Trends in incidence of treated end-stage renal disease, overall and by primary renal disease, in persons aged 20?64�years in Europe, Canada and the Asia-Pacific region, 1998?2002

Magnetic resonance imaging based kidney volume assessment for risk stratification in pediatric autosomal dominant polycystic kidney disease

Introduction

In the pediatric context, most children with autosomal dominant polycystic kidney disease (ADPKD) maintain a normal glomerular filtration rate (GFR) despite underlying structural kidney damage, highlighting the critical need for early intervention and predictive markers. Due to the inverse relationship between kidney volume and kidney function, risk assessments have been presented on the basis of kidney volume. The aim of this study was to use magnetic resonance imaging (MRI)-based kidney volume assessment for risk stratification in pediatric ADPKD and to investigate clinical and genetic differences among risk groups.

Methods

This multicenter, cross-sectional, and case-control study included 75 genetically confirmed pediatric ADPKD patients (5-18 years) and 27 controls. Kidney function was assessed by eGFR calculated from serum creatinine and cystatin C using the CKiD-U25 equation. Blood pressure was assessed by both office and 24-hour ambulatory measurements. Kidney volume was calculated from MRI using the stereological method. Total kidney volume was adjusted for the height (htTKV). Patients were stratified from A to E classes according to the Leuven Imaging Classification (LIC) using MRI-derived htTKV.

Results

Median (Q1-Q3) age of the patients was 6.0 (2.0-10.0) years, 56% were male. There were no differences in sex, age, height-SDS, or GFR between the patient and control groups. Of the patients, 89% had PKD1 and 11% had PKD2 mutations. Non-missense mutations were 73% in PKD1 and 75% in PKD2. Twenty patients (27%) had hypertension based on ABPM. Median htTKV of the patients was significantly higher than controls (141 vs. 117 ml/m, p = 0.0003). LIC stratification revealed Classes A (38.7%), B (28%), C (24%), and D + E (9.3%). All children in class D + E and 94% in class C had PKD1 variants. Class D + E patients had significantly higher blood pressure values and hypertension compared to other classes (p > 0.05 for all).

Discussion

This study distinguishes itself by using MRI-based measurements of kidney volume to stratify pediatric ADPKD patients into specific risk groups. It is important to note that PKD1 mutation and elevated blood pressure were higher in the high-risk groups stratified by age and kidney volume. Our results need to be confirmed in further studies.

Predicting autosomal dominant polycystic kidney disease progression: review of promising Serum and urine biomarkers

Autosomal dominant polycystic kidney disease (ADPKD) is one of the leading causes of end-stage renal disease. In spite of the recent tremendous progress in the understanding of ADPKD pathogenesis, the molecular mechanisms of the disease remain incompletely understood. Considering emerging new targeted therapies for ADPKD, it has become crucial to disclose easily measurable and widely available biomarkers for identifying patients with future rapid disease progression. This review encompasses all the research with a shared goal of identifying promising serum or urine biomarkers for predicting ADPKD progression or response to therapy. The rate of the ADPKD progress varies significantly between patients. The phenotypic variability is only partly explained by the underlying genetic lesion diversity. Considering significant decline in kidney function in ADPKD is not usually evident until at least 50% of the parenchyma has been destroyed, conventional kidney function measures, such as glomerular filtration rate (GFR), are not suitable for monitoring disease progression in ADPKD, particularly in its early stages. Since polycystic kidney enlargement usually precedes the decline in GFR, height-adjusted total kidney volume (ht-TKV) has been accepted as an early biomarker for assessing disease severity in ADPKD patients. However, since measuring ht-TKV is time-consuming and observer-dependent, the identification of a sensitive and quickly measurable biomarker is of a great interest for everyday clinical practice. Throughout the last decade, due to development of proteomic and metabolomic techniques and the enlightenment of multiple molecular pathways involved in the ADPKD pathogenesis, a number of urine and serum protein biomarkers have been investigated in ADPKD patients, some of which seem worth of further exploring. These include copeptin, angiotensinogen, monocyte chemoattractant protein 1, kidney injury molecule-1 and urine-to-plasma urea ratio among many others. The aim of the current review is to provide an overview of all of the published evidence on potentially clinically valuable serum and urine biomarkers that could be used for predicting disease progression or response to therapy in patients with ADPKD. Hopefully, this review will encourage future longitudinal prospective clinical studies evaluating proposed biomarkers as prognostic tools to improve management and outcome of ADPKD patients in everyday clinical practice.

Impending challenges of the burden of end-stage kidney disease in Australia

Sex and age-specific incidence rates of patients with treated end-stage kidney disease (ESKD) in Australia are comparable to those in European countries, but substantially lower compared with those in the United States, Canada and many Asian countries. The incidence rates of treated ESKD in Australia increase with advancing age; however, the incidence of ESKD is likely to be underestimated because a proportion of patients with ESKD (about 50%) remain untreated. Late referral to nephrologists has reduced over the past decade, temporally associated with improved ESKD recognition. However, late referral still occurs in one in five Australians with ESKD. One in two Australians with ESKD has diabetes, with up to 35% of cases directly attributed to diabetes. Mortality rates for patients with ESKD remain substantially higher compared with the age-matched general population, although there has been a significant improvement in survival over time. Cardiovascular disease and cancer are the two most common causes of death in patients with ESKD.

Pyrroloquinoline quinine protects HK-2 cells against high glucose-induced oxidative stress and apoptosis through Sirt3 and PI3K/Akt/FoxO3a signaling pathway

High glucose(HG)-induced oxidative stress and apoptosis in renal tubular epithelial cells play an important role in the pathogenesis of diabetic nephropathy. Pyrroloquinoline quinine (PQQ), a new B vitamin, has been demonstrated to be important in antioxidant and anti-apoptotic effects. However, its effect on HK-2 cells and the potential mechanism are rarely investigated. In this study, we investigated that PPQ had protective effects against HG-induced oxidative stress damage and apoptosis in vitro model of diabetic nephropathy. PPQ at 10, 100, 500, 1000 and 10000 nM could protect HK-2 cell from HG-induced inhibition. The protective effects of PQQ were associated with increasing the level of antioxidants(SOD2, CAT), inhibition of reactive oxygen species(ROS) production, and dependent modulation of Bcl-2 family proteins. PPQ significantly upregulated the protein and mRNA expression of Sirtuin3(Sirt3) in HG-induced HK-2 cells. PPQ also reduced apoptosis in HG-induced HK-2 cells by the PI3K/Akt/FoxO3a signal pathway. As down-regulated sirt3 or inhibitory the activity of PI3K/Akt/FoxO3a pathway, the protective effects of PPQ were weakened. In conclusion, our data suggest that PPQ achieves the protective effects through PI3K/Akt/FoxO3a pathway and dependent modulation of Sirt3.

Effect of valsartan on kidney outcomes in people with impaired glucose tolerance

AIMS

To examine the effect of valsartan on kidney outcomes in patients with impaired glucose tolerance (IGT).

METHODS

In a double-blind randomized trial, 9306 patients with IGT were assigned to valsartan (160 mg daily) or placebo. The co-primary endpoints were the development of diabetes and two composite cardiovascular outcomes. Prespecified renal endpoints included: the composite of renal death, end-stage renal disease (ESRD) or doubling of serum creatinine; estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m² ; hospitalization for renal failure; and progression from normoalbuminuria to microalbuminuria, microalbuminuria to macroalbuminuria, and normoalbuminuria to macroalbuminuria. The median follow-up was 6.2 years.

RESULTS

Valsartan reduced the incidence of diabetes but not cardiovascular events. In the valsartan group, 25/4631 patients (0.5%), vs 26/4675 (0.6%) patients in the placebo group, developed ESRD or experienced doubling of serum creatinine (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.55-1.66; P  = .87). Few patients in either group developed an eGFR of ≤30 mL/min/1.73 m² or had a renal hospitalization. Fewer patients on valsartan (237/4084 [5.8%]) than on placebo (342/4092 [8.4%]) developed microalbuminuria (HR 0.68, 95% CI 0.57-0.80; P  < .0001), and fewer valsartan-treated patients developed macroalbuminuria. Overall, urinary albumin-to-creatinine ratio (UACR) was 11% lower with valsartan (95% CI 8-13; P  < .0001) and 9% lower (95% CI 6-11; P  < .0001) after adjusting for both glucose and blood pressure.

CONCLUSIONS

The effect of valsartan on UACR was not wholly explained by change in blood pressure or glucose. Valsartan reduced the incidence of microalbuminuria in IGT without increasing the incidence of hyperkalaemia or renal dysfunction compared with placebo.

Urinary Proteomics for Diagnosis and Monitoring of Diabetic Nephropathy

The last decade has seen a surge in publications describing novel biomarkers for early detection of diabetic nephropathy (DN), but as yet none have outperformed albuminuria in well-designed prospective studies. This is partially attributable to our incomplete understanding of the many complex interrelated mechanisms underlying DN development, a heterogeneous process unlikely to be captured by a single biomarker. Proteomics offers the advantage of simultaneously analysing the entire protein content of a biological sample, and the technique has gained attention as a potential tool for a more accurate diagnosis of disease at an earlier stage as well as a means by which to unravel the pathogenesis of complex diseases such as DN using an untargeted approach. This review will discuss the potential of proteomics as both a clinical and research tool, evaluating exploratory work in animal models as well as diagnostic potential in human subjects.

Update on Mechanisms of Renal Tubule Injury Caused by Advanced Glycation End Products

Diabetic nephropathy (DN) caused by advanced glycation end products (AGEs) may be associated with lipid accumulation in the kidneys. This study was designed to investigate whether Nε-(carboxymethyl) lysine (CML, a member of the AGEs family) increases lipid accumulation in a human renal tubular epithelial cell line (HK-2) via increasing cholesterol synthesis and uptake and reducing cholesterol efflux through endoplasmic reticulum stress (ERS). Our results showed that CML disrupts cholesterol metabolism in HK-2 cells by activating sterol regulatory element-binding protein 2 (SREBP-2) and liver X receptor (LXR), followed by an increase in 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR) mediated cholesterol synthesis and low density lipoprotein receptor (LDLr) mediated cholesterol uptake and a reduction in ATP-binding cassette transporter A1 (ABCA1) mediated cholesterol efflux, ultimately causing lipid accumulation in HK-2 cells. All of these responses could be suppressed by an ERS inhibitor, which suggests that CML causes lipid accumulation in renal tubule cells through ERS and that the inhibition of ERS is a potential novel approach to treating CML-induced renal tubular foam cell formation.

The Incidence of End-Stage Renal Disease in the Diabetic (Compared to the Non-Diabetic) Population: A Systematic Review

End-stage renal disease (ESRD) in diabetes is a life threatening complication resulting in a poor prognosis for patients as well as high medical costs. The aims of this systematic review were (1) to evaluate the incidence of ESRD due to all causes and due to diabetic nephropathy in the diabetic population and differences between incidences of ESRD with respect to sex, ethnicity, age and regions, (2) to compare incidence rates in the diabetic and non-diabetic population, and (3) to investigate time trends. The systematic review was conducted according to the PRISMA group guidelines by performing systematic literature searches in the biomedical databases until January 3rd 2015; thirty-two studies were included. Among patients with incident type 1 diabetes the 30-year cumulative incidence ranged from 3.3% to 7.8%. Among patients with prevalent diabetes, incidence rates of ESRD due to all causes ranged from 132.0 to 167.0 per 100,000 person-years, whereas incidence rates of ESRD due to diabetic nephropathy varied from 38.4 to 804.0 per 100,000 person-years. The incidence of ESRD in the diabetic population was higher compared to the non-diabetic population, and relative risks varied from 6.2 in the white population to 62.0 among Native Americans. The results regarding time trends were inconsistent. The review conducted demonstrates the considerable variation of incidences of ESRD among the diabetic population. Consistent findings included an excess risk when comparing the diabetic to the non-diabetic population and ethnic differences. We recommend that newly designed studies should use standardized methods for the determination of ESRD and population at risk.

A before and after cross-sectional analysis of a public health campaign to increase kidney health awareness in a Canadian province

BACKGROUND

Chronic kidney disease (CKD) has a major impact on patient health and health system resources. The prevalence of kidney disease is increasing, with Manitoba being one of the provinces in Canada with the highest per capita rate of CKD and end stage renal disease (Anonymous, Canadian organ replacement register annual report: treatment of end-stage organ failure in Canada, 2001-2010, 2011). In 2011, a public health campaign to promote kidney health, by increasing awareness of CKD and its risk factors, was created to target high-risk individuals such as First Nations and those with hypertension and diabetes in urban and rural/remote Manitoba. In this study, we aimed to determine the effectiveness of this public health campaign on increasing the awareness of CKD.

METHODS

Our public health campaign ran in March 2011, and employed a multifaceted approach with radio, television, internet, and print advertisements. Campaign awareness and understanding of the public health message were assessed with a telephone omnibus survey of randomly selected individuals with a Manitoba area code during February and April 2011. A before and after cross-sectional analysis was utilized to measure the effect of exposure to the campaign in telephone respondents.

RESULTS

1606 individuals participated in the survey (804 pre and 802 post). Overall awareness of the campaign messaging increased from 7% pre campaign to 25% in the post campaign period. Approximately two-thirds of respondents correctly identified a main theme message of the campaign. Awareness improved across most subgroups surveyed aside from those with lower education and income.

CONCLUSIONS

Our study demonstrates the effective reach of our campaign and its relative effectiveness at raising awareness of chronic kidney disease and its risk factors.

International burden of chronic kidney disease and secondary hyperparathyroidism: a systematic review of the literature and available data

The international burden of secondary hyperparathyroidism (SHPT) is unknown, but it may be estimable through the available chronic kidney disease and SHPT literature. Structured reviews of biomedical literature and online data systems were performed for selected countries to ascertain recent estimates of the incidence, prevalence, and survival of individuals with CKD and SHPT. International societies of nephrology were contacted to seek additional information regarding available data. Estimates were abstracted from 35 sources reporting estimates of CKD in 25 countries. Population prevalence estimates of CKD stages 3-5 in adults ranged from approximately 1 to 9% (China, Mexico, resp.). Estimates of the population prevalence of maintenance dialysis therapy ranged from 79 per million population (pmp; China) to 2385 pmp (Japan); incidence rates ranged from 91 pmp (United Kingdom) to 349 pmp (United States). Prevalence of SHPT among stage 5D populations was highly variable and dependent upon the disease definition used. Among the few nations reporting, approximately 30-50% of stage 5D patients had serum parathyroid hormone levels >300 pg/mL. Reported incidence and prevalence estimates across the individual nations were variable, likely reflecting differing population demographics, risk factors, etiologies, and availability of treatment through all stages of CKD.

Azilsartan improves glycemic status and reduces kidney damage in zucker diabetic fatty rats

BACKGROUND

Azilsartan medoxomil (AZL-M), an angiotensin II receptor blocker, demonstrates antihypertensive and organ protective effects in hypertension. We investigated the efficacy of AZL-M to ameliorate metabolic syndrome and kidney damage associated with type 2 diabetes using Zucker diabetic fatty (ZDF) rats.

METHODS

ZDF rats were treated with vehicle or AZL-M for 8 weeks. Zucker diabetic lean (ZDL) rats were used as controls. Urine and plasma samples were collected for biochemical analysis, and kidney tissues were used for histopathological and immunohistopathological examination at the end of the 8-week protocol.

RESULTS

ZDF rats were diabetic with hyperglycemia and impaired glucose tolerance, and AZL-M ameliorated the diabetic phenotype. ZDF rats were hypertensive compared with ZDL rats (181±6 vs. 129±7mm Hg), and AZL-M decreased blood pressure in ZDF rats (116±7mm Hg). In ZDF rats, there was marked renal damage with elevated proteinuria, albuminuria, nephrinuria, 2-4-fold higher tubular cast formation, and glomerular injury compared with ZDL rats. AZL-M treatment reduced renal damage in ZDF rats. ZDF rats demonstrated renal inflammation and oxidative stress with elevated urinary monocyte chemoattractant protein 1 excretion, renal infiltration of macrophages, and elevated kidney malondialdehyde levels. AZL-M reduced oxidative stress and inflammation in ZDF rats.

CONCLUSIONS

Overall, we demonstrate that AZL-M attenuates kidney damage in type 2 diabetes. We further demonstrate that anti-inflammatory and antioxidative activities of AZL-M contribute to its kidney protective action.

Proteomics and diabetic nephropathy: what have we learned from a decade of clinical proteomics studies?

Diabetic nephropathy (DN) has become the most frequent cause of chronic kidney disease worldwide due to the constant increase of the incidence of type 2 diabetes mellitus in developed and developing countries. The understanding of the pathophysiological mechanisms of human diseases through a large-scale characterization of the protein content of a biological sample is the key feature of the proteomics approach to the study of human disease. We discuss the main results of over 10 years of tissue and urine proteomics studies applied to DN in order to understand how far we have come and how far we still have to go before obtaining a full comprehension of the molecular mechanisms involved in the pathogenesis of DN and identifying reliable biomarkers for accurate management of patients.

Proteinuria, (99m) Tc-DTPA Scintigraphy, Creatinine-, Cystatin- and Combined-Based Equations in the Assessment of Chronic Kidney Disease

Background. Precise estimation of the glomerular filtration rate (GFR) and the identification of markers of progression are important. We compared creatinine, cystatin, and combined CKD-EPI equations with ^99mTc-DTPA scintigraphy to measure GFR and proteinuria as markers of progression. Methods. Cross-sectional, observational study including 300 subjects. CKD was classified by ^99mTc-DTPA scintigraphy. Determinations. Creatinine, 24-hour creatinine clearance, cystatin, Hoek formula, and creatinine, cystatin, and combined CKD-EPI equations. Results. In the global assessment, creatinine CKD-EPI and combined CKD-EPI equations yielded the highest correlations with ^99mTc-DTPA: ρ = 0.839, P < 0.0001 and ρ = 0.831, P < 0.0001. Intergroup analysis versus ^99mTc-DTPA: control G, creatinine clearance ρ = 0.414, P = 0.013; G3, combined CKD-EPI ρ = 0.5317, P < 0.0001; G4, Hoek ρ = 0.618, P < 0.0001, combined CKD-EPI ρ = 0.4638, P < 0.0001; and G5, creatinine clearance ρ = 0.5414, P < 0.0001, combined CKD-EPI ρ = 0.5288, P < 0.0001. In the global assessment, proteinuria displayed the highest significant correlations with cystatin (ρ = 0.5433, P < 0.0001) and cystatin-based equations (Hoek: ρ = −0.5309, P < 0.0001). When GFR < 60 mL/min: in stage 3, proteinuria-cystatin (ρ = 0.4341, P < 0.0001); proteinuria-Hoek (ρ = −0.4105, P < 0.0001); in stage 4, proteinuria-cystatin (ρ = 0.4877, P < 0.0001); proteinuria-Hoek (ρ = −0.4877, P = 0.0026). Conclusions. At every stage of GFR < 60 mL/min, cystatin-based equations displayed better correlations with ^99mTc-DTPA. Proteinuria and cystatin-based equations showed strong associations and high degrees of correlation.

Parameters of glycemic control in type 2 diabetic patients on hemodialysis or peritoneal dialysis: implications for clinical practice

OBJECTIVE

To better explore the relationship between parameters of glycemic control of T2DM in RRT, we studied 23 patients on hemodialysis (HD), 22 on peritoneal dialysis (PD), and compared them with 24 T2DM patients with normal renal function (NRF).

MATERIALS AND METHODS

We performed, on four consecutive days, 10 assessments of capillary blood glucose [4 fasting, 2 pre- and 4 postprandial (post-G) and average (AG)], random glycemia, and HbA1c in all patients.

RESULTS

Preprandial blood glucose was greater in patients on RRT compared with NRF. Correlations between AG and HbA1c were 0.76 for HD, 0.66 for PD, and 0.82 for NRF. The regression lines between AG and HbA1c were similar for patients on HD and with NFR, but they were displaced upward for PD.

CONCLUSION

Similar HbA1c values in PD patients may correspond to greater levels of AG than in HD or NRF patients.

Incidence of end-stage renal disease in the Turkish-Cypriot population of Northern Cyprus: a population based study

BACKGROUND

This is the first report of the incidence and causes of end-stage renal disease (ESRD) of the Turkish-Cypriot population in Northern Cyprus.

METHODS

Data were collected over eight consecutive years (2004-2011) from all those starting renal replacement therapy (RRT) in this population. Crude and age-standardised incidence at 90 days was calculated and comparisons made with other national registries. We collected DNA from the entire prevalent population. As an initial experiment we looked for two genetic causes of ESRD that have been reported in Greek Cypriots.

RESULTS

Crude and age-standardised incidence at 90 days was 234 and 327 per million population (pmp) per year, respectively. The mean age was 63, and 62% were male. The age-adjusted prevalence of RRT in Turkish-Cypriots was 1543 pmp on 01/01/2011. The incidence of RRT is higher than other countries reporting to the European Renal Association - European Dialysis and Transplant Association, with the exception of Turkey. Diabetes is a major cause of ESRD in those under 65, accounting for 36% of incident cases followed by 30% with uncertain aetiology. 18% of the incident population had a family history of ESRD. We identified two families with thin basement membrane nephropathy caused by a mutation in COL4A3, but no new cases of CFHR5 nephropathy.

CONCLUSIONS

This study provides the first estimate of RRT incidence in the Turkish-Cypriot population, describes the contribution of different underlying diagnoses to ESRD, and provides a basis for healthcare policy planning.

Renoprotective effects of berberine and its possible molecular mechanisms in combination of high-fat diet and low-dose streptozotocin-induced diabetic rats

Berberine (BBR), an effective compound of Chinese traditional herbal medicine, has preventive effects on diabetes and its complications. In this study, we investigated the therapeutic effects and underlying molecular mechanisms of BBR in rats with high-fat diet and streptozotocin (STZ)-induced diabetic nephropathy model. BBR (50, 100, 200 mg/kg/d) were orally administered to male Sprague-Dawley rats after STZ injection and conducted for 8 weeks. Renal damage was evaluated by kidney weight to body weight ratio (KW/BW), urine microalbumin (UMAlb), urine protein for 24 h (UP24 h), urine creatinine (UCr), and histological examination. Type IV collagen and transforming growth factor-beta1 (TGF-β1) were detected by immunohistochemistry and ultrastructure of glomeruli was observed. Fasting blood glucose (FBG),serum creatinine (SCr), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c) in serum and G protein-coupled receptor kinases (GRKs), cAMP in kidney were measured. Remarkable renal damage, hyperglycemia and hyperlipidemia were observed in DN rats. BBR could restore renal functional parameters, suppress alterations in histological and ultrastructural changes in the kidney tissues, improve glucose and lipid metabolism disorders, and increase cAMP levels compared with those of DN model group. Furthermore, BBR down-regulated total protein expression of GRK2, GRK3 and up-regulated expression of GRK6 of renal cortex in DN rats, but had a slight effects on GRK4 and GRK5. These studies demonstrate, for the first time, that BBR exerts renoprotection in high-fat diet and STZ-induced DN rats by modulating the proteins expression of GRKs in G protein- AC-cAMP signaling pathway.

Treatment outcomes for ischemic heart disease in dialysis-dependent patients

Objective: To compare outcomes following intervention in dialysis-dependent patients with ischemic heart disease.

Background: Ischemic heart disease is a major cause of mortality in dialysis-dependent patients. Coronary revascularization and medical modification to relieve symptoms is common, however, there is no clear consensus regarding optimal treatment.

Method: Ninety dialysis-dependent patients with ischemic heart disease were prospectively assessed between 1999 and 2009, with a median follow-up of 24 months; 35 received best medical management, 31 had percutaneous coronary angioplasty and stenting, and 24 had coronary artery bypass grafting.

Results: By multivariate analysis, higher body mass index and lower logistic EuroSCORE were associated with having either procedure compared to medical management. Using the time-to-event Kaplan-Meier method, both stenting and coronary bypass grafting had lower risks of an adverse outcome than best medical management. Mortality was 40/90 (44.4%). Multivariate predictors of mortality were smoking and a logistic EuroSCORE of 7–14. Overall mortality was not different among groups, however, the stent group had a survival advantage at 30-days and 1-year compared to the coronary bypass group. Composite median survival was 52.3 months. SF-36 questionnaires showed quality of life after bypass grafting was significantly better than medical management or stenting. Physical function was better after bypass grafting compared to medical management or stenting.

Conclusion: Dialysis-dependent patients with ischemic heart disease have poor survival despite intervention. Coronary artery bypass achieves fewer composite adverse events and better quality of life than stenting. Symptoms and coronary anatomy should dictate treatment decisions in dialysis-dependent patients.

Diabetic nephropathy amelioration by a low-dose sitagliptin in an animal model of type 2 diabetes (Zucker diabetic fatty rat)

This study was performed to assess the effect of chronic low-dose sitagliptin, a dipeptidyl peptidase 4 inhibitor, on metabolic profile and on renal lesions aggravation in a rat model of type-2 diabetic nephropathy, the Zucker diabetic fatty (ZDF) rat. Diabetic and obese ZDF (fa/fa) rats and their controls ZDF (+/+) were treated for 6 weeks with vehicle (control) or sitagliptin (10 mg/kg/bw). Blood/serum glucose, HbA1c, insulin, Total-c, TGs, urea, and creatinine were assessed, as well as kidney glomerular and tubulointerstitial lesions (interstitial fibrosis/tubular atrophy), using a semiquantitative rating from 0 (absent/normal) to 3 (severe and extensive damage). Vascular lesions were scored from 0-2. Sitagliptin in the diabetic rats promoted an amelioration of glycemia, HbA1c, Total-c, and TGs, accompanied by a partial prevention of insulinopenia. Furthermore, together with urea increment prevention, renal lesions were ameliorated in the diabetic rats, including glomerular, tubulointerstitial, and vascular lesions, accompanied by reduced lipid peroxidation. In conclusion, chronic low-dose sitagliptin treatment was able to ameliorate diabetic nephropathy, which might represent a key step forward in the management of T2DM and this serious complication.

Critical role of chemokine (C-C motif) receptor 2 (CCR2) in the KKAy + Apoe -/- mouse model of the metabolic syndrome

AIMS/HYPOTHESIS

Chemokines and their receptors such as chemokine (C-C motif) receptor 2 (CCR2) may contribute to the pathogenesis of the metabolic syndrome via their effects on inflammatory monocytes. Increased accumulation of CCR2-driven inflammatory monocytes in epididymal fat pads is thought to favour the development of insulin resistance. Ultimately, the resulting hyperglycaemia and dyslipidaemia contribute to development of the metabolic syndrome complications such as cardiovascular disease and diabetic nephropathy. Our goal was to elucidate the role of CCR2 and inflammatory monocytes in a mouse model that resembles the human metabolic syndrome.

METHODS

We generated a model of the metabolic syndrome by backcrossing KKAy ( + ) with Apoe ( -/- ) mice (KKAy ( + ) Apoe ( -/- )) and studied the role of CCR2 in this model system.

RESULTS

KKAy ( + ) Apoe ( -/- ) mice were characterised by the presence of obesity, insulin resistance, dyslipidaemia and increased systemic inflammation. This model also manifested two complications of the metabolic syndrome: atherosclerosis and diabetic nephropathy. Inactivation of Ccr2 in KKAy (+) Apoe ( -/- ) mice protected against the metabolic syndrome, as well as atherosclerosis and diabetic nephropathy. This protective phenotype was associated with a reduced number of inflammatory monocytes in the liver and muscle, but not in the epididymal fat pads; circulating levels of adipokines such as leptin, resistin and adiponectin were also not reduced. Interestingly, the proportion of inflammatory monocytes in the liver, pancreas and muscle, but not in the epididymal fat pads, correlated significantly with peripheral glucose levels.

CONCLUSIONS/INTERPRETATION

CCR2-driven inflammatory monocyte accumulation in the liver and muscle may be a critical pathogenic factor in the development of the metabolic syndrome.

Trends in renal replacement therapy in Turkey, 1996-2008

BACKGROUND

National renal registry studies providing data for incidence, prevalence, and characteristics of end-stage renal disease and renal replacement therapy (RRT) serve as a basis to determine national strategies for the prevention and treatment of these diseases and identify new areas for special studies.

STUDY DESIGN

Since 1990, the Turkish Society of Nephrology has been coordinating a national renal registry that collects data on patients receiving RRT. This report focuses on data collected from 1996-2008.

SETTING & PARTICIPANTS

Data were collected in dialysis centers for patients on RRT.

PREDICTOR

Year.

OUTCOMES

Point prevalence and incidence of RRT, RRT modalities, demographic and clinical characteristics of patients on RRT.

RESULTS

From 1996 to 2008, the number of centers (199 and 760) and response rates to the registry (76% and 99.4%) increased. In 2008, the point prevalence of RRT was 756 per million population (pmp) and incidence was 188 pmp, including pediatric patients. In prevalent patients, the most common RRT modality was hemodialysis (77.0% of patients), followed by peritoneal dialysis (10.1%) and transplant (12.9%). The age of hemodialysis and transplant patients increased, with a predominance of male patients. Percentages of diabetes mellitus and hypertension as causes of ESRD increased, whereas those of chronic glomerulonephritis and urologic disease decreased. Infection and crude death rates decreased in all treatment modalities.

LIMITATIONS

The main study limitations were registry design and low number of kidney transplants.

CONCLUSION

With increasing numbers of dialysis centers and RRT patients during the last 12 years, the need for RRT in Turkey has been better met. The quality of RRT care has improved, especially regarding prevention and treatment of infections.

Syndrome of rapid-onset end-stage renal disease: a new unrecognized pattern of CKD progression to ESRD

By most estimates, we have an increasing worldwide end-stage renal disease (ESRD) epidemic. This is despite at least two decades of intensified reno-protection strategies, including attempts at optimal hypertension management, optimization of diabetic control, smoking cessation efforts, and the extensive application of renin-angiotensin-aldosterone system (RAAS) blockade in both diabetic and nondiabetic chronic nephropathies. The current consensus is that chronic kidney disease (CKD) progression to ESRD is a continuous, progressive, and predictable loss of estimated glomerular filtration rate (eGFR) in CKD patients, inexorably leading to ESRD. Our recent experience in a Mayo Health System Hypertension Clinic, as well as new reports associating ESRD development in CKD patients with episodes of acute kidney injury (AKI), led us to hypothesize that CKD to ESRD progression may not be that predictable, after all. Among a 100 high-risk CKD patient cohort that we have followed up prospectively since 2002, we demonstrated that in 15 of 17 (88%) patients who progressed to ESRD, progression from CKD to ESRD was unpredictable, nonlinear, abrupt, and rapid, and this followed AKI secondary to medical and surgical events. We have coined a new term, the syndrome of rapid-onset end-stage renal disease (SORO-ESRD), to represent this unrecognized syndrome. Larger studies are warranted to confirm our single-center findings. If confirmed to represent a significant proportion of the ESRD population, at least here in the United States, this finding will demand major paradigm shifts in the current concepts of reno-protection and "A-V Fistula first" programs.

Attributes of antiangiogenic factor plasminogen kringle 5 in glomerulonephritis

CONTEXT

Plasminogen kringle domain (K) 5 is known to inhibit endothelial cell growth, but limited data are available investigating the relationship between K5 and glomerulonephritis (GN).

OBJECTIVE

To understand the relationships among K5, GN, and glomerular endothelial cells in GN mice models and human subjects.

DESIGN

Two mice models of GN and 2 categories of human GN biopsy samples were collected to gain insight into the disease mechanism from the laboratory to bedside. In the mechanistic animal study, membranous nephropathy (MN) and focal segmental glomerulosclerosis mice models were used. Kringle domain 5 in the diseased kidney was located by immunofluorescence and quantified by Western blotting. In the kinetic animal study, different MN time points were stained with K5, immunoglobulin G, and C3 by immunofluorescence. CD31 and proliferating cell nuclear antigen were evaluated by immunohistochemical double staining for alterations in the glomerular endothelial cells. Biopsy samples from patients diagnosed with antibody (Ab)-mediated and non-Ab-mediated GN were collected for K5 analysis.

RESULTS

The expression level of K5 was found to be significant in MN, but not in focal segmental glomerulosclerosis, and was markedly elevated in the diseased glomeruli along the capillary walls. Kringle domain 5 levels increased steadily with the evolution of MN, appearing after the deposition of Abs. In altered glomerular endothelial cells, CD31 decreased with the evolution of MN. In human subjects, K5 occurred only in patients with Ab GN.

CONCLUSIONS

Kringle domain 5 might be involved in the progression of Ab-mediated GN and associated with the alteration of MN glomerular endothelial cell growth.

The value of IgG-uria in predicting renal failure in idiopathic glomerular diseases. A long-term follow-up study

BACKGROUND

Proteinuria is the hallmark of glomerular disease and non-selective proteinuria is often associated with progression to renal failure. The predictive value of urine IgG excretion was studied comprehensively in patients with nephrotic syndrome. In the present follow-up study, we examine the predictive value of IgG-uria in patients with idiopathic glomerular diseases with a wide range of proteinuia.

METHODS

A total of 189 (113 males and 76 females) patients with idiopathic glomerulonephritis and serum creatinine of less than 150 μmol/L diagnosed between 1993 and 2004 were followed up to their last visit in 2009. Measurement of urine excretion of albumin, IgG, and protein HC were performed in the early morning of spot urine samples collected at the time of the diagnostic renal biopsy. Patients were stratified according to urine protein concentrations and the progression rate to end-stage renal disease (ESRD) calculated using Kaplan-Meier survival analysis. ESRD was defined as the start of renal replacement therapy.

RESULTS

During the study follow-up time of 1429 person-years; 26 (13.8%) patients reached ESRD. The overall mean kidney survival time of studied patients with serum creatinine less than 150 were 13.4 years. The incidence rate of ESRD was ∼18 per 1000 person-years. Stratified analysis identified urinary excretion of IgG, but not albuminuria, as predictor of ESRD. The progression rate to ESRD was 36 per 1000 person-years in patients with urine IgG concentration exceeding 5 mg/mmol urine creatinine, compared to a progression rate of 6/1000 person-years for patients with lower levels of urine IgG.

CONCLUSION

The findings of the study suggest that at early stages, the level of IgG-uria is useful to be used in risk stratification of patients with proteinuric glomerular diseases.

The global burden of diabetes and its complications: an emerging pandemic

The number of patients with type 2 diabetes is increasing rapidly in both developed and developing countries around the world. The emerging pandemic is driven by the combined effects of population ageing, rising levels of obesity and inactivity, and greater longevity among patients with diabetes that is attributable to improved management. The vascular complications of type 2 diabetes account for the majority of the social and economic burden among patients and society more broadly. This review summarizes the burden of type 2 diabetes, impaired glucose tolerance, and their vascular complications. It is projected that by 2025 there will be 380 million people with type 2 diabetes and 418 million people with impaired glucose tolerance. Diabetes is a major global cause of premature mortality that is widely underestimated, because only a minority of persons with diabetes dies from a cause uniquely related to the condition. Approximately one half of patients with type 2 diabetes die prematurely of a cardiovascular cause and approximately 10% die of renal failure. Global excess mortality attributable to diabetes in adults was estimated to be 3.8 million deaths.

Diabetic angiopathy, the complement system and the tumor necrosis factor superfamily

Among the most serious consequences of diabetes mellitus is the development of diabetic angiopathy, of which the clinical features are cardiovascular disease, retinopathy, nephropathy and neuropathy. Diabetic kidney problems affect up to one third of all patients with diabetes mellitus and are a major cause of end-stage renal failure. Although a huge number of pharmaceutical interventions are available today, diabetic angiopathy remains a leading cause of mortality and morbidity in diabetes mellitus, therefore, an urgent need exists to develop new therapeutic strategies. Recent data support the hypothesis that dysregulation of the complement system and of members of the tumor necrosis factor (TNF) superfamily may be involved in the development of diabetic vascular complications. The mannose-binding lectin pathway-an overall regulatory component of the complement system-is a particularly promising biomarker as it is directly involved in the development of diabetic angiopathy. In addition, two components of the TNF superfamily, namely TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) and osteoprotegerin, may be involved in the pathogenesis of diabetic angiopathy. Several ways of specifically manipulating the complement and TNF superfamily systems already exist, but whether or not these drugs provide new targets for intervention for late diabetic complications is still to be revealed.

Human glomerular endothelium: interplay among glucose, free fatty acids, angiotensin II, and oxidative stress

Glomerular endothelial cells (GEC) are strategically situated within the capillary loop and adjacent to the glomerular mesangium. GEC serve as targets of metabolic, biochemical, and hemodynamic signals that regulate the glomerular microcirculation. Unequivocally, hyperglycemia, hypertension, and the local renin-angiotensin system partake in the initiation and progression of diabetic nephropathy (DN). Whether free fatty acids (FFA) and reactive oxygen species (ROS) that have been associated with the endothelial dysfunction of diabetic macrovascular disease also contribute to DN is not known. Since endothelial cells from different organs and from different species may display different phenotypes, we employed human GEC to investigate the effect of high glucose (22.5 mmol/l), FFA (800 micromol/l), and angiotensin II (ANG II; 10(-7) mol/l) on the genesis of ROS and their effects on endothelial nitric oxide synthase (eNOS), cyclooxygenase-2 (COX-2), and the synthesis of prostaglandins (PGs). We demonstrated that high glucose but not high FFA increased the expression of a dysfunctional eNOS as well as increased ROS from NADPH oxidase (100%) and likely from uncoupled eNOS. ANG II also induced ROS from NADPH oxidase. High glucose and ANG II upregulated (100%) COX-2 via ROS and significantly increased the synthesis of prostacyclin (PGI(2)) by 300%. In contrast, FFA did not upregulate COX-2 but increased PGI(2) (500%). These novel studies are the first in human GEC that characterize the differential role of FFA, hyperglycemia, and ANG II on the genesis of ROS, COX-2, and PGs and their interplay in the early stages of hyperglcyemia.

CKD and poverty: a growing global challenge

Approximately 1.2 billion individuals worldwide live in extreme poverty (< $1/d), and 2.7 billion live in moderate poverty (< $2/d). Poverty is most prevalent in developing countries, but does not spare richer economies, where huge income discrepancies have been reported. Poverty is a major health care marker affecting a number of chronic, communicable, and noncommunicable diseases. Poverty and social deprivation are known to affect the predisposition, diagnosis, and management of chronic diseases; they directly impact on the prevalence of such conditions as obesity, diabetes, and hypertension. Also, growing evidence links poverty to chronic kidney disease (CKD). This may be caused by a direct impact of poverty on CKD or indirectly through the increased health care burden linked to poverty-associated diabetes and hypertension. Furthermore, data have shown that the poor and socially deprived have a greater prevalence of end-stage renal disease. Access to renal care, dialysis, and transplantation may also be affected by social deprivation. Overall, poverty and social deprivation are emerging as major risk markers for CKD in both developing and developed countries. Their impact on CKD warrants careful analysis because it may confound the interpretation of CKD risk factors within communities. This review therefore aims to look at the evidence linking poverty to CKD and its major risk factors, namely, diabetes and hypertension.