressure, and administering antiplatelet drugs reduce the risk of vascular events in these patients. Secondary prevention for patients with PAD is yet to meet the standard of care for those with ischemic heart disease. The authors surveyed 200 claudicants attending a vascular clinic with additional follow-up in a risk modification clinic. After a median follow-up of 28 months (range: 6-65) there was a significant (p=0.001) improvement in walking distance; 34 patients (17%) had a vascular ischemic event. Of those, 11 patients (5.5%) had worsening intermittent claudication and 9 had a stroke/transient ischemic attack; 9 events (4.5%) were fatal. The lipid targets were met in 76% the patients. Half the smokers quit smoking and 94% of the patients were taking antiplatelet drugs or anticoagulants. Blood pressure reached the accepted target in 87% of the patients. Secondary prevention in patients with PAD may reduce the risk of vascular events. Aggressive risk modification is therefore recommended.

Secondary Prevention of Ischemic Cerebrovascular Disease. What Is the Evidence?

Patients who had a transient ischemic attack or stroke are at increased risk of experiencing recurrent cerebrovascular events. For this reason, secondary prevention of ischemic cerebrovascular disease is essential. Several modifiable, lifestyle-associated risk factors have been implicated, such as physical activity, smoking, and alcohol consumption. Established and emerging vascular risk factors are associated with an increased risk of stroke. Pharmacologic treatment, including the use of antiplatelet, antihypertensive, and lipid-lowering agents, has also been shown to reduce the risk of secondary cerebrovascular events. Surgical intervention, either open or endovascular, may be the preferred therapeutic option in well-defined subsets of patients. It is important to establish specific measures for the early detection and prevention of recurrent cerebrovascular disease. Therefore, further research and greater awareness in this field are needed.

Starting with Rosuvastatin in Primary Hyperlipidemia—

The authors investigated the effects of rosuvastatin, beyond its lipid-lowering activity, on several nonlipid metabolic variables, along with its safety and tolerability, in patients treated for primary hyperlipidemia. Patients (n=55) with primary hyperlipidemia were open-label assigned to the recommended starting dose of rosuvastatin 10 mg/day, and serum metabolic variables were measured at baseline and after 8 and 20 weeks. Treatment with rosuvastatin produced significant reductions in total cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein B, nonhigh-density lipoprotein cholesterol (non HDL-C), and triglyceride concentrations, whereas HDL-C, apolipoprotein A-I, and lipoprotein(a) levels did not change significantly from baseline. The LDL-C treatment target was achieved in 71% of patients. No significant variations in renal function parameters (serum creatinine and creatinine clearance), insulin resistance estimates, and serum concentrations of uric acid, total homocysteine, vitamin B12, and folic acid were observed during the period of treatment. High-sensitivity C-reactive protein levels were significantly lowered by rosuvastatin therapy (median values, 3.1 vs 2.0 vs 1.9 mg/L, at 0, 8, and 20 weeks, respectively; p<0.0001). In conclusion, rosuvastatin at 10 mg/day is a highly effective, safe, and well-tolerated monotherapy option for patients with primary hyperlipidemia, with a favorable antiinflammatory potential and nondeteriorating effects on renal function.

The Effect of Short-Term Treatment with Simvastatin on Renal Function in Patients with Peripheral Arterial Disease

The objective of this study was to investigate the effects of lipid-lowering treatment on renal function in patients with peripheral arterial disease (PAD). This was a retrospective study of hyperlipidemic claudicants referred to a vascular surgery and risk modification clinic. Serum creatinine and urate concentrations and the fasting lipid profile were measured pretreatment and after 3-4 months of treatment with 20 mg/day simvastatin. In 103 consecutive patients with PAD (57 men; 46 women), median age 67 years (range: 51 to 83) there was a significant decrease in serum creatinine from a mean (SD) of 87 (12) μmol/L pretreatment to 84 (12) μmol/L post-treatment (p<0.0001). This difference was more marked in the tertile of patients with the highest baseline creatinine levels. There was also a significant reduction in serum urate from 0.37 (0.07) mmol/L to 0.35 (0.07) mmol/L (p<0.0001). Both these effects were independent of the degree of total cholesterol (TC) or low-density lipoprotein (LDL) cholesterol reduction. There was a significant reduction in TC from 6.6 (1.0) to 5.2 (0.8) mmol/L and LDL cholesterol from 4.3 (1.0) to 2.8 (0.7) mmol/L; both p<0.0001. Significant improvement also occurred in the high-density lipoprotein cholesterol and triglyceride levels. Cholesterol lowering with simvas tatin 20 mg/day improved indices of renal function after 3-4 months of treatment in hyper lipidemic patients with PAD. Further studies are needed to establish and define the clinical relevance of these findings, especially in patients with different degrees of renal failure.

The Degree of Albuminuria Is Related to Left Ventricular Hypertrophy in Hypertensive Diabetics and Is Associated with Abnormal Left Ventricular Filling: A Pilot Study

The association of albuminuria and left ventricular (LV) hypertrophy (LVH) in diabetics aggra vates the prognosis. The authors studied the relation between LVH and the degree of albu minuria in diabetics and investigated the relationship of albuminuria to LV filling. A comparison was made between 30 hypertensive diabetics, 10 of whom had microalbuminuria (MIC) and 20 had macroalbuminuria (MAC), and 18 diabetics who were normotensive and normalbuminuric (NOR). LV mass index (LVMI) and LV ejection fraction (LVEF) were measured during echocar diography. LV filling pattern at rest and at peak standardized isometric exercise (IME) using handgrip was assessed by measuring E/A (peak velocity of the early/atrial filling waves) of the transmitral flow during Doppler and echocardiography. Each patient underwent a stress ECG test. LVMI was higher in MAC (132.3 ±55.4) than in MIC (115.6 ±32.5) or NOR (90.0 ±31.8) (p<0.01). There were more patients in MAC with LVH (n = 13) and abnormal filling (n = 9 at rest and 16 with IME) than in MIC (LVH = 5, abnormal filling = 1 at rest and 10 during IME) or NOR (LVH = 3, abnormal filling = 1 at rest and 9 during IME) (p < 0.02). LVMI was not related to LVEF. Although blood pressure was not different between MAC and MIC groups, it was signif icantly higher than in the NOR group. This study suggests that a high degree of albuminuria in hypertensive diabetics is associated with greater value for LVMI and an increased incidence of LVH independent of blood pressure level or systolic LV function. LVH is associated with abnormal LV filling. The degree of albuminuria may predict LVMI and LVH, which are associated with abnormal LV filling. This association of abnormal LV filling with albuminuria in hypertensive diabetic patients may account for their high risk of cardiovascular events.

Lipid abnormalities in kidney disease and management strategies

Patients with kidney diseases continue to experience significant cardiovascular disease (CVD) morbidity and mortality. Although there are many important risk factors playing a role in the pathogenesis of CVD in chronic kidney disease (CKD) patients, dyslipidemia (elevated triglycerides, elevated oxidized low-density lipoprotein and low/dysfunctional low high-density) represents one of the modifiable risk factors. Renal failure patients have unique lipid abnormalities which not only have complex role in pathogenesis of CVD but also cause relative resistance to usual interventions. Most of the randomized trials have been in hemodialysis population and data from CKD non-dialysis, peritoneal dialysis and renal transplant populations is extremely limited. Compared to general population, evidence of mortality benefit of lipid lowering medications in CKD population is scarce. Future research should be directed towards establishing long term benefits and side effects of lipid lowering medications, through randomized trials, in CKD population.

Risks and benefits of statin use in young people with type 1 diabetes

Cardiovascular disease (CVD) is the primary cause of mortality in patients with type 1 diabetes (T1D). Despite advances in the management of microvascular complications of T1D, there is a lack of similar progress in reduction of macrovascular complications. Dyslipidemia is one of the major contributory factors for macrovascular complications in T1D, but the literature suggests significant under-treatment of this risk factor in children and adolescents with diabetes. Statins have shown to be both effective and safe in young people with familial hypercholesterolemia and adults with diabetes mellitus, but the role for statins in children and adolescent with T1D remains unclear and controversial. In this review, we will summarize the risks and benefits of statin use in young people with T1D.

Effect of simvastatin on plasma homocysteine levels and its modification by MTHFR C677T polymorphism in Chinese patients with primary hyperlipidemia

OBJECTIVE

We investigate the effect of simvastatin on plasma homocysteine (Hcy) levels and whether genetic factor affects the effect of simvastatin.

METHODS

A total of 338 patients with hyperlipidemia were enrolled. Simvastatin was orally administered at a dose of 20 mg/day for 8 weeks. Plasma Hcy levels were measured by high-performance liquid chromatography at baseline and after 8 weeks of treatment. Genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism was performed by TaqMan probe technique.

RESULTS

Serum total Hcy levels were positively correlated with serum creatinine (r = 0.332, P < 0.001). Among total subjects, simvastatin treatment resulted in a significant reduction in serum Hcy levels after 8 weeks (-0.37 ± 2.21 μmol/L, P = 0.003), and this effect was dependent on the initial levels of serum Hcy. The individuals with 677TT genotype had a significantly higher baseline Hcy level and a greater change in Hcy levels. After stratification by body mass index (BMI), we observed a significant increase in Hcy levels among the TT genotype group in adjusted model (beta±SE: 2.64 ± 0.84 μmol/L; P = 0.002) among patients with BMI ≥ 25 (kg/m(2) ).

CONCLUSIONS

Simvastatin can cause a marked decrease in plasma Hcy levels. MTHFR C677T genetic variant contributes to simvastatin's effects among Chinese subjects with primary hyperlipidemia.

Clinical profile of long-term survivors and nonsurvivors with type 2 diabetes

OBJECTIVE

To compare clinical profile of long-term survivors and nonsurvivors with type 2 diabetes (T2DM).

RESEARCH DESIGN AND METHODS

After conducting a retrospective survey of >200,000 case records, we identified T2DM survivors (>40 years of duration) and age at diagnosis and sex-matched T2DM nonsurvivors. Prevalence of complications and causes of death were analyzed. Retinopathy was diagnosed by retinal photography. Microalbuminuria and macroalbuminuria, peripheral vascular disease based on ankle-brachial index <0.9, coronary artery disease based on history of myocardial infarction or coronary revascularization, and neuropathy based on vibration perception threshold >20 V were compared in both groups.

RESULTS

The mean duration of diabetes of survivors (n = 238) was 43.7 ± 3.9 years, and that of the nonsurvivors (n = 307), at time of death, was 22.4 ± 11.0 years (P < 0.001). Nonsurvivors had significantly higher systolic and diastolic blood pressures, plasma glucose, HbA1c, serum cholesterol, LDL cholesterol, and triglycerides and lower HDL cholesterol compared with long-term survivors (P < 0.001 for all parameters except systolic blood pressure, which was P = 0.027). Myocardial infarction (46.4%) and renal failure (16.6%) were the most common causes of death. Prevalence of most complications was higher among survivors because of longer duration and older age, as follows, for survivors versus nonsurvivors: retinopathy, 76 vs. 62%; microalbuminuria, 39.1 vs. 27.3%; macroalbuminuria, 8.4 vs. 23.7%; neuropathy, 86.5 vs. 63.5%; peripheral vascular disease, 23.1 vs. 11.4%; and coronary artery disease, 44.5 vs. 40.7%.

CONCLUSIONS

Long-term survivors with T2DM had better glycemic and blood pressure control and more favorable lipid profiles.

Statins in heart failure: do we need another trial?

Statins lower serum cholesterol and are employed for primary and secondary prevention of cardiovascular events. Clinical evidence from observational studies, retrospective data, and post hoc analyses of data from large statin trials in various cardiovascular conditions, as well as small scale randomized trials, suggest survival and other outcome benefits for heart failure. Two recent large randomized controlled trials, however, appear to suggest statins do not have beneficial effects in heart failure. In addition to lowering cholesterol, statins are believed to have many pleotropic effects which could possibly influence the pathophysiology of heart failure. Following the two large trials, evidence from recent studies appears to support the use of statins in heart failure. This review discusses the role of statins in the pathophysiology of heart failure, current evidence for statin use in heart failure, and suggests directions for future research.

Association between serum fibroblast growth factor 21 and diabetic nephropathy

Fibroblast growth factor 21 (FGF-21) is a new metabolic regulator with beneficial effects on lipid and glucose metabolism in animal models of diabetes mellitus. The aim of this study was to explore the relationship between FGF-21 and diabetic nephropathy in humans. Serum FGF-21 levels were determined in groups of control (n = 50) and type 2 diabetes mellitus (T2DM) patients with normoalbuminuria (n = 158), microalbuminuria (n = 68), and macroalbuminuria (n = 38) using enzyme-linked immunosorbent assay. Multiple linear regression models were used to analyze the associations between FGF-21 or other biomedical indices and urinary albumin excretion (UAE). Median serum FGF-21 levels were increased in T2DM patients compared with nondiabetic controls and were significantly higher in patients of higher UAE group. In groups of control and T2DM patients with normoalbuminuria, microalbuminuria, and macroalbuminuria, median serum (interquartile range) FGF-21 levels were 467.89 (294.59-519.56), 492.30 (354.59-640.42), 595.01 (480.49-792.31), and 665.20 (448.68-829.75) ng/L (P < .001), respectively. After adjustment for the confounders, FGF-21, fasting plasma glucose, and high-density lipoprotein cholesterol levels were found to be independently associated with UAE in diabetic patients. Serum FGF-21 level is independently correlated with UAE in T2DM patients, indicating that circulating FGF-21 may be involved in diabetic nephropathy.

Circulatory syndrome: an evolution of the metabolic syndrome concept!

The metabolic syndrome has been a useful, though controversial construct in clinical practice as well as a valuable model in order to understand the interactions of diverse cardiovascular risk factors. However the increasing importance of the circulatory system in particular the endothelium, in both connecting and controlling organ function has underlined the limitations of the metabolic syndrome definition. The proposed "Circulatory Syndrome" is an attempt to refine the metabolic syndrome concept by the addition of recently documented markers of cardiovascular disease including renal impairment, microalbuminuria, arterial stiffness, ventricular dysfunction and anaemia to more classic factors including hypertension, dyslipidemia and abnormal glucose metabolism; all of which easily measured in clinical practice. These markers interact with each other as well as with other factors such as aging, obesity, physical inactivity, diet and smoking. The final common pathways of inflammation, oxidative stress and hypercoagulability thereby lead to endothelial damage and eventually cardiovascular disease. Nevertheless, the Circulatory (MARC) Syndrome, like its predecessor the metabolic syndrome, is only a small step toward an understanding of these complex and as yet poorly understood markers of disease.

Sinvastatina e lesão renal aguda isquêmica em ratos

OBJETIVOS: O estudo visou verificar a ação renoprotetora da sinvastatina em modelo animal de isquemia/reperfusão por 30 minutos. MÉTODOS: A isquemia foi obtida por meio do clampeamento dos pedículos renais bilaterais por 30 minutos, seguida de reperfusão. Ratos Wistar, machos foram usados pesando entre 250-300g, distribuídos nos seguintes grupos: SHAM (controle, sem clampeamento renal); Isquemia (isquemia renal por 30 minutos); Isquemia+Estatina (sinvastatina 0,5 mg/kg, via oral durante três dias). A função renal (clearance de creatinina, método de Jaffé), a osmolalidade urinária, os peróxidos urinários foram avaliados. RESULTADOS: Os resultados mostraram que a estatina melhorou a função renal, a osmolalidade urinária e reduziu a excreção de PU. CONCLUSÃO: Em síntese, o estudo confirmou o efeito renoprotetor da estatina, com ação antioxidante de proteção renal.

Management of transplant renal artery stenosis

End-stage renal disease (ESRD) was universally fatal until dialysis (peritoneal and hemodialysis) and renal transplantation were introduced. However, there are multiple complications associated with transplantation including transplant renal artery stenosis (TRAS). Transplant renal artery stenosis is an important cause of premature renal failure, uncontrolled hypertension, and allograft loss. There are 3 treatment modalities available for TRAS: optimal medical therapy alone, percutaneous intervention, and surgical revascularization both with optimal medical therapy. Percutaneous transluminal angioplasty (PTA) has now become the initial treatment of choice for TRAS. However, there are conflicting data regarding the efficacy of PTA, with growing evidence showing lack of significant benefit in blood pressure (BP) or renal function in patients undergoing PTA versus medical management. However, there have been no randomized control studies that have established the superiority of either method. We review the existing data and analyze management of TRAS as reported in multiple case series including findings from our center.

Atorvastatin protects renal function in the rat with acute unilateral ureteral obstruction

OBJECTIVES

To examine the effects of atorvastatin on renal hemodynamics and urinary microalbumin levels in rats with acute unilateral ureteral obstruction (UUO). Previous studies have demonstrated that treatment with statins attenuated renal structural damages in rodents with chronic UUO. However, it is not known whether statins afford protection of renal function.

METHODS

UUO was created by ligation of the left ureter in rats maintained on a regular diet or the same diet but supplemented with atorvastatin (50 mg/kg/d) for 2 weeks. Renal clearance experiments were performed after release of UUO at 1 hour, 6 hours, or 12 hours.

RESULTS

Atorvastatin treatment lowered plasma triglyceride but not cholesterol levels. Both glomerular filtration rate and effective renal plasma flow were significantly greater in atorvastatintreated rats after release of UUO at 1 hour, 6 hours, and 12 hours. Significant reduction of urinary microalbumin to creatinine ratios occurred in the atorvastatin-treated group at 12 hours but not earlier.

CONCLUSIONS

Atorvastatin treatment affords protection of renal function in acute UUO and reduces urinary microalbumin levels without lowering cholesterol levels. This pleiotropic action of atorvastatin on preservation of renal hemodynamics may be important in attenuating subsequent renal structural injury in chronic UUO.

Are Statins an Option in the Management of Abdominal Aortic Aneurysms?

Medline was searched for studies investigating the perioperative and long-term results that derive from statin use in patients with abdominal aortic aneurysm and the clinical and experimental evidence dealing with aneurysm expansion. Data suggest that statins improve the perioperative and long-term outcomes of aneurysm operations and may also reduce expansion rates. International guidelines recommend the use of statins in these patients because abdominal aortic aneurysms are considered as a coronary heart disease equivalent. These guidelines do not appear to have been widely implemented. Preliminary results suggest that statins might play a role in the management of abdominal aortic aneurysms. Verification of these results in large-scale trials may hold implications for a more comprehensive approach of patients with abdominal aortic aneurysms as well as population-wide aneurysm screening programs. Irrespective of the role of statins on aneurysm expansion rates, it is important to ensure that all abdominal aortic aneurysm patients receive statin therapy to improve perioperative and long-term morbidity and mortality.

Multiorgan-protective actions of blockers of the renin-angiotensin system, statins and erythropoietin: common pleiotropic effects in reno-, cardio- and neuroprotection

Renal diseases induce nephroprotective measures that may affect the heart, brain and other organs. In addition, many cardiovascular and neurological diseases are accompanied by renal lesions. For these reasons, multiorgan-protective measures, including cardio-, reno- and neuro-protective measures, are necessary to treat these diseases. The drugs used in nephrology are often pleiotropic. Although they usually address a single organ or tissue, many of them have complex actions that may provide multiorgan-protection. The present paper aims to review 3 classes of drugs that are commonly prescribed in nephrological practice: statins, RAS blockers (such as ACEIs and ARBs) and erythropoietin (EPO). This paper highlights the renoprotective actions, as well as those that are protective of the heart, brain and other organs, of these drugs at the cellular and molecular level. Their protective actions are attributable to their main effects and pleiotropic effects. The protective pleiotropic actions of these drugs may be exerted on multiple organs, making them multiorgan-protective. Another objective is to analyse the shared multiorgan-protective pleiotropic effects of RAS blockers (ACEIs and ARBs), statins and erythropoietin. This will allow for the practical association of the main renoprotective drugs with multiorgan protection.

Should a statin be prescribed to every patient with heart failure?

Chronic heart failure (HF) represents an emerging epidemic since its prevalence is continuously increasing despite advances in treatment. Many recent clinical studies have clearly demonstrated that statin therapy is associated with improved outcomes in HF irrespective of aetiology (ischaemic or not) or baseline cholesterol levels. Indeed, most of the conducted large statin trials and trials in HF have demonstrated a positive effect of statins in HF patients. Furthermore, the use of statins in HF seems to be safe as none of the recent trials has resulted in worse outcomes for HF patients treated with statins. Potential mechanisms through which statins could benefit the failing myocardium include non-sterol effects of statins, as well as effects on nitric oxide and endothelial function, inflammation and adhesion molecules, apoptosis and myocardial remodelling and neurohormonal activation. This review discusses the pathophysiological basis of statin effects on HF and focuses on clinical data for the benefit from statin use in this setting. Until today there are no official recommendations in both the American and the European guidelines regarding the use of statins in HF patients, as the available data come from small observational or larger but retrospective, non-randomised studies. Therefore, HF patients should be treated according to current lipid guidelines. Large randomised clinical trials are underway and will further delineate the role of statin therapy in HF patients. Until more data are available, we could not recommend statin use to every patient with HF irrespective of HF aetiology and baseline cholesterol levels.

Statins: An essential component in the management of carotid artery disease

OBJECTIVE

We aimed to define the role of treatment using statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) in the management of patients with carotid artery disease.

LITERATURE SEARCH METHODS

We searched PubMed for studies evaluating the effect of statins on carotid IMT and the occurrence of cerebrovascular events.

LITERATURE SEARCH RESULTS

Current evidence indicates that routine statin therapy reduces carotid intima-media thickness progression and stroke risk. Additionally, statin treatment significantly reduces perioperative as well as long-term morbidity and mortality in patients undergoing carotid surgery or endovascular interventions. It would also be expected that statins would reduce coronary events in this high-risk population.

CONCLUSIONS

Statins should be considered as an essential component of the therapeutic approach of patients with carotid artery stenosis.

The role of fibrinogen and fibrinolysis in peripheral arterial disease

Peripheral arterial disease (PAD) is associated with high rates of cerebrovascular and cardiovascular events; PAD is a marker of systemic atherosclerosis. As a result, standard therapy for all PAD patients should be directed at both peripheral and systemic atherosclerosis. Modification of established risk factors in the form of smoking cessation, correcting hypertension, optimizing diabetic control and normalizing lipids is essential. Furthermore, novel risk factors have emerged including fibrinogen and other hemostatic factors. Fibrinogen is a coagulation factor and a marker of the acute phase response (inflammation), a platelet activator, a major determinant of plasma viscosity and a component of the atherosclerotic plaque. Fibrinogen appears not only to predict the severity of PAD, but also serves as a marker for future development of PAD. Whether reducing the levels of fibrinogen and other coagulation factors will decrease the incidence and progression of PAD remains to be resolved. This review summarizes the role of fibrinogen in the pathogenesis of PAD and its association with other hemostatic factors. The role of fibrinolysis in patients with PAD is also considered.

The role of established and emerging risk factors in peripheral vascular graft occlusion

Several studies have evaluated the association between established as well as emerging vascular risk factors with peripheral graft occlusion. There is evidence for a link between the risk for graft occlusion and total serum cholesterol, low-density lipoprotein cholesterol and triglyceride levels. The overall effect of smoking shows a 2.35-fold increase in risk of graft failure. Studies involving diabetic patients undergoing peripheral bypass may have failed to detect higher occlusion rates, possibly due to increased morbidity and mortality as well as higher amputation rates even if the graft is patent. Both antiplatelet agents and anticoagulation seem to be effective in the prevention of graft occlusion. Unconvincing data have been published with regards to the effect of hypertension on graft patency. Emerging factors such as fibrinogen, lipoprotein (a), C-reactive protein and homocysteine levels should also be considered when assessing the risk of graft occlusion. More research is needed to prevent graft occlusion due to the obvious clinical relevance, quality of life and cost issues.

Atorvastatin Preserves Renal Function in Chronic Complete Unilateral Ureteral Obstruction

PURPOSE

The pleiotropic effects of hMG-CoA (3-hydroxy-3-metylglutaryl coenzyme A) reductase inhibitors may provide renal protection in chronic kidney disease. We examined whether atorvastatin administration preserved renal function in rats with chronic unilateral ureteral obstruction.

MATERIALS AND METHODS

Renal clearance experiments were performed in sham operated rats and rats subjected to 3 or 12-day unilateral ureteral obstruction. Hemodynamics parameters and urinary microalbumin levels from the obstructed kidney were also measured. The rats were maintained on a regular diet or the same diet but supplemented with atorvastatin (50 mg/kg daily).

RESULTS

Atorvastatin administration did not alter plasma total cholesterol but it significantly decreased triglyceride levels. In sham operated and 3-day unilateral ureteral obstruction rats atorvastatin treatment did not have effects on the glomerular filtration rate or effective renal plasma flow and it also did not affect urinary microalbumin levels. In rats with 12-day unilateral ureteral obstruction the glomerular filtration rate but not effective renal plasma flow was significantly higher and urinary microalbumin was significantly lower in atorvastatin treated rats than in those without atorvastatin treatment.

CONCLUSIONS

Atorvastatin treatment decreased microalbuminuria and helped preserve filtration function in chronic unilateral ureteral obstruction without altering plasma cholesterol levels, suggesting that pleiotropic renal protection is offered by this statin.

Statins Ameliorate Glomerular Permeability Changes in Streptozotocin-Induced Diabetic Rats

AIMS

Statins reduce albumin excretion rate and retard the progression of diabetic nephropathy. Whether statins alter size selectivity of glomerular filtration in diabetic rats is not known.

METHODS

The creatinine clearance and the permeability of glomeruli to a group of fluorescein isothiocyanate dextrans of varying molecular weights were studied in rats with streptozotocin-induced diabetes that were treated with either 10 mg/kg rosuvastatin or simvastatin for 5 weeks.

RESULTS

Statin therapy did not significantly alter the increased creatinine clearance in diabetic rats. During the 5 hours of urine collection there was near-complete filtration of 4-, 10-, and 20-kD dextrans in all rat groups studied. The filtration of 70- and 40-kD dextrans was significantly increased in diabetic rats after 5 weeks of diabetes. Rosuvastatin but not simvastatin was associated with partial normalization of glomerular filtration of the 70- and 40-kD dextrans. Treatment with mevalonate (150 mg/kg in drinking water for 5 weeks) reversed the favorable effects of rosuvastatin on glomerular permeability.

CONCLUSIONS

Statin treatment of rats with streptozotocin-induced diabetes ameliorates glomerular permeability changes. The favorable effect of rosuvastatin is probably related to the inhibition of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, because mevalonate treatment reversed the favorable effects of rosuvastatin.

Smoking and Aortic Diseases

Cigarette smoking is a major vascular risk factor and in this context, it is an independent risk factor for the development of aortic disease, especially the formation and growth of abdominal aortic aneurysms (AAA). Medline was searched up to January 31, 2007 for the relevant literature for this review of the mechanisms by which smoking causes aortic wall damage and its subsequent impact on the clinical manifestation of this process. Idiopathic AAAs and aortic dissection are considered, as well as other aortic diseases (eg, Takayasu, Kawasaki, Behcet and Buerger). There is evidence suggesting an abnormal homeostasis between proteolytic and antiproteolytic activity in the vascular wall during the development of AAAs, and these mechanisms can be influenced by smoking. Smoking cessation plays an important role in the management of aortic disease.

Non-low-density lipoprotein cholesterol-associated actions of ezetimibe: an overview

Ezetimibe, an intestinal cholesterol absorption inhibitor, lowers circulating low-density lipoprotein cholesterol (LDL-C) levels both when administered as monotherapy and in combination with other hypolipidaemic drugs, mostly statins. This review focuses on the effects of ezetimibe on non-LDL-C-associated variables. In most studies, ezetimibe effectively reduced triglyceride and increased high density lipoprotein cholesterol levels. The authors also consider the effect of ezetimibe on other variables such as C-reactive protein levels, insulin sensitivity and endothelial function. Ezetimibe is useful in patients with sitosterolaemia (a rare inherited disorder) as it significantly reduces plasma phytosterol concentrations. Ezetimibe fulfils two of the three essential characteristics of any drug (efficacy and safety). However, clinical studies are required to provide evidence of its ability to reduce vascular events.

Statin-associated adverse effects beyond muscle and liver toxicity

Randomized controlled trials with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have consistently demonstrated significant reductions in cardiovascular morbidity and mortality. Statins are currently the most widely used drugs in many countries. The most important adverse effects are associated with muscle and liver toxicity. However, with increased use and dose of statins and their over-the-counter availability in some countries more cases of other rare side effects may be seen in clinical practice. In the present article we review the literature concerning the statin-related adverse effects other than muscle and liver injury and we provide insight into their clinical relevance and possible underlying mechanisms.

Elevated serum uric acid levels in metabolic syndrome: an active component or an innocent bystander?

Elevated serum uric acid (SUA) levels are commonly seen in patients with the metabolic syndrome (MetS). Several mechanisms, both direct and indirect, connect the increased SUA levels with the established diagnostic criteria of MetS. It is possible that the increased cardiovascular disease risk associated with the MetS is partially attributed to elevated circulating SUA concentration. Several drugs used in the treatment of MetS may alter SUA levels. Thus, lifestyle measures together with the judicious selection of drugs for the treatment of hypertension, dyslipidemia, and insulin resistance associated with MetS may result in a reduction of SUA levels and possibly cardiovascular disease risk. This review summarizes the pathophysiologic association between SUA and MetS and focuses on the prevention of hyperuricemia and its cardiovascular consequences.

Statins: another class of antihypertensive agents?

The assessment of global cardiovascular risk is an essential step in the management of atherosclerotic disease prevention. Among the risk factors to be addressed are hypertension and hyperlipidaemia; these commonly coexist. A neutral or lipid-friendly antihypertensive agent is probably useful in the presence of lipid abnormalities. Similarly, statins have been shown to decrease cardiovascular risk in hypertensive patients. There is also experimental and clinical evidence that statins have blood pressure (BP)-lowering effects. In this review, we discuss the beneficial effects of statins on BP, and provide an overview of the underlying pathophysiology. We also consider the evidence justifying the use of statins in the management of hypertensive patients.

Can Statins Reduce Perioperative Morbidity and Mortality in Patients Undergoing Non-Cardiac Vascular Surgery?

AIMS

To determine whether statins can reduce perioperative morbidity and mortality in patients undergoing non-cardiac vascular surgery.

METHODS

A search using Pubmed was performed to identify reports in English. The search terms were: "statins", "perioperative morbidity", "perioperative mortality" and "vascular surgery". We excluded studies dealing with the effect of statins in cardiac surgery. Retrieved articles were manually searched.

RESULTS

Current evidence shows that statins decrease perioperative morbidity and mortality in patients undergoing non-cardiac vascular surgery. Any benefit probably occurs soon (within a month) after initiating treatment.

CONCLUSIONS

Appropriately designed trials need to confirm the beneficial effect of perioperative statin therapy in various patient categories. The optimal duration and dose of perioperative statin therapy should be defined.

Statins and Peripheral Arterial Disease: Potential Mechanisms and Clinical Benefits

Peripheral arterial disease (PAD) is a manifestation of widespread atherosclerosis. Lipid modification (especially with statins) is a component of the treatment of patients with PAD since this condition is considered a coronary heart disease equivalent. This review considers the mechanism of action of statins in PAD. Statins have been shown to reduce the incidence of new coronary events in patients with PAD. However, surveys suggest that many such patients remain undertreated. Statins can also increase walking distance in patients with PAD. There is also evidence that statins can improve renal function in these patients. Several other actions of statins are considered in this review. PAD patients have an increased morbidity and mortality, largely due to myocardial infarction and stroke. Recognizing and treating these high-risk patients as early as possible should be a priority.

An overview of statin-associated proteinuria

Statins are an established therapeutic modality for the treatment of hypercholesterolemia. Although they generally exhibit a good efficacy and tolerability profile, their reputation has been tarnished as a result of reports of myotoxicity and, more recently, observations of proteinuria. The increased incidence of proteinuria with rosuvastatin was of particular concern, and raised questions about the renoprotective actions of statins. Different hypotheses have been put forward to explain the mechanisms of statin-induced proteinuria. The multifarious effects of statins, independent of their effects on cholesterol-lowering, form the basis of such hypotheses. However, rosuvastatin-associated proteinuria is transient and reversible and even at the highest dose did not affect renal function after prolonged treatment. It would appear that clinically relevant proteinuria is not associated solely with rosuvastatin and might represent a minor class effect of statins with a fairly low incidence. However, definitive proof of this assertion will need to be provided by rigorous testing.

Lipid peroxidation and renal cell carcinoma: further supportive evidence and new mechanistic insights

We have recently proposed lipid peroxidation as a unifying mechanistic pathway by which several seemingly unrelated risk/protective factors (obesity, hypertension, diabetes, smoking, oophorectomy/hysterectomy, parity, antioxidants) affect renal cell carcinoma development. In experimental studies, increased lipid peroxidation is a principal mechanistic pathway in renal carcinogenesis induced by different chemicals. In this communication, we provide additional lines of evidence that further support a role for lipid peroxidation on renal cell cancer development. (1) Lipid peroxidation may explain the role of other risk (analgesic use, pre-eclampsia) or protective (alcohol intake, oral contraceptives) factors for renal cell carcinoma. (2) Additional experimental evidence supports lipid peroxidation as an important mechanism in renal carcinogenesis, and (3) Existing evidence support a cross-talk between the lipid peroxidation pathway and other pathways that are relevant to renal carcinogenesis, such as apoptosis, VHL, and possibly other pathways.

Adjuvant strategies for prevention of glomerulosclerosis

The glomerulosclerosis which frequently complicates diabetes and severe hypertension is mediated primarily by increased mesangial production and activation of transforming growth factor-beta (TGF-beta), which acts on mesangial cells to boost their production of matrix proteins while suppressing extracellular proteolytic activity. Hyperglycemia and glomerular hypertension work in various complementary ways to stimulate superoxide production via NADPH oxidase in mesangial cells; the resulting oxidant stress results in the induction and activation of TFG-beta. Nitric oxide, generated by glomerular capillaries and by mesangial cells themselves, functions physiologically to oppose mesangial TGF-beta overproduction; however, NO bioactivity is compromised by oxidant stress. In addition to low-protein diets and drugs that suppress angiotensin II activity, a variety of other agents and measures may have potential for impeding the process of glomerulosclerosis. These include vitamin E, which blunts the rise in mesangial diacylglycerol levels induced by hyperglycemia; statins and (possibly) policosanol, which down-regulate NADPH oxidase activity by diminishing isoprenylation of Rac1; lipoic acid, whose potent antioxidant activity antagonizes the impact of oxidant stress on TGF-beta expression; pyridoxamine, which inhibits production of advanced glycation endproducts; arginine, high-dose folate, vitamin C, and salt restriction, which may support glomerular production of nitric oxide; and estrogen and soy isoflavones, which may induce nitric oxide synthase in glomerular capillaries while also interfering with TGF-beta signaling. Further research along these lines may enable the development of complex nutraceuticals which have important clinical utility for controlling and preventing glomerulosclerosis and renal failure. Most of these measures may likewise reduce risk for left ventricular hypertrophy in hypertensives, inasmuch as the signaling mechanisms which mediate this disorder appear similar to those involved in glomerulosclerosis.

Medical treatment of renal artery stenosis: is it effective and appropriate?

Recent advances in endovascular technology have radically changed the options available for the clinical management of the patient with renovascular disease. These treatment options have fueled an ongoing debate concerning the appropriateness of interventional endovascular therapy for the stenotic renal artery versus conservative medical management. This review examines a typical clinical case scenario and analyzes relevant published literature and the recent guidelines from the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) highlighting the significant shortcomings of evidence-based data when it comes to the management of this complex patient population. Early diagnosis provides the best opportunity for appropriate utilization of therapeutic options and rational timing of deployment of interventional techniques. Recommendations for conservative medical management are made based on the review of the medical management arms of the published interventional series. In addition, suggestions are made for practical modifications to the JNC 7 hypertension management protocol to better address the challenging diagnostic and management issues raised by the renovascular patient.

[Protective effects of Chailing Guiqi Decoction combined with lumbrukinase on renal function in rats with adriamycin nephropathy]

OBJECTIVE

To study the protective efffects of Chailing Guiqi Decoction (CLGQD) combined with lumbrukinase on renal function in rats with adriamycin nephropathy.

METHODS

Thirty-six SD rats were randomly divided into four groups: normal control group, untreated group, simvastatin-treated group and CLGQD -treated group. Adriamycin nephropathy was induced by intravenous injection with 5 mg/kg adriamycin. After seven-day treatment, quantitative measurement of 24-h urine protein was determined with trichloroacetic acid, and serum total protein (TP), albumin (Alb), total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), creatinine (Cr) and blood urea nitrogen (BUN) were assessed using automatic biochemistry analyzer. The pathomorphological changes of renal tissues were observed with light and electron microscopes.

RESULTS

In the untreated group, the 24-h urine protein excretion, serum TC, TG, LDL, Cr and BUN were significantly higher than those in the normal control group (P<0.05 or P<0.01), while the serum TP, Alb, HDL were significantly lower than those in the normal control group (P<0.01). In the CLGQD-treated group, the 24-h urine protein excretion, serum TC, TG, LDL, Cr and BUN were significantly lower as compared with those in the untreated group (P<0.05 or P<0.01), while the serum TP, Alb and HDL were significantly higher as compared with those in the untreated group (P<0.05 or P<0.01). The pathomorphological findings of the renal tissues under the light microscope in the untreated group showed focal segmental glomerulosclerosis in a few of glomerulus, degenerated and swelled proximal tubular epithelial cells, proteins in cast formation in some renal tubules and scattered fibrosis in interstitial tissues of the kidney, while the electron microscope images showed the fusion of foot processes in glomerular epithelial cells. The pathomorphological changes in the CLGQD-treated group were slighter than those in the untreated group.

CONCLUSION

CLGQD combined with lumbrukinase can reduce proteinuria, regulate lipid metabolism, protect renal function, and delay progressive renal damage in rats.

The Relationship Between Albuminuria and Hormone Therapy in Postmenopausal Women

BACKGROUND

Elevated urinary albumin excretion and hormone therapy (HT) are associated with increased risk for cardiovascular events. We assessed the relationship between albuminuria and the use of hormonal preparations in postmenopausal women.

METHODS

Data from the Insulin Resistance Atherosclerosis Study were obtained at baseline and 5-year follow-up for analysis. The generalized estimating equation procedure accounting for repeated measures was used for this analysis. HT was the main predictor variable, and log(e) urine albumin-creatinine ratio (ACR) was the main outcome variable.

RESULTS

Four hundred ninety-one menopausal women were included in the analysis, 36% (n = 179) of whom received HT (either oral estrogen, progesterone, or combination therapy). At baseline, abnormal albuminuria (ACR > or = 25 mg/g) was present in 11% of women on HT and 17% not on HT (P = 0.02). After adjusting for demographics, the presence of diabetes and hypertension, and kidney function, HT was associated with a 19% reduction in ACR (P = 0.008) and an odds ratio of 0.67 (95% confidence interval, 0.43 to 1.01; P = 0.06) for the presence of abnormal albuminuria. Other predictors of abnormal albuminuria included diabetes, blood pressure, and triglyceride level.

CONCLUSION

Results of this study suggest that HT is associated with a reduction in urinary albumin excretion in postmenopausal women.

Matrix metalloproteinases and diabetic vascular complications

Diabetes mellitus (DM) is associated with an increased incidence of cardiovascular events and microvascular complications. These complications contribute to the morbidity and mortality associated with DM. There is increasing evidence supporting a role for matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of matrix metalloproteinases - TIMPs) in the atherosclerotic process. However, the relationship between MMPs/TIMPs and diabetic angiopathy is less well defined. Hyperglycemia directly or indirectly (eg, via oxidative stress or advanced glycation products) increases MMP expression and activity. These changes are associated with histologic alterations in large vessels. On the other hand, low proteolytic activity of MMPs contributes to diabetic nephropathy. Within atherosclerotic plaques an imbalance between MMPs and TIMPs may induce matrix degradation, resulting in an increased risk of plaque rupture. Furthermore, because MMPs enhance blood coagulability, MMPs and TIMPs may play a role in acute thrombotic occlusion of vessels and consequent cardiovascular events. Some drugs can inhibit MMP activity. However, the precise mechanisms involved are still not defined. Further research is required to demonstrate the causative relationship between MMPs/TIMPs and diabetic atherosclerosis. It also remains to be established if the long-term administration of MMP inhibitors can prevent acute cardiovascular events.

The value of risk-factor ("black-box") epidemiology

Risk-factor epidemiology has been denigrated by some as an empty search for associations, unguided by underlying theory. It has been defended for occasionally identifying useful (if poorly understood) potential interventions. We further defend risk-factor epidemiology as a valuable source of seemingly unrelated facts that await coherent explanation by novel theories and that provide empiric tests of theories. We illustrate these points with a theory that invokes lipid peroxidation as an explanation of an apparently incoherent accumulation of facts about renal-cell carcinoma. The example illustrates the value of viewing epidemiologic, laboratory, and clinical observations as a body of facts demanding explanation by proposed causal theories, whether or not those observations were collected with any hypothesis in mind.

Treatment of lipids and type 2 diabetes

The development of type 2 diabetes is increasing in epidemic proportions. There is a significant risk for cardiovascular disease, which is the most prevalent and detrimental complication for the diabetic population. Serum lipid abnormalities are common in patients with diabetes, and due to this increased vascular risk, it is recommended to aggressively treat the hyperlipidemia. Therefore, intensive lipid-lowering therapy should be used for primary and secondary prevention against macrovascular complications for patients with type 2 diabetes. In this article some of the key studies justifying the need for lipid reduction in patients with type 2 diabetes are reviewed and practical guidelines for management of the dyslipidemia are suggested.