Statins for improving renal outcomes: a meta-analysis

High-density lipoprotein: structural and functional changes under uremic conditions and the therapeutic consequences

High-density lipoprotein (HDL) has attracted interest as a therapeutic target in cardiovascular diseases in recent years. Although many functional mechanisms of the vascular protective effects of HDL have been identified, increasing the HDL plasma level has not been successful in all patient cohorts with increased cardiovascular risk. The composition of the HDL particle is very complex and includes diverse lipids and proteins that can be modified in disease conditions. In patients with chronic kidney disease (CKD), the accumulation of uremic toxins, high oxidative stress, and chronic micro-inflammatory conditions contribute to changes in the HDL composition and may also account for protein/lipid modifications. These conditions are associated with a decreased protective function of HDL. Therefore, the HDL quantity and the functional quality of the particle must be considered. This review summarizes the current knowledge of dyslipidemia in CKD patients, the effects of lipid-modulating therapy, and the structural modifications of HDL that are associated with dysfunction.

Renoprotective effects of atorvastatin compared with pravastatin on progression of early diabetic nephropathy

Introduction

Several studies have shown that statins suppress the progression of diabetic nephropathy. However, few reports have directly compared the renoprotective effects between potent and conventional statins.

Materials and Methods

Patients with diabetic nephropathy, selected as those with a serum creatinine level of 0.9–1.5 mg/dL and simultaneously having either microalbuminuria or positive proteinuria, were randomly assigned to one of three groups: a conventional diet therapy group, a group given 10 mg of pravastatin and a group given 10 mg of atorvastatin. Renal function was evaluated before and after a 12-month period of therapy.

Results

The atorvastatin group had a significant decrease in low-density lipoprotein cholesterol at 3 months and thereafter compared with the other groups. The urinary albumin-to-creatinine ratio significantly decreased in the atorvastatin group; the degree of this decrease was significantly greater than that in the diet therapy group. The kidney function estimated with cystatin C (CysC) and the estimated glomerular filtration rate calculated from CysC were significantly preserved in the atorvastatin group compared with the pravastatin group. In a multivariate regression analysis, the use of atorvastatin was the only explanatory variable for the changes in CysC; this was independent of changes in low-density lipoprotein cholesterol.

Conclusions

Atorvastatin is more effective than pravastatin for the prevention of increase in CysC, and this renoprotective effect was considered to a result of the pleiotropic effect of atorvastatin independent of its lipid-lowering effect. This study was registered with UMIN (no. UMIN 000001774).

Preserving residual renal function in dialysis: what we know

Residual renal function confers a survival benefit among dialysis patients thought to be related to greater volume removal and solute clearance. Whether the presence of residual renal function is protective or merely a marker for better health is not clear. The basic mechanisms governing the decline or persistence of residual renal function are poorly understood and few studies have examined the role of medical therapy in its preservation. Dialysis modality, inflammatory processes often associated with comorbid diseases (including diabetes mellitus and obesity), volume dysregulation, and vitamin D deficiency are predictive of residual renal function decline. We review potential mechanisms for preservation of remaining glomerular filtration rate among chronic dialysis patients.

Is Mitral Annular Calcification Associated With Atherosclerotic Risk Factors and Severity and Complexity of Coronary Artery Disease?

We assessed the association of mitral annular calcification (MAC) with atherosclerotic risk factors and severity and complexity of coronary artery disease (CAD). Cardiac catheterization reports and electronic medical records from 2010 to 2011 were retrospectively reviewed. A total of 481 patients were divided into 2 groups: MAC present (209) and MAC absent (272). All major cardiovascular risk factors, comorbidities, and coronary lesion characteristics were included. On linear regression analysis, age ( P = .001, β 1.12) and female gender ( P = .031, β 0.50) were the independent predictors of MAC. Mitral annular calcification was not independently associated with the presence of lesions with >70% stenosis ( P = .283), number of obstructive vessels ( P = .469), lesions with 50% to 70% stenosis ( P = .458), and Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery score ( P = .479). Mitral annular calcification is probably a benign marker of age-related degenerative changes in the heart independent of the severity and complexity of CAD.

The effects of GLP-1 analogues, DPP-4 inhibitors and SGLT2 inhibitors on the renal system

Diabetic nephropathy (DN) affects an estimated 20%-40% of patients with type 2 diabetes mellitus (T2DM). Key modifiable risk factors for DN are albuminuria, anaemia, dyslipidaemia, hyperglycaemia and hypertension, together with lifestyle factors, such as smoking and obesity. Early detection and treatment of these risk factors can prevent DN or slow its progression, and may even induce remission in some patients. DN is generally preceded by albuminuria, which frequently remains elevated despite treatment in patients with T2DM. Optimal treatment and prevention of DN may require an early, intensive, multifactorial approach, tailored to simultaneously target all modifiable risk factors. Regular monitoring of renal function, including urinary albumin excretion, creatinine clearance and glomerular filtration rate, is critical for following any disease progression and making treatment adjustments. Dipeptidyl peptidase (DPP)-4 inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels without additional risk of hypoglycaemia, and may also reduce albuminuria. Further investigation of the potential renal benefits of DPP-4 and SGLT2 inhibitors is underway.

Meta-analysis of the effect of statins on renal function

Statins can significantly improve the lipid profile and reduce cardiovascular events. However, beneficial effects of statins on renal function are still controversial. PubMed, the Cochrane Central Register of Controlled Trials, Web of Knowledge, and ClinicalTrials.gov Web sites were searched for randomized controlled trials. The selected studies reported renal function during treatment with statins and control. Forty-one studies with a total of 88,523 participants were included in this analysis. Compared with statins, placebo group had significantly decreased estimated glomerular filtration rate (eGFR): the standardized mean difference (SMD) of eGFR in change from baseline was 0.15 (95% confidence interval [CI] 0.07 to 0.23, p = 0.0004) in patients with eGFR >60 ml/min and 0.09 (95% CI 0.01 to 0.17, p = 0.02) in patients with eGFR 30 to 60 ml/min. Compared with placebo, statin group had significantly greater reduction of proteinuria: the SMD of proteinuria in change from baseline was -1.12 (95% CI -1.95 to -0.30, p = 0.008) in patients with urinary protein excretion 30 to 300 mg/day and -0.77 (95% CI -1.35 to -0.18, p = 0.01) in patients with urinary protein excretion > 300 mg/day. eGFR was significantly greater with high-intensity statins than with moderate-intensity statins (SMD 0.12, 95% CI 0.08 to 0.16, p = 0.00001). Placebo group had significantly decreased eGFR for 1 to 3 years (SMD 0.05, 95% CI 0.02 to 0.08, p = 0.003) and >3 years (SMD 0.14, 95% CI 0.04 to 0.25, p = 0.007) of statin therapy. The beneficial effect of statins on renal function may be dosage related and duration dependent. In conclusion, statins appear to decrease the rate of reduction of eGFR and slow the progression of pathologic proteinuria moderately.

High-performance information search filters for CKD content in PubMed, Ovid MEDLINE, and EMBASE

BACKGROUND

Finding relevant articles in large bibliographic databases such as PubMed, Ovid MEDLINE, and EMBASE to inform care and future research is challenging. Articles relevant to chronic kidney disease (CKD) are particularly difficult to find because they are often published under different terminology and are found across a wide range of journal types.

STUDY DESIGN

We used computer automation within a diagnostic test assessment framework to develop and validate information search filters to identify CKD articles in large bibliographic databases.

SETTING & PARTICIPANTS

22,992 full-text articles in PubMed, Ovid MEDLINE, or EMBASE.

INDEX TEST

1,374,148 unique search filters.

REFERENCE TEST

We established the reference standard of article relevance to CKD by manual review of all full-text articles using prespecified criteria to determine whether each article contained CKD content or not. We then assessed filter performance by calculating sensitivity, specificity, and positive predictive value for the retrieval of CKD articles. Filters with high sensitivity and specificity for the identification of CKD articles in the development phase (two-thirds of the sample) were then retested in the validation phase (remaining one-third of the sample).

RESULTS

We developed and validated high-performance CKD search filters for each bibliographic database. Filters optimized for sensitivity reached at least 99% sensitivity, and filters optimized for specificity reached at least 97% specificity. The filters were complex; for example, one PubMed filter included more than 89 terms used in combination, including "chronic kidney disease," "renal insufficiency," and "renal fibrosis." In proof-of-concept searches, physicians found more articles relevant to the topic of CKD with the use of these filters.

LIMITATIONS

As knowledge of the pathogenesis of CKD grows and definitions change, these filters will need to be updated to incorporate new terminology used to index relevant articles.

CONCLUSIONS

PubMed, Ovid MEDLINE, and EMBASE can be filtered reliably for articles relevant to CKD. These high-performance information filters are now available online and can be used to better identify CKD content in large bibliographic databases.

Statins in chronic kidney disease and kidney transplantation

HMG-CoA reductase inhibitors (statins) have been shown to improve cardiovascular (CV) outcomes in the general population as well as in patients with cardiovascular disease (CVD). Statins' beneficial effects have been attributed to both cholesterol-lowering and cholesterol-independent "pleiotropic" properties. By their pleiotropic effects statins have been shown to reduce inflammation, alleviate oxidative stress, modify the immunologic responses, improve endothelial function and suppress platelet aggregation. Patients with chronic kidney disease (CKD) exhibit an enormous increase in CVD rates even from early CKD stages. As considerable differences exist in dyslipidemia characteristics and the pathogenesis of CVD in CKD, statins' CV benefits in CKD patients (including those with a kidney graft) should not be considered unequivocal. Indeed, accumulating clinical evidence suggests that statins exert diverse effects on dialysis and non-dialysis CKD patients. Therefore, it seems that statins improve CV outcomes in non-dialysis patients whereas exert little (if any) benefit in the dialysis population. It has also been proposed that dyslipidemia might play a causative role or even accelerate renal injury. Moreover, ample experimental evidence suggests that statins ameliorate renal damage. However, a high quality randomized controlled trial (RCT) and metaanalyses do not support a beneficial role of statins in renal outcomes in terms of proteinuria reduction or retardation of glomerular filtration rate (GFR) decline.

Clinical therapeutic strategies for early stage of diabetic kidney disease

Diabetic kidney disease (DKD) is the most common cause of chronic kidney disease, leading to end-stage renal disease and cardiovascular disease. The overall number of patients with DKD will continue to increase in parallel with the increasing global pandemic of type 2 diabetes. Based on landmark clinical trials, DKD has become preventable by controlling conventional factors, including hyperglycemia and hypertension, with multifactorial therapy; however, the remaining risk of DKD progression is still high. In this review, we show the importance of targeting remission/regression of microalbuminuria in type 2 diabetic patients, which may protect against the progression of DKD and cardiovascular events. To achieve remission/regression of microalbuminuria, several steps are important, including the early detection of microalbuminuria with continuous screening, targeting HbA1c < 7.0% for glucose control, the use of renin angiotensin system inhibitors to control blood pressure, the use of statins or fibrates to control dyslipidemia, and multifactorial treatment. Reducing microalbuminuria is therefore an important therapeutic goal, and the absence of microalbuminuria could be a pivotal biomarker of therapeutic success in diabetic patients. Other therapies, including vitamin D receptor activation, uric acid-lowering drugs, and incretin-related drugs, may also be promising for the prevention of DKD progression.

Effects of lowering LDL cholesterol on progression of kidney disease

Lowering LDL cholesterol reduces the risk of developing atherosclerotic events in CKD, but the effects of such treatment on progression of kidney disease remain uncertain. Here, 6245 participants with CKD (not on dialysis) were randomly assigned to simvastatin (20 mg) plus ezetimibe (10 mg) daily or matching placebo. The main prespecified renal outcome was ESRD (defined as the initiation of maintenance dialysis or kidney transplantation). During 4.8 years of follow-up, allocation to simvastatin plus ezetimibe resulted in an average LDL cholesterol difference (SEM) of 0.96 (0.02) mmol/L compared with placebo. There was a nonsignificant 3% reduction in the incidence of ESRD (1057 [33.9%] cases with simvastatin plus ezetimibe versus 1084 [34.6%] cases with placebo; rate ratio, 0.97; 95% confidence interval [95% CI], 0.89 to 1.05; P=0.41). Similarly, allocation to simvastatin plus ezetimibe had no significant effect on the prespecified tertiary outcomes of ESRD or death (1477 [47.4%] events with treatment versus 1513 [48.3%] events with placebo; rate ratio, 0.97; 95% CI, 0.90 to 1.04; P=0.34) or ESRD or doubling of baseline creatinine (1189 [38.2%] events with treatment versus 1257 [40.2%] events with placebo; rate ratio, 0.93; 95% CI, 0.86 to 1.01; P=0.09). Exploratory analyses also showed no significant effect on the rate of change in eGFR. Lowering LDL cholesterol by 1 mmol/L did not slow kidney disease progression within 5 years in a wide range of patients with CKD.

Effects of single pill-based combination therapy of amlodipine and atorvastatin on within-visit blood pressure variability and parameters of renal and vascular function in hypertensive patients with chronic kidney disease

Both strict blood pressure (BP) control and improvements in BP profile such as BP variability are important for suppression of renal deterioration and cardiovascular complication in hypertension and chronic kidney disease (CKD). In the present study, we examined the beneficial effects of the single pill-based combination therapy of amlodipine and atorvastatin on achievement of the target BP and clinic BP profile, as well as markers of vascular and renal damages in twenty hypertensive CKD patients. The combination therapy with amlodipine and atorvastatin for 16 weeks significantly decreased clinic BP, and achievement of target BP control was attained in an average of 45% after the combination therapy in spite of the presence of no achievement at baseline. In addition, the combination therapy significantly decreased the within-visit BP variability. With respect to the effects on renal damage markers, combination therapy with amlodipine and atorvastatin for 16 weeks significantly decreased albuminuria (urine albumin-to-creatinine ratio, 1034 ± 1480 versus 733 ± 1218 mg/g-Cr, P < 0.05) without decline in estimated glomerular filtration rate. Concerning parameters of vascular function, the combination therapy significantly improved both brachial-ankle pulse wave velocity (baPWV) and central systolic BP (cSBP) (baPWV, 1903 ± 353 versus 1786 ± 382 cm/s, P < 0.05; cSBP, 148 ± 19 versus 129 ± 23 mmHg, P < 0.01). Collectively, these results suggest that the combination therapy with amlodipine and atorvastatin may exert additional beneficial effects on renal and vascular damages as well as BP profile in addition to BP lowering in hypertension with CKD.

The pleiotropic effects of the hydroxy-methyl-glutaryl-CoA reductase inhibitors in renal disease

It is well known that statins exert their main effect by inhibiting cholesterol synthesis through the inhibition of the 3-hydroxy-3-methyl-glutaryl-CoA reductase enzyme. The pleiotropic effects of statins, which are independent of their inhibition of cholesterol synthesis, have explained many of the beneficial effects of these drugs in a variety of disorders such as malignancies, infection, and sepsis, as well as in cardiovascular and rheumatologic disorders. However, the role of these drugs in renal disorders remains controversial. In the present review, we examine the most recent findings involving statins and renal disease among different clinical scenarios, including chronic kidney disease, contrast-induced nephropathy, renal injury after coronary artery bypass surgery, and renal transplant patients.

Unintended effects of statins from observational studies in the general population: systematic review and meta-analysis

BACKGROUND

Efficacy of statins has been extensively studied, with much less information reported on their unintended effects. Evidence from randomized controlled trials (RCTs) on unintended effects is often insufficient to support hypotheses generated from observational studies. We aimed to systematically assess unintended effects of statins from observational studies in general populations with comparison of the findings where possible with those derived from randomized trials.

METHODS

Medline (1998 to January 2012, week 3) and Embase (1998 to 2012, week 6) were searched using the standard BMJ Cohort studies filter. The search was supplemented with reference lists of all identified studies and contact with experts in the field. We included prospective studies with a sample size larger than 1,000 participants, case control (of any size) and routine health service linkage studies of over at least one year duration. Studies in subgroups of patients or follow-up of patient case series were excluded, as well as hospital-based cohort studies.

RESULTS

Ninety studies were identified, reporting on 48 different unintended effects. Statins were associated with lower risks of dementia and cognitive impairment, venous thrombo-embolism, fractures and pneumonia, but these findings were attenuated in analyses restricted to higher quality studies (respectively: OR 0.74 (95% CI 0.62 to 0.87); OR 0.92 (95% CI 0.81 to 1.03); OR 0.97 (95% CI 0.88 to 1.05); OR 0.92 (95% CI 0.83 to 1.02)); and marked heterogeneity of effects across studies remained. Statin use was not related to any increased risk of depression, common eye diseases, renal disorders or arthritis. There was evidence of an increased risk of myopathy, raised liver enzymes and diabetes (respectively: OR 2.63 (95% CI 1.50 to 4.61); OR 1.54 (95% CI 1.47 to 1.62); OR 1.31 (95% CI 0.99 to 1.73)).

CONCLUSIONS

Our systematic review and meta-analyses indicate that high quality observational data can provide relevant evidence on unintended effects of statins to add to the evidence from RCTs. The absolute excess risk of the observed harmful unintended effects of statins is very small compared to the beneficial effects of statins on major cardiovascular events.

Association of the triglycerides to high-density lipoprotein cholesterol ratio with the risk of chronic kidney disease: analysis in a large Japanese population

OBJECTIVES

To investigate the relationship between triglycerides to high-density lipoprotein cholesterol ratio (TG/HDL-C) and chronic kidney disease (CKD).

METHODS

We used data from 216,007 Japanese adults who participated in a nationwide health checkup program. Men (n = 88,516) and women (n = 127,491) were grouped into quartiles based on their TG/HDL-C levels (<1.26, 1.26-1.98, 1.99-3.18, and >3.18 in men; <0.96, 0.96-1.44, 1.45-2.22, and >2.22 in women). We cross-sectionally assessed the association of TG/HDL-C levels with CKD [defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m(2) (low eGFR) and/or proteinuria (defined as urinary protein ≥ 1+ on dipstick testing)], low eGFR, and proteinuria.

RESULTS

The prevalence of CKD, low eGFR, and proteinuria increased significantly with elevating quartiles of TG/HDL-C in both genders (all P for trend <0.001). Participants in the highest quartile of TG/HDL-C had a significantly greater risk of CKD than those in the lowest quartile after adjustment for the relevant confounding factors (odds ratio: 1.57, 95% confidence interval: 1.49-1.65 in men; 1.41, 1.34-1.48 in women, respectively). Furthermore, there were significant associations with low eGFR and proteinuria. In stratified analysis, the risk of CKD increased linearly with greater TG/HDL-C levels in participants with and without hypertension, diabetes, and obesity. Moreover, higher TG/HDL-C levels were relevant for CKD, especially in participants with hypertension and diabetes (P for interaction <0.001, respectively).

CONCLUSIONS

An elevated TG/HDL-C is associated with the risk of CKD in the Japanese population.

Effect of single tablet of fixed-dose amlodipine and atorvastatin on blood pressure/lipid control, oxidative stress, and medication adherence in type 2 diabetic patients

BACKGROUND

Oxidized low-density lipoprotein (LDL) plays central roles in the formation and progression of atherosclerotic lesions. Malondialdehyde (MDA)-modified LDL (MDA-LDL) is speculated to be generated as a result of oxidative stress in the human body. Because both amlodipine and atorvastatin have been reported to reduce oxidative stress, it is expected that both drugs would have a favorable influence to reduce oxidative stress.

OBJECTIVE

The objective of this study was to investigate the effects of a single pill of amlodipine (5 mg)/atorvastatin (10 mg) on oxidative stress, blood pressure/lipid control and adherence to medication in patients with type 2 diabetes.

METHODS

This combination tablet was administered to 29 patients (16 male), and MDA-LDL, blood pressure, lipid profile, renal/liver function, CPK, hs-CRP, adiponectin, BNP, and HbA1c were measured at baseline, 6, and 12 months, and baPWV and mean IMT were measured at baseline and 12 months. Medication adherence was examined using a questionnaire at 6 months.

RESULTS

MDA-LDL was decreased significantly. LDL-C, TG, and Cr were significantly decreased at 6 and 12 months compared with baseline. eGFR was increased at 6 months, and urinary albumin/creatinine ratio was decreased at 12 months. BNP was decreased at 6 and 12 months, and adiponectin was increased at 12 months. Both mean IMT and baPWV were significantly decreased. The results of the questionnaire showed that 93% of patients were satisfied with this medication. No severe adverse event was observed.

CONCLUSION

This combination tablet controlled both hypertension and dyslipidemia well in type 2 diabetic patients. The deceases in mean IMT and baPWV might suggest the improvement of atherosclerosis by this medication, which could be caused by the reduction of oxidative stress measured by MDA-LDL. In addition, this medication is expected to improve medication adherence.

Antiplatelet and Lipid-lowering Drugs in Hypertension

Antiplatelet therapy, and low-dose acetylsalicylic acid (ASA) in particular, is recommended in hypertensive patients with previous cardiovascular events and is considered in hypertensive patients with reduced renal function or a high cardiovascular (CV) risk, provided blood pressure is well-controlled. Acetylsalicylic acid is not recommended in low-to-moderate risk hypertensive patients in whom absolute benefit and harm are equivalent. Further trials evaluating antithrombotic therapy including newer agents in hypertension are needed. Women at high and moderate risk of pre-eclampsia are advised to take a low dose of ASA daily from 12 weeks of gestation until delivery. In addition to their lipid-lowering effects, statins induce a small blood pressure reduction. The 2013 European Society of Hypertension (ESH)/European Society of Cardiology (ESC) guidelines recommend using statin therapy in hypertensive patients at moderate-to-high CV risk to achieve the target low-density lipoprotein (LDL) cholesterol value <3 mmol/l (115 mg/dl). For individuals with manifest CV disease or at very high CV risk, a more aggressive LDL target of <1.8 mmol/l (70 mg/dl) is recommended.

Statins stabilize the renal function of IgA nephropathy

BACKGROUND

The renoprotective pleiotropic effect of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has recently been reported by several investigators. However, the effect of statins on IgA nephropathy (IgAN) is still unknown.

METHODS

We selected 24 IgAN patients who had newly started statin therapy and were not treated with steroids and immunosuppressive agents during the observation period. We analyzed and compared clinical findings 1 year before and after treatment.

RESULTS

Mean age was 50.5 ± 9.91 years and mean blood pressure was 90.9 ± 10.8 mmHg. Renal function was slightly deteriorated, serum creatinine was 1.03 (0.71-1.24) mg/dL and estimated glomerular filtration rate (eGFR) was 55.8 ± 22.8 mL/min. Lipid metabolism was poorly controlled [total cholesterol 247.7 ± 35.7 mg/dL, low-density lipoprotein cholesterol 151.5 (140.8-172.8) mg/dL, and triglyceride 163.0 (126.3-243.8) mg/dL]. Mild urinary abnormality was observed [proteinuria: 0.50 (0.22-1.29) g/g creatinine, urinary red blood cells 1.0 (0.2-5.0) per high power field]. After 1 year of statin treatment, lipid control was significantly better than at baseline. Proteinuria was not significantly decreased but renal function was improved. eGFR changed from a -5.9% decrease to a 2.4% increase (p = 0.0098).

CONCLUSION

Our results indicated that statins stabilized the renal function of IgAN patients independent of their reduction of proteinuria.

Comparative efficacy and adverse effects of the addition of ezetimibe to statin versus statin titration in chronic kidney disease patients

BACKGROUND AND OBJECTIVES

The recent SHARP trial clearly demonstrated that a reduction in low-density lipoprotein (LDL) cholesterol with a daily regimen of simvastatin plus ezetimibe safely reduced the incidence of major atherosclerotic events in patients with chronic kidney disease (CKD). We aimed to compare the efficacy of and adverse effects from statin uptitration versus statin in combination with ezetimibe since only a few studies have addressed this question.

METHODS

This was a randomized, open-label, multicenter trial that included 286 patients with CKD whose LDL cholesterol levels were not reduced below 120 mg/dl despite a minimum dose of statin therapy. Patients received double doses of statin or usual statin dose with the addition of ezetimibe 10 mg daily. The observation period was 1 year during which time patients were checked regularly in clinic for adverse effects as well as for usual laboratory examinations. The key prespecified outcome was the incidence of adverse effects, which included skeletal muscle complaints, myalgia, muscle weakness, and muscle cramps with and without elevated CK levels. Increases in alanine transaminase (ALT) or aspartate transaminase (AST) levels >2 times the upper limit of normal (ULN) were considered clinically significant adverse effects.

RESULTS

Adverse events occurred in 9/145 in the combination group and in 24/141 in the statin uptitration group (p < 0.01). Moreover, in patients with CKD of stages 3-5, rates were 6/58 in the combination group versus 20/52 in the statin uptitration group (p < 0.01). No serious adverse effects such as rhabdomyolysis were noted in either group. Serum creatinine levels remained essentially unchanged in both groups except in CKD stages 4 and 5. Reductions in LDL cholesterol were similar between the two groups at the start of and at the end of the study. During the study, no atherosclerotic events were reported in either group.

CONCLUSION

When statin uptitration produces adverse effects such as myopathy, combination therapy with ezetimibe is recommended instead of statin alone.

The lipid story in chronic kidney disease: a long story with a happy end?

Cardiovascular (CV) morbidity and mortality increase with the severity of kidney disease, reaching 30 times higher mortality rates in dialysis patients compared with the general population. Although dyslipidemia is a well-established CV risk factor in the general population, the relationship between lipid disorders and CV risk in patients with chronic kidney disease (CKD) is less clear. Despite the clear evidence that statins reduce the risk of atherosclerotic events and death from cardiac causes in individuals without CKD, the use of statins in patients with kidney disease is significantly less frequent. For a long time, one of the explanations was the lack of a prospective, randomized, controlled study designed specifically to CKD patients. After recent publication of the data from Study of Heart and Renal Protection trial, given the safety and potential efficacy of statins, this lipid-lowering treatment should be administered more frequently to individuals with CKD stage 1-4, as well as those undergoing dialysis.

Renal angioplasty for atherosclerotic renal artery stenosis: Cardiologist's perspective

Atherosclerotic renal artery stenosis (ARAS) is frequently associated with concomitant coronary and peripheral arterial disease with a significant impact on cardiovascular morbidity and mortality. Renal angioplasty of ARAS is more challenging because of increased incidence of technical failures, complications, and restenosis; while there is barely perceptible control of hypertension and only marginal improvement in renal function. This is because most of the patient population in recent randomized trials had unmanifested or clinically silent renovascular disease. Manifestations of RAS should be looked for and incorporated in the management plan particularly before deciding for revascularization. In the absence of clinical manifestation like renovascular hypertension, ischemic nephropathy, left ventricular failure, or unstable coronary syndromes; mere presence of RAS is analogous to presence of concomitant peripheral arterial disease which increases risk of adverse coronary events. Dormant-RAS in the absence of any manifestations can be managed with masterly inactivity. Chronological sequence of events and clinical condition of the patient help in decision making by identifying progressive renovascular disease. Selecting patients for renal artery stenting who actually will benefit from revascularization shall also decrease the unnecessary complications inherent with any interventional procedure. The present review is an attempt to analyze the current view on the diagnostic and management issues more specifically about the need and rationale behind angioplasty.

Is obesity a risk factor for chronic kidney disease in children?

There is a rapid increase worldwide in the prevalence of obesity in adults and children. Obesity is not only a comorbidity for chronic kidney disease (CKD) but may also be a risk factor for CKD. Epidemiological correlations and pathophysiological changes have been observed associating obesity with CKD. Low birth weight may be associated with both obesity and low nephron mass, leading to CKD later in life. Elevated levels of adipokines, such as leptin and adiponectin, in obesity may be factors in CKD pathogenesis and progression. Furthermore, various other factors, such as hypertension, increased cardiovascular morbidity, insulin resistance, dyslipidemia, and lipotoxicity, may play significant roles in the pathogenesis of CKD in obesity. Reduction in obesity, which is a potentially modifiable risk factor, might help decrease the burden of CKD in the population. Apart from individualized options, community-based interventions have the potential to create a strong impact in this condition.

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.

Dyslipoproteinemia and impairment of renal function in diabetic kidney disease: an analysis of animal studies, observational studies, and clinical trials

Dyslipoproteinemia is highly prevalent in diabetes, chronic kidney disease, and diabetic kidney disease (DKD). Both diabetes and chronic kidney disease (CKD) are associated with hypertriglyceridemia, lower high-density lipoprotein, and higher small, dense low-density lipoprotein. A number of observational studies have reported that dyslipidemia may be associated with albuminuria, renal function impairment, and end-stage renal disease (ESRD) in the general population, and especially in CKD and DKD patients. Diabetic glomerulopathy and the related albuminuria are the main manifestations of DKD. Numerous animal studies support the finding that glomerular atherosclerosis is the main mechanism of glomerulosclerosis in CKD and DKD. Some randomized, controlled trials suggest the use of statins for the prevention of albuminuria and renal function impairment in CKD and DKD patients. However, a large clinical study, the Study of Heart and Renal Protection (SHARP), does not support that statins could reduce ESRD in CKD. In this article, we analyze the complex association of dyslipoproteinemia with DKD and deduce its relevance from animal studies, observational studies, and clinical trials. We show that special subgroups could benefit from the statin treatment.

Pharmacologic management of chronic reno-cardiac syndrome

Chronic kidney disease (CKD) significantly increases cardiovascular morbidity and mortality. CKD remains an under-represented population in cardiovascular clinical trials, and cardiovascular disease is an under-treated entity in CKD. Traditional cardiovascular risk factors in conjunction with uremia-related complications often progress to myocardial dysfunction. Such uremic cardiomyopathy leads to over-activation of neurohormonal pathways with detrimental effects. Management of the reno-cardiac syndrome (RCS) requires the targeting of these multiple facets. In this article we discuss the relevant pathophysiology of RCS, and present the clinical data related to its management.

Dynamic and dual effects of glycated hemoglobin on estimated glomerular filtration rate in type 2 diabetic outpatients

BACKGROUND

Diabetic nephropathy is the leading cause of incident end-stage renal disease in Taiwan. Previous studies on the consistent benefits of glycemic control in diabetic nephropathy focused primarily on delaying microalbuminuria. However, this effect on glomerular filtration rate (GFR) remains controversial. This study aims to establish a model that explains the controversial effects of glycated hemoglobin (HbA1C) on GFR.

METHODS

This retrospective cohort study followed subjects with type 2 diabetes mellitus, who were enrolled between June 2006 and December 2006, for 4 years. The effects of HbA1C on estimated GFR (eGFR) were examined both cross-sectionally and longitudinally. The dual effects of HbA1C on eGFR, and how renal function interferes with these effects, were investigated.

RESULTS

Of the 1,992 subjects enrolled, 1,699 completed the follow-up. HbA1C was positively correlated with eGFR in the cross-sectional study (β coefficient = 1.44, 95% CI: 0.71-2.17, p = 0.0001). In the longitudinal study, higher baseline HbA1C resulted in a greater decline in eGFR. The annual eGFR decline rates were -1.89, -1.29, and -0.68 ml/min/1.73 m(2)/year for baseline HbA1C >9, 7 to ≤9, and ≤7%, respectively. The eGFR value was simultaneously affected by concurrent (β coefficient = 0.78, 95% CI: 0.48-1.08, p < 0.0001) and preceding HbA1C (-0.52, -0.82 to -0.23, p < 0.0001). The positive effects of concurrent HbA1C on eGFR reached statistical significance at all stages of chronic kidney disease (CKD); however, the negative effects of preceding HbA1C only applied to CKD stages 3 and 4.

CONCLUSIONS

We developed a new model that demonstrates how preceding and concurrent HbA1C simultaneously affect eGFR in opposing ways. The dynamic effects varied among different CKD stages. The deterioration in eGFR at CKD stages 3 and 4 may be postponed by intensive glycemic control. Further prospective studies may be necessary to clarify the specific CKD stage(s) that will benefit from intensive glycemic control.

Delayed progression to dialysis with early and intensive management of predialysis chronic kidney disease: a case-based approach

In addition to hypertension and diabetes, disorders in mineral metabolism and bone disease (e.g. affecting phosphorus, calcium, parathyroid hormone, and vitamin D) are common complications of chronic kidney disease (CKD) and contribute to morbidity and mortality. Consequently, CKD requires multifactorial treatment to slow CKD progression and avoid end-stage renal disease. CKD progression and treatment outcomes are monitored by measuring the estimated glomerular filtration rate (eGFR), which decreases by 2–12 ml/min/1.73 m² per year depending on the stage of CKD and comorbidities, such as diabetes. This paper presents representative case studies illustrating the delay and reversal of CKD progression with comprehensive, individualized treatment regimens, including non-calcium phosphate binders, antihypertensives, lipid-lowering drugs, calcimimetics, and other drugs as required, to treat each component of CKD including CKD-mineral and bone disorder. Four patients are included, with an average age of 70–81 years and CKD stage 3 or 4 accompanied by various comorbidities, most notably diabetes and hypertension. The range of treatment and follow-up durations was 6–7 years. In each case, there was evidence of slowing or prevention of CKD progression, according to eGFR and serum creatinine, regardless of the patient's age or CKD stage. Despite a baseline eGFR of <20 ml/min/1.73 m² in 1 female patient, after 6 years of follow-up, her eGFR had stabilized and was maintained at >15 ml/min/1.73 m². These observations reinforce the value of early nephrology referral and comprehensive management of CKD and underlying conditions (hypertension and diabetes) beginning at eGFR <60 ml/min/1.73 m².

Atorvastatin ameliorates podocyte injury in patients with type 2 diabetes complicated with dyslipidemia

We examined the effects of atorvastatin on urinary podocyte excretion. Thirteen patients with type 2 diabetes receiving 2.5mg of rosuvastatin were recruited and the medication was switched to 10mg of atorvastatin for a 24-week period. With the switch to atorvastatin, the urinary excretion of podocytes was significantly reduced.

Triglyceride-cholesterol imbalance across lipoprotein subclasses predicts diabetic kidney disease and mortality in type 1 diabetes: the FinnDiane Study

BACKGROUND

Circulating cholesterol (C) and triglyceride (TG) levels are associated with vascular injury in type 1 diabetes (T1DM). Lipoproteins are responsible for transporting lipids, and alterations in their subclass distributions may partly explain the increased mortality in individuals with T1DM.

DESIGN AND SUBJECTS

A cohort of 3544 individuals with T1DM was recruited by the nationwide multicentre FinnDiane Study Group. At baseline, six very low-density lipoprotein VLDL, one intermediate-density lipoprotein IDL, three low-density lipoprotein LDL and four higher high-density lipoprotein HDL subclasses were quantified by proton nuclear magnetic resonance spectroscopy. At follow-up, the baseline data were analysed for incident micro- or macroalbuminuria (117 cases in 5.3 years), progression from microalbuminuria (63 cases in 6.1 years), progression from macroalbuminuria (109 cases in 5.9 years) and mortality (385 deaths in 9.4 years). Univariate associations were tested by age-matched cases and controls and multivariate lipoprotein profiles were analysed using the self-organizing map (SOM).

RESULTS

TG and C levels in large VLDL were associated with incident albuminuria, TG and C in medium VLDL were associated with progression from microalbuminuria, and TG and C in all VLDL subclasses were associated with mortality. Large HDL-C was inversely associated with mortality. Three extreme phenotypes emerged from SOM analysis: (i) low C (<3% mortality), (ii) low TG/C ratio (6% mortality), and (iii) high TG/C ratio (40% mortality) in all subclasses.

CONCLUSIONS

TG-C imbalance is a general lipoprotein characteristic in individuals with T1DM and high vascular disease risk.

Statin use in patients with diabetes and kidney disease: the Japanese experience

Diabetes is a leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in developed nations, including Japan and the United States. Japan has the unenviable distinction of having one of the world's highest rates of dialysis: in 2011, there were over 300,000 dialysis patients (2,383 per million people), with diabetic patients accounting for almost half of all incident cases. Concomitance of CKD and diabetes predicts a greater risk of cardiovascular disease (CVD) than either condition in isolation. Hence, appropriate management of modifiable cardiovascular (CV) risk factors, including dyslipidemia, is paramount in this high-risk group. The United States and Japan have distinct approaches to cholesterol management, with more stringent therapeutic targets for lipid control advocated in US guidelines. However, upward trends in cholesterol levels and coronary heart disease incidence in Japan may provide justification for more intensive CV risk factor management strategies by Japanese physicians to achieve maximum benefit. Attainment of recommended lipid goals in Japan is poor, particularly in patients with diabetes and/or CKD in whom CV risk factors are often undertreated. Statin therapy has been shown to be safe and effective in reducing CV risk in patients with diabetes and/or CKD stages 1-5. Moreover, statins may impart a renoprotective effect by preventing or delaying progressive loss of kidney function. This review summarizes evidence from studies in Western and Japanese populations to highlight the CV and renal benefits of lipid-lowering agents in CKD patients, including those with diabetes.

Targets, trends, excesses, and deficiencies: refocusing clinical investigation to improve patient outcomes

Clinical trials in nephrology have focused on achieving targets, supplementing deficiencies, and correcting excesses in order to improve patient outcomes. The majority of interventions have failed to demonstrate benefit and some have caused harm. It may be that therapies aiming to 'normalize' parameters may actually disturb evolutionary adaptation, thus causing harm. By refocusing on the physiology of disease, and complexity of adaptation, we may design better trials. We review successful and unsuccessful trials in nephrology and other disciplines and suggest a set of principles by which to design future clinical trials:(1) acknowledge heterogeneity of chronic kidney disease populations and appropriately characterize populations for studies; (2) develop better validated biomarkers (through proteomics, genomics, and metabolomics) to identify responders and nonresponders to interventions; (3) design interventions that mimic physiological processes without collateral detrimental effects; (4) reconsider the status of the randomized-controlled trial as the only 'gold standard' and perform large-scale pragmatic trials comparing current care with the intervention(s) of interest, and (5) broaden nephrology research culture so that the majority of patients are enrolled into observational cohorts and intervention studies, which foster greater knowledge acquisition and dissemination. Improved understanding of pathophysiological mechanisms, in conjunction with more innovative but stringent clinical trial design, will ultimately lead to improved patient outcomes.

Prevalence and control of dyslipidaemia among diabetic patients with microalbuminuria in a Chinese hospital

BACKGROUND

Accumulating evidence indicates that dyslipidaemia plays an important role in the progression of kidney disease in patients with diabetes. Hyperlipidaemia is a risk factor for microalbuminuria in patients with diabetes. Little information exists on the prevalence and control of dyslipidaemia among diabetic patients with microalbuminuria in China. The aims of this study were to investigate the prevalence and control of dyslipidaemia among diabetic patients with microalbuminuria in a Chinese hospital as well as factors affecting the disease.

METHODS

A total of 1060 type 2 diabetic inpatients were assigned to the with-microalbuminuria group (n = 635) or the without-microalbuminuria group on the basis of urinary albumin-to-creatinine ratios (UACRs = 30-299 mg/g). Serum levels and the control of lipid profiles were assessed and classified according to the 2011 American Diabetes Association (ADA) guidelines, and low-density lipoprotein-cholesterol (LDL-C) was also assessed and classified according to Chinese intensified control criteria. Multiple regression analyses were performed to examine the factors affecting lipid variables.

RESULTS

Among patients with microalbuminuria, a significantly lower prevalence was found (33.1% vs. 58.6%; 35.3% vs. 52.5%, all p < 0.001) at target levels [LDL-C < 2.60 mmol/L or high-density lipoprotein-cholesterol (HDL-C) > 1.0 mmol/L for men and >1.3 mmol/L for women]. According to the intensified LDL-C goal (<2.07 mmol/L), a lower prevalence was found in male patients (15.5% vs. 32.7%, p < 0.001). Fewer patients with microalbuminuria were adherent to the therapy prescribed for dyslipidaemia (28.8% vs. 43.3%, p < 0.001). Even among patients who were on lipid-lowering treatment, the majority of individuals remained uncontrolled for all three lipid fractions [LDL-C, HDL-C and triglyceride (TG)] (82.5% vs. 69.0%, p = 0.003). Lipid and lipoprotein parameters were associated with gender and age.

CONCLUSION

In China, diabetic patients with microalbuminuria displayed typical dyslipidaemias and were not adequately controlled. Intensified LDL-C and overall lipid-lowering clinical goals are potential precautions taken against diabetic nephropathy.

Association of dyslipidemia with renal outcomes in chronic kidney disease

Dyslipidemia is highly prevalent in patients with chronic kidney disease (CKD) and the relationship between dyslipidemia with renal outcomes in patients with moderate to advanced CKD remains controversial. Hence, our objective is to determine whether dyslipidemia is independently associated with rapid renal progression and progression to renal replacement therapy (RRT) in CKD patients. The study analyzed the association between lipid profile, RRT, and rapid renal progression (estimated glomerular filtration rate [eGFR] slope <-6 ml/min/1.73 m(2)/yr) in 3303 patients with stages 3 to 5 CKD. During a median 2.8-year follow-up, 1080 (32.3%) participants commenced RRT and 841 (25.5%) had rapid renal progression. In the adjusted models, the lowest quintile (hazard ratios [HR], 1.23; 95% confidence interval [CI], 1.01 to 1.49) and the highest two quintiles of total cholesterol (HR, 1.25; 95% CI, 1.02 to 1.52 and HR, 1.35; 95% CI, 1.11 to 1.65 respectively) increased risks for RRT (vs. quintile 2). Besides, the highest quintile of total cholesterol was independently associated with rapid renal progression (odds ratio, 1.36; 95% CI, 1.01 to 1.83). Our study demonstrated that certain levels of dyslipidemia were independently associated with RRT and rapid renal progression in CKD stage 3-5. Assessment of lipid profile may help identify high risk groups with adverse renal outcomes.

Reasons for the lack of salutary effects of cholesterol-lowering interventions in end-stage renal disease populations

Cardiovascular disease (CVD) is the main cause of premature death in patients with chronic kidney disease (CKD). The underlying mechanisms of CVD in patients with mild to moderate CKD are different from those with end-stage renal disease (ESRD). While serum cholesterol is frequently elevated and contributes to atherosclerosis in many CKD patients, particularly those with nephrotic proteinuria, it is usually normal, even subnormal, in most ESRD patients receiving hemodialysis. CVD in the ESRD population is primarily driven by oxidative stress, inflammation, accumulation of the oxidation-prone intermediate-density lipoproteins, chylomicron remnants and small dense low-density lipoprotein particles as well as high-density lipoprotein deficiency and dysfunction, hypertension, vascular calcification, and arrhythmias. Only a minority of hemodialysis patients have hypercholesterolemia which is most likely due to genetic or unrelated factors. In addition, due to peritoneal losses of proteins which simulate nephrotic syndrome, peritoneal dialysis patients often exhibit hypercholesterolemia. Clearly when present, hypercholesterolemia contributes to CVD in the CKD and ESRD population and justifies cholesterol-lowering therapy. However, the majority of ESRD patients and a subpopulation of CKD patients with minimal proteinuria have normal or subnormal serum cholesterol levels and do not benefit from and can be potentially harmed by statin therapy. In fact the lack of efficacy of statins in hemodialysis patients has been demonstrated in several randomized clinical trials. This review is intended to provide an overview of the mechanisms responsible for the failure of statins to reduce cardiovascular morbidity and mortality in most ESRD patients and to advocate the adoption of individualized care principles in the management of dyslipidemia in this population.