Statins for improving renal outcomes: a meta-analysis

Complications and characteristics of patients referred to a joint diabetes renal clinic in Ireland

BACKGROUND AND METHODS

Joint diabetes renal (JDR) clinics are recommended as the appropriate model of care to manage advanced diabetic-associated renal failure. We performed a retrospective review of clinical data and records of the first 60 patients who attended our service and their follow-up at 12 months.

RESULTS

Of the patients, 88 % had type 2 diabetes. At the first visit, 43 % had retinopathy, 56 % had neuropathy, 48 % had overt cardiovascular disease, 13 % had a previous history of stroke and 36 % peripheral arterial disease. Ten percent had lower limb amputation and 33 % had never previously seen a diabetologist. Fifteen percent were still on metformin despite significant renal impairment, while 43 % were on three or more different antihypertensives. Sixty-eight percent were either on an ACE inhibitor or angiotensin receptor blocker. At 12 months, a trend towards a reduction in HbA1c (7.6 ± 2.0 vs. 7.0 ± 1.6 %, p = 0.14) and systolic (159.4 ± 30.8 vs. 141.8 ± 35.5 mmHg, p = 0.13) and diastolic blood pressure (73.2 ± 9.3 vs. 69.2 ± 9.4 mmHg, p = 0.075) was observed. No significant differences were found in the lipid profile or creatinine clearance within the group.

CONCLUSION

Thirty-three percent of patients with advanced diabetic nephropathy had never previously seen a diabetes consultant and a significant proportion had other diabetes-related complications. Patients with diabetic nephropathy may therefore benefit from having a multidisciplinary input at a joint diabetes renal clinic.

Cis-vaccenic acid and the Framingham risk score predict chronic kidney disease: the multi-ethnic study of atherosclerosis (MESA)

INTRODUCTION

Data on the associations of fatty acids with chronic kidney disease (CKD) are sparse.

MATERIALS AND METHODS

We performed a cross-sectional study of 2792 men and women from the MESA cohort of African-American, Caucasian, Chinese and Hispanic adults without known cardiovascular disease. Plasma phospholipid fatty acid proportions were associated with estimated glomerular filtration rate (eGFR) and the albumin/creatinine ratio.

RESULTS

Cis-vaccenic acid (18:1n-7), adjusted for other fatty acids using multivariate logistic regression (CI: 1.0-1.4), and step-wise logistic regression (CI: 1.02-1.42), was positively associated with reduced eGFR. The Framingham Risk Score, when adjusting for fatty acid proportions and demographic factors, was positively associated with CKD as measured by the eGFR and the albumin/creatinine ratio.

DISCUSSION AND CONCLUSIONS

Plasma phospholipid proportions of the 18 carbon monounsaturated cis-vaccenic acid {18:1n-7}) and the Framingham Risk Score are associated with kidney function. The potential role of 18:1n-7 in the development of CKD warrants further investigation.

Effects of lipid-lowering therapy with rosuvastatin on kidney function and oxidative stress in patients with diabetic nephropathy

AIM

We aimed to assess the effects of rosuvastatin treatment on lipid levels, a biomarker of oxidative stress, albuminuria, and kidney function in patients with diabetic nephropathy.

METHODS

We conducted a prospective, open-label, parallel group, controlled study of 104 patients with diabetic nephropathy, low-density lipoprotein cholesterol (LDL-C) levels of > 120 mg/dL, and well-controlled blood pressure who were undergoing treatment with renin angiotensin system inhibitors. Patients were randomly assigned to two groups: the rosuvastatin group (n = 52; 2.5 mg/day rosuvastatin, increased to 10 mg/day) and the control group (n = 52; no rosuvastatin administered). We determined the efficacy of rosuvastatin by monitoring serum lipid profiles, high sensitivity C-reactive protein (hs-CRP), malondialdehyde-modified LDL (MDA-LDL), and cystatin C levels. In addition, urinary albumin, 8-hydroxydeoxyguanosine (8-OHdG) and liver-type fatty acid-binding protein (L-FABP) levels were measured before and 6 months after rosuvastatin was added to the treatment.

RESULTS

Rosuvastatin effectively reduced total cholesterol, LDL-C, triglycerides, non-high-density lipoprotein cholesterol (non-HDL-C) levels, and the LDL-C/ HDL-C ratio in the rosuvastatin group. These parameters remained unchanged in patients who were not treated with rosuvastatin. Although there was no significant change in the estimated glomerular filtration rate level, serum cystatin C levels and urinary albumin excretion rates were significantly decreased in the rosuvastatin group. In addition, rosuvastatin significantly reduced hs-CRP and MDA-LDL levels. Moreover, urinary 8-OHdG and L-FABP levels at baseline (13.5±5.1 and 41.7±26.1 ng/mgCr, respectively) decreased significantly at 6 months (11.5±4.0 and 26.9±13.4 ng/mgCr, respectively), and there was a significant correlation (r = 0.48, p < 0.01). Multivariate analysis revealed that albuminuria was significantly correlated with only rosuvastatin use (p = 0.0006, R(2)= 0.53).

CONCLUSION

Rosuvastatin administration reduced albuminuria, oxidative stress, and serum cystatin C levels, independent of blood pressure and lipid levels.

Proteinuria should be used as a surrogate in CKD

Surrogate end points of renal failure are instrumental to the testing of new treatments in patients with chronic kidney disease, the natural history of which is characterized by a slow, asymptomatic decline in renal function. The magnitude of proteinuria is widely recognized as a marker of the severity of glomerulopathy. Population-based studies have identified proteinuria as a predictor of future decline in glomerular filtration rate and of the development of end-stage renal disease. More importantly, a reduction in proteinuria invariably translates into a protection from renal function decline in patients with diabetic and nondiabetic renal disease with overt proteinuria. Thus, proteinuria should be considered a valuable surrogate end point for clinical trials in patients with proteinuric renal diseases.

Dyslipidemia in children with CKD: should we treat with statins?

Dyslipidemia has been shown to be a risk factor for increased cardiovascular morbidity and mortality in adult patients with chronic kidney disease (CKD) stages 2-4. In patients on dialysis, a paradoxical correlation has been found between low cholesterol values and increased mortality rates. No data exist in children. Treatment with statins has been convincingly shown to both reduce blood lipid levels and mortality rates from cardiovascular disease in adult patients in CKD stages 2-4. There is no strong literature support for treating patients on dialysis or after having had a transplant. Data on benefits of statin therapy do not exist in children with CKD. There are many differences between adult and paediatric kidney patients, and I caution on extrapolating the findings in adult patients to children. Studies are thus needed to evaluate the benefits and potential problems of statin treatment in children with CKD.

Ezetimibe alone or in combination with pitavastatin prevents kidney dysfunction in 5/6 nephrectomized rats fed high-cholesterol

We attempted to elucidate the relationship between cholesterol absorption and kidney damage by investigating the renoprotective effect of ezetimibe, a cholesterol absorption inhibitor, in 5/6 nephrectomized rats (Nx). The Nx or sham-operated rats (Sham) were fed 1% high-cholesterol diet (HC) containing ezetimibe (10 mg/[kg d]), pitavastatin (3 mg/[kg d]), or both for 8 weeks. Pathological changes, endothelial nitric oxide synthase (eNOS) messenger RNA (mRNA), and oxidative stress were assessed in the kidney. The Sham fed HC exhibited hypercholesterolemia and glomerulosclerosis with macrophage infiltration in the kidney, and ezetimibe attenuated these changes. The Nx exhibited hypercholesterolemia, increased urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), glomerulosclerosis with macrophage infiltration and interstitial fibrosis, and downregulation of eNOS mRNA. The HC increased cholesterol further and worsened the kidney damage with increased 8-OHdG. Ezetimibe attenuated the hypercholesterolemia, kidney dysfunction, and pathological changes. The beneficial effects of ezetimibe were significantly associated with reduced 8-OHdG (P < .01). Pitavastatin did not reduce cholesterol or 8-OHdG, but it did significantly suppress the kidney damage with upregulated eNOS mRNA by 2.5-fold (P < .02). The combination of ezetimibe and pitavastatin synergistically ameliorated the kidney damage. The kidney dysfunction and pathological changes were significantly associated with cholesterol, markers of cholesterol absorption (campesterol and cholestanol), and 8-OHdG (P < .001-.05). Multiple regression analysis revealed that the markers of cholesterol absorption were independently associated with the kidney damage. Ezetimibe confers renoprotective effects by inhibiting cholesterol absorption, which in turn reduces oxidative stress; and pitavastatin additively ameliorates kidney damage by increasing NO production via mechanisms independent of cholesterol reduction.

Statin use and the presence of microalbuminuria. Results from the ERICABEL trial: a non-interventional epidemiological cohort study

BACKGROUND

Microalbuminuria (MAU) is considered as a predictor or marker of cardiovascular and renal events. Statins are widely prescribed to reduce cardiovascular risk and to slow down progression of kidney disease. But statins may also generate tubular MAU. The current observational study evaluated the impact of statin use on the interpretation of MAU as a predictor or marker of cardiovascular or renal disease.

METHODOLOGY/PRINCIPAL FINDINGS

We used cross-sectional data of ERICABEL, a cohort with 1,076 hypertensive patients. MAU was defined as albuminuria ≥20 mg/l. A propensity score was created to correct for "bias by indication" to receive a statin. As expected, subjects using statins vs. no statins had more cardiovascular risk factors, pointing to bias by indication. Statin users were more likely to have MAU (OR: 2.01, 95%CI: 1.34-3.01). The association between statin use and MAU remained significant after adjusting for the propensity to receive a statin based on cardiovascular risk factors (OR: 1.82, 95%CI: 1.14-2.91). Next to statin use, only diabetes (OR: 1.92, 95%CI: 1.00-3.66) and smoking (OR: 1.49, 95%CI: 0.99-2.26) were associated with MAU.

CONCLUSIONS

Use of statins is independently associated with MAU, even after adjusting for bias by indication to receive a statin. In the hypothesis that this MAU is of tubular origin, statin use can result in incorrect labeling of subjects as having a predictor or marker of cardiovascular or renal risk. In addition, statin use affected the association of established cardiovascular risk factors with MAU, blurring the interpretation of multivariable analyses.

Beneficial effect of atorvastatin on renal function in patients with type 2 diabetes

Two studies investigated the effect of atorvastatin on glycaemic control and renal function in patients with type 2 diabetes. In study 1, 27 outpatients with hypercholesterolaemia (16 statin-naïve, 11 switched from another statin) took atorvastatin (10 mg once daily) for 3 months. After 3 months, low-density lipoprotein cholesterol (LDL-C) had decreased significantly in both groups, high-density lipoprotein cholesterol (HDL-C) and estimated glomerular filtration rate had increased only in the statin-naïve group, and glycosylated haemoglobin (HbA(1c)) had not changed significantly in either group. Study 2 was a retrospective investigation of 87 outpatients with hyper cholesterolaemia who had been taking atorvastatin for at least 4 years. Compared with baseline (patients who had taken atorvastatin for at least 1 year), total cholesterol and triglyceride levels did not change over the study period, HDL-C increased significantly at 2 and 3 years, HbA(1c) was significantly decreased at 1, 2 and 3 years and serum creatinine was significantly decreased at 1 year. Atorvastatin lowered LDL-C concentration, did not worsen glycaemic control and might improve renal function in patients with type 2 diabetes.

Triglyceride-high-density lipoprotein cholesterol is associated with microvascular complications in type 2 diabetes mellitus

The purpose of this study was to evaluate whether a high triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio is associated with an increased incidence of retinopathy and chronic kidney disease (CKD) in type 2 diabetes mellitus. Individuals with type 2 diabetes mellitus (n = 979) with an estimated glomerular filtration rate greater than 60 mL/min and without retinopathy and cardiovascular disease at baseline were followed up for the incidence of diabetic retinopathy (diagnosed by retinography) and CKD (diagnosed by estimated glomerular filtration rate ≤60 mL/min/1.73 m(2)). On follow-up (mean, 4.9 years), 217 (22.2% of total) subjects experienced CKD and/or diabetic-specific retinal lesions (microvascular complication). Of these, 111 subjects developed isolated retinopathy, 85 developed CKD alone, and 21 developed both complications. The TG/HDL-C ratio was positively associated with an increased risk of incident retinopathy and/or CKD (composite microvascular end point) independently of age, sex, body mass index, diabetes duration, hemoglobin A(1c), hypertension, smoking history, low-density lipoprotein cholesterol, albuminuria, and current use of hypoglycemic, antihypertensive, lipid-lowering, or antiplatelet drugs (multivariable-adjusted odds ratio, 2.15; 95% confidence intervals, 1.10-4.25; P = .04). These findings suggested that the TG/HDL-C ratio was associated with an increased incidence of microvascular complications in individuals with type 2 diabetes mellitus without prior cardiovascular disease, independently of several potential confounders.

IMproving the imPlemEntation of cuRrent guidelines for the mAnagement of major coronary hearT disease rIsk factors by multifactorial interVEntion. The IMPERATIVE renal analysis

INTRODUCTION

The short-term effects of multifactorial intervention for cardiovascular disease (CVD) prevention on renal function and serum uric acid (SUA) levels in patients with stage 3 chronic kidney disease (CKD) and multiple CVD risk factors are unclear. The aim of the study was to prospectively assess these effects.

MATERIAL AND METHODS

This post hoc analysis of 5 "best practice" studies involved patients with multiple CVD risk factors. Estimated glomerular filtration rate (eGFR) was assessed using the Modification of Diet in Renal Disease (MDRD) formula. Among the 4,153 patients, 1,235 (29.7%) had stage 3 CKD (eGFR between 30 and 59 ml/min/1.73 m(2)). A baseline visit was followed by a concerted effort from previously trained physicians to improve adherence to lifestyle advice and optimize drug treatment, including a statin, for all vascular risk factors. After 6 months eGFR and SUA levels were re-evaluated.

RESULTS

The intervention improved compliance to lifestyle measures and increased the use of evidence-based medication, including a statin. There was also a 5.6% increase in eGFR (p < 0.001) in patients with stage 3 CKD and a 6.1% reduction in SUA levels (p < 0.001). Among patients with stage 3 CKD, 127 (10.3%) improved to stage 2 CKD and 9 (0.7%) advanced to stage 4 CKD by the end of the 6-month study period. There were no major side-effects.

CONCLUSIONS

Multitargeted intervention, including a statin, may improve renal function and reduce SUA levels within 6 months, thus offsetting 2 potential CVD risk factors in high-risk patients.

Chronic kidney disease, dyslipidemia, and atherosclerosis

Patients with chronic kidney disease (CKD) are at an increased risk not only for end-stage kidney disease (ESKD) but also for cardiovascular disease (CVD). In this review article, we summarize the current evidence of CKD as a high-risk condition for CVD based on reports from Japan and other countries to draw attention to the close clinical association between CKD and CVD. Several epidemiologic studies have shown that the presence of CKD and reduced renal function are independent predictors of CVD also in Japan. According to a post-hoc analysis of CASE-J, the power of CKD as a predictor of CVD is as strong as diabetes mellitus and a previous history of ischemic heart disease. CKD worsens classical risk factors including hypertension and dyslipidemia, and dyslipidemia is associated with increased thickness and stiffness of large arteries independent of major confounders. A post-hoc analysis of MEGA indicates that lipid-lowering therapy with statins reduces the risk of CVD, and that it appears to be more efficacious in patients with than without CKD. These reports from Japan and other countries suggest that CKD should be regarded as a high-risk condition comparable to diabetes mellitus, and that strict control of dyslipidemia would be beneficial in preventing CVD, at least early stages of CKD.

Treatment of chronic kidney disease

Treatment of chronic kidney disease (CKD) can slow its progression to end-stage renal disease (ESRD). However, the therapies remain limited. Blood pressure control using angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) has the greatest weight of evidence. Glycemic control in diabetes seems likely to retard progression. Several metabolic disturbances of CKD may prove to be useful therapeutic targets but have been insufficiently tested. These include acidosis, hyperphosphatemia, and vitamin D deficiency. Drugs aimed at other potentially damaging systems and processes, including endothelin, fibrosis, oxidation, and advanced glycation end products, are at various stages of development. In addition to the paucity of proven effective therapies, the incomplete application of existing treatments, the education of patients about their disease, and the transition to ESRD care remain major practical barriers to better outcomes.

Effects of atorvastatin on progression of diabetic nephropathy and local RAGE and soluble RAGE expressions in rats

OBJECTIVE

Advanced glycation end-products (AGEs) exert inflammatory and oxidative stress insults to produce diabetic nephropathy mainly through the receptor for AGEs (RAGE). This study aimed to assess the effect of atorvastatin on diabetic nephropathy via soluble RAGE (sRAGE) and RAGE expressions in the rat kidney.

METHODS

Thirty-two male Sprague-Dawley rats were divided into four groups based on the presence or absence of streptozotocin-induced diabetes with or without atorvastatin treatment (10 mg/kg for 24 weeks). Serum sRAGE and glycated albumin (GA) levels were measured with enzyme-linked immunosorbent assay (ELISA) and improved bromocresol purple methods. Renal AGEs, RAGE, endogenous secretory RAGE (esRAGE), and sRAGE were determined with reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.

RESULTS

Mesangial expansion and microalbuminuria were aggravated in diabetic rats, and improved with atorvastatin treatment. Serum sRAGE levels were lower in diabetic than in normal rats. After atorvastatin treatment, serum and renal sRAGE levels were up-regulated, while renal RAGE expression was decreased in diabetic rats, associated with a reduction in accumulation of AGEs, though renal esRAGE mRNA expression was not significantly increased.

CONCLUSIONS

Atorvastatin exerted a beneficial effect on diabetic nephropathy with reduced AGE accumulation, down-regulating RAGE expression and up-regulating sRAGE in the kidney.

Cardiovascular risk management in chronic kidney disease in general practice (the AusHEART study)

BACKGROUND

Chronic kidney disease (CKD) is common and increasing in prevalence. Adverse outcomes of CKD can be prevented through early detection and treatment. There is limited data on the awareness of CKD and the quality of care offered to patients with CKD in the primary care setting. The objectives of this study were to assess the prevalence, general practitioner (GP) awareness and extent of current evidence-practice gaps in the management of CKD in Australian primary care.

METHODS

The Australian Hypertension and Absolute Risk Study (AusHEART) was a nationally representative, cluster stratified, cross-sectional survey among 322 GPs. Each GP was asked to provide data for 15-20 consecutive patients (age ≥ 55 years) who presented between April and June, 2008. The main outcome measures were CKD prevalence based on proteinuria and decreased estimated glomerular filtration rate. Evidence-practice gaps in management of patients with CKD were identified.

RESULTS

Among a total of 4966 patients with kidney function test data, 1845 (37%) had abnormal kidney function. Of the 1312 patients with abnormal kidney function known to the GP at the time of visit, only 235 were correctly identified as having CKD. GPs under-estimated cardiovascular (CV) risks in patients with CKD when compared with the prevailing guidelines at the time of survey and the recent national guidelines, particularly in later stages of CKD. Among CKD patients not prescribed blood pressure-lowering agents or lipid-lowering agents, treatment was indicated as per relevant guidelines in 51 and 46%, respectively. For CKD patients who were already prescribed blood pressure-lowering and lipid-lowering agents, 61 and 50%, respectively, did not meet the treatment targets recommended by the relevant guidelines.

CONCLUSIONS

CKD is common, significantly under-recognized and under-treated in primary care. Effort to increase awareness and provide opportunities for improved screening and assessment should improve the management and outcome of these patients at high risk of CV disease.

Efficacy and safety of pitavastatin in Japanese patients with hypercholesterolemia: LIVES study and subanalysis

The Livalo Effectiveness and Safety (LIVES) study was an observational study to examine the efficacy and safety of pitavastatin, a newly developed drug, in approximately 20,000 Japanese patients with hypercholesterolemia. During a 2-year follow-up period, no significant problems concerning safety were observed upon treatment with pitavastatin. Pitavastatin demonstrated potent and stable lowering of the LDL-cholesterol level. The LIVES study subanalyses revealed significant and continuous elevation of HDL-cholesterol in association with pitavastatin treatment and also showed that the drug did not adversely affect glycemic control as evaluated by the glycohemoglobin A(1c) level. Moreover, pitavastatin treatment was associated with an increase in estimated glomerular filtration rate in subjects with chronic kidney disease. These results suggest the usefulness of pitavastatin in hypercholesterolemic patients from various backgrounds. The ongoing LIVES study extension is expected to provide further data on cardiovascular outcome in subjects treated with pitavastatin.

Socioeconomic status and reduced kidney function in the Whitehall II Study: role of obesity and metabolic syndrome

BACKGROUND

Previous US-based studies have found that chronic kidney disease (CKD) disproportionately affects those of more adverse social circumstances. Our aim was to show the association between socioeconomic status (SES) and decreased kidney function in a European context and explore the role of obesity and metabolic syndrome. We consider the potential confounding effect of lean muscle mass.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

White participants in the follow-up of the Whitehall II cohort: UK-based European population (age, 55-79 years; n = 5,533), of whom 4,066 men (73%) and 1,467 women (27%) with complete data were analyzed.

PREDICTORS

Self-reported occupational grade/salary range.

OUTCOMES

Estimated glomerular filtration rate (GFR) using the CKD-EPI (CKD Epidemiology Collaboration) equation.

MEASUREMENTS

Body mass index (BMI), serum lipid levels, blood pressure, Tanita TBF-300 body composition analyzer, impedance-derived lean mass index (LMI).

RESULTS

Participants in a lower compared with higher occupational grade were at increased odds of having decreased GFR (age- and sex-adjusted OR, 1.31; 95% CI, 1.12-1.53; P = 0.001). Socioeconomic disparity in LMI was evident in women, but not men. After further adjustment for BMI and components of metabolic syndrome, the odds of decreased GFR in whites with a lower compared with higher occupational grade was attenuated by 23.3% (OR, 1.23; 95% CI, 1.06-1.45; P = 0.008). Adjustment for LMI explained 15% of the association between SES and estimated GFR.

LIMITATIONS

Cross-sectional design, missing data for subset of participants, no urinary data.

CONCLUSIONS

BMI and components of metabolic syndrome may explain up to a quarter of the association between low SES and decreased GFR, suggesting potential modifiable factors.

Renal oxidative stress, oxygenation, and hypertension

Hypertension is closely associated with progressive kidney dysfunction, manifested as glomerulosclerosis, interstitial fibrosis, proteinuria, and eventually declining glomerular filtration. The postulated mechanism for development of glomerulosclerosis is barotrauma caused by increased capillary pressure, but the reason for development of interstitial fibrosis and the subsequently reduced kidney function is less clear. However, it has been hypothesized that tissue hypoxia induces fibrogenesis and progressive renal failure. This is very interesting, since recent reports highlight several different mechanisms resulting in altered oxygen handling and availability in the hypertensive kidney. Such mechanisms include decreased renal blood flow due to increased vascular tone induced by ANG II that limits oxygen delivery and increases oxidative stress, resulting in increased mitochondrial oxygen usage, increased oxygen usage for tubular electrolyte transport, and shunting of oxygen from arterial to venous blood in preglomerular vessels. It has been shown in several studies that interventions to prevent oxidative stress and to restore kidney tissue oxygenation prevent progression of kidney dysfunction. Furthermore, inhibition of ANG II activity, by either blocking ANG II type 1 receptors or angiotensin-converting enzyme, or by preventing oxidative stress by administration of antioxidants also results in improved blood pressure control. Therefore, it seems likely that tissue hypoxia in the hypertensive kidney contributes to progression of kidney damage, and perhaps also persistence the high blood pressure.

Association between the changes in renal function and serum uric acid levels during multifactorial intervention and clinical outcome in patients with metabolic syndrome. A post hoc analysis of the ATTEMPT study

AIM

To assess the effects of long-term multifactorial intervention on renal function and serum uric acid (SUA) levels and their association with estimated cardiovascular disease (eCVD) risk and actual CVD events.

METHODS

This prospective, randomized, target-driven study included 1123 subjects (45.6% men, age 45-65 years) with metabolic syndrome (MetS) but without diabetes or CVD. Patients were randomized to multifactorial treatment. Atorvastatin was titrated from 10-80 mg/day aiming at a low density lipoprotein cholesterol (LDL-C) target of <100 mg/dl (group A) or an LDL-C target of <130 mg/dl (group B). Changes in estimated glomerular filtration rate (eGFR) and SUA levels were recorded in all patients and in the subgroup with stage 3 chronic kidney disease (CKD; eGFR = 30-59 ml/min/1.73 m(2); n = 349). We used ANOVA to compare changes within the same group, unpaired Student t-test to compare results between groups at specific time points, and log-rank test to compare event free survival.

RESULTS

The eCVD-risk reduction was greater in group A. In the overall study population, eGFR increased by 3.5% (p < 0.001) and SUA levels fell by 5.6% (p < 0.001). In patients from group A with stage 3 CKD (group A1; n = 172), eGFR increased by 11.1% (p < 0.001) from baseline and by 7.5% (p < 0.001) in group B1 (n = 177; p < 0.001 vs. the change in group A1). The corresponding fall in SUA levels was 10.7% in group A1 (p < 0.001 vs. baseline) and 8.3% in group B1 (p < 0.001 vs. baseline and group A1). These changes were mainly attributed to atorvastatin treatment. Among the CKD stage 3 patients there were no CVD events in group A1, while 6 events occurred in group B1 (p = 0.014).

CONCLUSIONS

Multifactorial intervention in patients with MetS without established CVD improved renal function and reduced SUA levels. These changes were more prominent in stage 3 CKD patients and might have contributed to the reduction in eCVD risk and clinical events. Original study registration number [ClinicalTrials.gov ID: NCT00416741].

Recent advances in the treatment of atherogenic dyslipidemia in type 2 diabetes mellitus

Despite best treatment efforts reducing low-density lipoprotein cholesterol, a substantial number of type 2 diabetes mellitus patients still experience progression of cardiovascular risk. Even with intensification of statin therapy, a substantial residual cardiovascular risk remains and atherogenic dyslipidemia is an important driver of this so-called residual risk. Besides statin therapy, new strategies evaluate the role of intensive combination lipid treatment for the entire type 2 diabetic population. The results from the ACCORD (Action to Control Cardiovascular Risk in Diabetes) Lipid trial suggest that there is a lipid-related modifiable component to cardiovascular residual risk in statin-treated type 2 diabetic patients, and that further research should address patients with triglycerides above 204 mg/dl and high-density lipoprotein cholesterol below 34 mg/dl. Based on their respective lipid-modifying activity, the combination of a fibrate and statin is a logical approach to improving achievement of lipid targets in statin-treated patients with a glomerular filtration rate of >60 ml/min/1.73 m(2) and with residual atherogenic dyslipidemia. The link between dyslipidemia treatment and diabetic retinopathy, nephropathy and neuropathy is an emerging new field and microvascular complications are targets for new treatments.

Basics of systematic reviews and meta-analyses for the nephrologist

Renal practitioners are expected to apply the best available evidence from rigorous scientific research to clinical decision-making and also for policy-making for those involved. Advances in information technology and unprecedented access to data have simplified the process for the search of best available evidence to guide practice. However, it is challenging to cope with the increasing volume of publications in nephrology and other areas of medicine. Accordingly, systematic reviews and meta-analysis have greatly facilitated best practice and effective clinical decision-making. Conducting a systematic review/meta-analysis involves a number of steps that start with protocol development and research question formulation, design and study selection criteria, followed by retrieval of potentially relevant studies, selection of those studies to be included and evaluation of a study's risk of bias. Systematic reviews and meta-analyses have both strengths and weaknesses. Many of the perceived limitations of meta-analysis are not inherent in the methodology, but actually represent deficits in the conduct or reporting of individual primary studies. With the continuous proliferation of published renal clinical studies, such publications will continue to be an important resource for clinicians and researchers in nephrology. It is therefore important for nephrologists to keep abreast of developments in this field, which requires some knowledge about how these studies are conducted, reported and how to appraise them for application to clinical practice or policy-making.