Chronic kidney disease in the United States: an underrecognized problem

Echocardiographic features of left ventricular dysfunction and outcomes in chronic kidney disease

OBJECTIVE

Heart failure (HF) imposes a substantial burden and the prevalence of HF is high in patients with chronic kidney disease (CKD). HF results in multiple hospital admissions, but whether HF subtypes worsen long-term outcomes and renal function in patients with CKD remains inconclusive.

METHODS

The study comprised 10 904 patients with CKD aged ≥20 years who underwent echocardiography between 1 January 2011 and 31 December 2018. The patients were stratified into four groups: non-HF, HF with reduced ejection fraction (HFrEF), HF with mildly reduced ejection fraction (HFmrEF) and HF with preserved ejection fraction (HFpEF). The primary end points were all-cause mortality, major adverse cardiovascular events (MACEs) and adverse renal outcomes.

RESULTS

In inverse probability of treatment weighting-adjusted method, the risk of all-cause mortality and MACEs relative to the non-HF group was greatest in the HFrEF group (HR 3.18 (95% CI 2.57 to 3.93) and HR 3.83 (95% CI 3.20 to 4.59)), followed by the HFmrEF (HR 2.75 (95% CI 2.22 to 3.42) and HR 3.08 (95% CI 2.57 to 3.69)) and HFpEF (HR 1.85 (95% CI 1.59 to 2.15) and HR 2.43 (95% CI 2.16 to 2.73) groups. In addition, the HFrEF group had the greatest risks of end-stage renal disease (HR 2.58 (95% CI 1.94 to 3.44)) compared with other groups.

CONCLUSIONS

HF is associated with subsequent worse clinical outcomes, which may be more pronounced in patients with HFrEF, followed by those with HFmrEF and those with HFpEF relative to non-HF group.

The Effectiveness and Safety of Metformin Compared to Sulfonylureas in Diabetic Nephropathy: A Systematic Review

Metformin and sulphonylureas are the most commonly used first-line anti-diabetic agents. However, medical practice guidelines and clinical experience caution against using these drugs in severe diabetic kidney disease. Consequently, the choice of anti-diabetic medicine in various stages of diabetic nephropathy should balance the benefits and risks to the patient. We aim to synthesize available evidence on the effectiveness and safety of metformin concerning sulfonylureas in patients with diabetic renal disease. The COSMOS-E (Guidance on conducting systematic reviews and meta-analyses of observational studies of etiology) and MOOSE (Meta-Analyses and Systematic Reviews of Observational Studies in Epidemiology) guidelines were followed when designing the systematic review. The present study assessed the effectiveness of metformin and sulphonylurea monotherapy regarding renal function. Studies published from 2001 to 2022 were included. We have identified 570 records from PubMed, BioMed Central, LILACS (Literatura Latino-Americana e do Caribe em Ciências da Saúde), ScienceDirect, and PLoS (The Public Library of Science) Medicine databases. Eight cohort studies met the inclusion criteria. All studies reported adjusted hazard ratios with confidence limits. Metformin was found to be more effective in the following events: all-cause mortality, GFR (glomerular filtration rate), ESRD (end-stage renal disease) or death events, one-year risk of death or end-stage renal disease, cardiovascular events, heart failure hospitalization, and hypoglycemic episodes. However, metformin was less effective in acute renal replacement therapy, end-stage renal disease, and/or death, with a one-year risk of acute dialysis. Lactic acidosis was not significant with metformin. The present study recommends that metformin therapy is safe compared to sulfonylurea therapy in diabetic nephropathy patients, provided that the contraindications given in the guidelines are strictly adhered to.

The association between six month intra-dialytic resistance training and muscle strength or physical performance in patients with maintenance hemodialysis: a multicenter retrospective observational study

Background

Reduced muscle strength and physical performance are prevalent in patients of maintenance hemodialysis (MHD), and deleterious changes in these parameters are associated with increased mortality.

Methods

This retrospective observational study included 306 patients, who received a 6-month resistance exercise program during hemodialysis, three times per week on an outpatient basis. The training protocol consisted of two sets of 10 repetitions of knee extension, hip abduction, and hip flexion, using an elastic band in a sitting or supine position. Primary outcome measures included muscle strength, measured by percent knee extension muscle power to dry body weight (pKEMP-dBW), and physical performance, measured by short physical performance battery (SPPB). The adjusted mean differences in these variables during the 6 months were estimated using a multivariate linear regression model.

Results

The mean age with standard deviation was 70 ± 11 years. One hundred and sixty patients (52.3%) were men and the dry weight was 55.6 ± 11.3 kg. Sarcopenia, defined as SPPB ≤8, was present in 21.4% patients. Their hemodialysis adequacy was acceptable, with a Kt/V of 1.65 ± 0.29, and their nutritional status was good, with a normalized protein catabolism rate of 0.89 ± 0.18 g/kg/day. During the 6 months, both pKEMP-dBW and SPPB showed a slight but significant increase with an adjusted mean difference of 2.8 (95% confidence interval 1.3–4.3, p <  0.001) and 0.6 (0.4–0.9, p <  0.001), respectively.

Conclusions

Six-month resistance training was associated with improved muscle strength and physical performance in patients with MHD.

Prevalence, socio-demographic characteristics, and comorbid health conditions in pre-dialysis chronic kidney disease: results from the Manitoba chronic kidney disease cohort

Background

Chronic Kidney Disease (CKD) is common and its prevalence has increased steadily over several decades. Monitoring of rates and severity of CKD across populations is critical for policy development and resource planning. Administrative health data alone has insufficient sensitivity for this purpose, therefore utilizing population level laboratory data and novel methodology is required for population-based surveillance. The aims of this study include a) develop the Manitoba CKD Cohort, b) estimate CKD prevalence, c) identify individuals at high risk of progression to kidney failure and d) determine rates of comorbid health conditions.

Methods

Administrative health and laboratory data from April 1996 to March 2012 were linked from the data repository at the Manitoba Centre for Health Policy. Prevalence was estimated using three methods: a) all CKD cases in administrative and laboratory databases; b) all CKD cases captured only through the laboratory data; c) and the capture-recapture method. Patients were stratified by risk by estimated Glomerular Filtration Rate (eGFR) and albuminuria based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. For comorbid health conditions, the counts were modelled using a Generalized Linear Model (GLM).

Results

The Manitoba CKD Cohort consisted of 55,876 people with CKD. Of these, 18,342 were identified using administrative health data, 27,393 with laboratory data, and 10,141 people were identified in both databases. The CKD prevalence was 5.6% using the standard definition, 10.6% using only people captured by the laboratory data and 10.6% using the capture-recapture method. Of the identified cases, 46% were at high risk of progression to end-stage kidney disease (ESKD), 41% were at low risk and 13% were not classified, due to unavailable laboratory data. High risk cases had a higher burden of comorbid conditions.

Conclusion

This study reports a novel methodology for population based CKD surveillance utilizing a combination of administrative health and laboratory data. High rates of CKD at risk of progression to ESKD have been identified with this approach. Given the high rates of comorbidity and associated healthcare costs, these data can be used to develop a targeted and comprehensive public health surveillance strategy that encompass a range of interrelated chronic diseases.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1058-3) contains supplementary material, which is available to authorized users.

The Cluster of Abnormalities Related to Metabolic Syndrome Is Associated With Reduced Glomerular Filtration Rate and Raised Albuminuria in Patients With Type 2 Diabetes Mellitus

Background

As association of metabolic syndrome (MS) with chronic kidney disease (CKD) has not been extensively studied in patients with type 2 diabetes, we addressed these issues.

Methods

Intrapersonal means of 12 measurements of waist circumference, blood pressure and high-density lipoprotein (HDL) cholesterol and those of six measurements of fasting triglycerides during 12 months were calculated in a cohort of 168 previously reported Japanese patients with type 2 diabetes. Based on these means, MS was diagnosed according to the modified National Cholesterol Education Program Adult Treatment Panel III criteria with the Asian definition of abdominal obesity. CKD was defined as the presence of low estimated glomerular filtration rate (eGFR < 60 mL/min/1.73 m²), albuminuria (urinary albumin/creatinine ratio (ACR) ≥ 30 mg/g) or both.

Results

Of 168 patients, 77 patients (46 %) had MS and 67 (40 %) had CKD. As the number of MS components increased from 1 through 5, the prevalence of albuminuria (9%, 38%, 30%, 41%, and 50%, P < 0.001), low eGFR (0%, 10%, 24%, 22%, and 50%, P < 0.001) and consequently, CKD increased (9%, 41%, 48%, 52%, and 75%, P < 0.001). Urinary ACR increased and eGFR decreased as a function of the number of MS components. As compared to patients without MS, prevalence of low eGFR (26% vs. 7%, P = 0.001) and CKD (52% vs. 30%, P = 0.005) was higher in patients with MS but prevalence of albuminuria did not differ (36% vs. 27%, P = 0.2).

Conclusion

In Japanese patients with type 2 diabetes, the cluster of abnormalities related to MS was associated not only with higher prevalence of albuminuria, reduced kidney function and hence the increase in CKD but also with corresponding changes in urinary ACR and eGFR.

Reducing inappropriate non-steroidal anti-inflammatory prescription in primary care patients with chronic kidney disease

Purpose The purpose of this paper is to reduce inappropriate non-steroidal anti-inflammatory prescribing in primary care patients with chronic kidney disease (CKD). Once diagnosed, CKD management involves delaying progression to end stage renal failure and preventing complications. It is well established that non-steroidal anti-inflammatories have a negative effect on kidney function and consequently, all nephrology consensus groups suggest avoiding this drug class in CKD. Design/methodology/approach The sampling criteria included all practice patients with a known CKD risk factor. This group was refined to include those with an estimated glomerular filtration rate (eGFR)<60 ml/min per 1.73m2 (stage 3 CKD or greater). Phase one analysed how many prescriptions had occurred in this group over the preceding three months. The intervention involved creating an automated alert on at risk patient records if non-steroidal anti-inflammatories were prescribed and discussing the rationale with practice staff. The re-audit phase occurred three months' post intervention. Findings The study revealed 728/7,500 (9.7 per cent) patients at risk from CKD and 158 (2.1 per cent) who were subsequently found to have an eGFR<60 ml/min, indicating=stage 3 CKD. In phase one, 10.2 per cent of at risk patients had received a non-steroidal anti-inflammatory prescription in the preceding three months. Additionally, 6.2 per cent had received non-steroidal anti-inflammatories on repeat prescription. Phase two post intervention revealed a significant 75 per cent reduction in the total non-steroidal anti-inflammatories prescribed and a 90 per cent reduction in repeat non-steroidal anti-inflammatory prescriptions in those with CKD. Originality/value The study significantly reduced non-steroidal anti-inflammatory prescription in those with CKD in primary care settings. It also created a CKD register within the practice and an enduring medication alert system for individuals that risk nephrotoxic non-steroidal anti-inflammatory prescription. It established a safe, reliable and efficient process for reducing morbidity and mortality, improving quality of life and limiting the CKD associated health burden.

Celiac disease and the risk of kidney diseases: A systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Previous epidemiologic studies attempting to demonstrate the risk of kidney diseases among patients with celiac disease (CD) have yielded inconsistent results. This meta-analysis was conducted with the aims to summarize all available evidence.

METHODS

A literature search was performed using MEDLINE and EMBASE from inception to May 2016. Studies that provided relative risks, odd ratios, or hazard ratios examining the risk of kidney diseases among patients with CD versus individuals without CD were included. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Eight studies met our eligibility criteria and were included in our analysis. A pooled RR of overall kidney diseases in patients with CD was 2.01 (95% CI, 1.44-2.81, I²=76%). The pooled RR of end-stage renal disease in patients with CD was 2.57 (95% CI, 2.03-3.24). Subgroup analyses showed that significant risks were increased for diabetic nephropathy (pooled RR of 1.49, 95% CI, 1.09-2.02) and IgA nephropathy (pooled RR of 2.62, 95% CI, 1.27-5.42) in patients with CD.

CONCLUSIONS

Our study demonstrates a significantly increased risk of kidney diseases among patients with CD. These findings may influence clinical management and primary prevention of kidney diseases in patients with CD.

The putative role of MALDI-MSI in the study of Membranous Nephropathy

Membranous Nephropathy (MN) is an immunocomplex mediated renal disease that represents one of the most frequent glomerulopathies worldwide. This glomerular disease can manifest as primary (idiopathic) or secondary and this distinction is crucial when choosing the most appropriate course of treatment. In secondary cases, the best strategy involves treating the underlying disease, whereas in primary forms, the identification of confirmatory markers of the idiopathic etiology underlining the process is requested by clinicians. Among those currently reported, the positivity to circulating antigens (PLA2R, IgG4 and THSD7A) was demonstrated in approximately 75% of iMN patients, while approximately 1 in 4 patients with iMN still lack a putative diagnostic marker. Ultimately, the discovery of biomarkers to help further stratify these two different forms of glomerulopathy seems mandatory. Here, MALDI-MSI was applied to FFPE renal biopsies from histologically diagnosed primary and secondary MN patients (n=20) in order to detect alterations in their tissue proteome. MALDI-MSI was able to generate molecular signatures of primary and secondary MN, with one particular signal (m/z 1459), identified as Serine/threonine-protein kinase MRCK gamma, being over-expressed in the glomeruli of primary MN patients with respect to secondary MN. Furthermore, a number of signals that could differentiate the different forms of iMN that were positive to PLA2R or IgG4 were detected, as well as a further set of signals (m/z 1094, 1116, 1381 and 1459) that could distinguish these patients from those who were negative to both. These signals could potentially represent future targets for the further stratification of iMN patients. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

Association of Metabolic Syndrome with Chronic Kidney Disease in Elderly Japanese Women: Comparison by Estimation of Glomerular Filtration Rate from Creatinine, Cystatin C, and Both

BACKGROUND

Associations between metabolic syndrome (MetS) and chronic kidney disease (CKD) has not been extensively studied in elderly Asians, who in general have lower body mass index (BMI) than European populations.

METHODS

A cross-sectional analysis was conducted including 159 community-living elderly Japanese women. MetS was defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria, but using a BMI ≥25 kg/m(2) instead of waist circumference and renal function was assessed according to the Kidney Disease Outcomes Quality Initiative CKD classification. Creatinine-based and cystatin C-based estimated glomerular filtration rate (eGFR) and the average of the two eGFRS were used.

RESULTS

Prevalence of CKD was much higher when creatinine-based eGFR was used than the prevalence obtained when cystatin-C based equations were used (46.5% vs. 12.6%, P < 0.001). Eighteen (11.3%) women met MetS criteria. Both the presence of MetS and the number of MetS components were associated with higher prevalence of CKD using the average eGFR (all P < 0.05) but not using creatinine-based (P = 0.86) and cystatin C-based (P = 0.12) eGFR alone. Lower average eGFR and higher prevalence of CKD using average eGFR were evident in even women with only one MetS component, 89% of whom had elevated blood pressure.

CONCLUSIONS

Prevalence of CKD varied substantially depending on the used equation. In nonobese, elderly Japanese women, both the presence of MetS and the number of MetS components were associated with higher prevalence of CKD and elevated blood pressure may play an important role in these associations. These findings should be confirmed in studies employing more participants with MetS diagnosed using standard criteria (waist circumference instead of BMI).

Prevalence of chronic kidney disease and its association with cardio-metabolic risk factors in the adult Romanian population: the PREDATORR study

PURPOSE

PREDATORR is the first national study analyzing the prevalence of chronic kidney disease and its prognosis and association with socio-demographic, cardio-metabolic and lifestyle risk factors in the adult Romanian population.

METHODS

Chronic kidney disease was defined according to the KDIGO 2012 criteria as an estimated glomerular filtration rate <60 mL/min/1.73 m(2) and/or urinary albumin-to-creatinine ratio ≥30 mg/g. The socio-demographic, lifestyle and anamnestic data were collected through interviewer-administered questionnaires. Physical examination and biochemical assays were also performed.

RESULTS

This cross-sectional study conducted between December 2012 and February 2014 in Romania included 2717 adults. The overall age- and sex-adjusted prevalence of chronic kidney disease was 6.74 % (95 %CI 5.60-7.88 %), of which 3.31 % (2.50-4.13 %) had only reduced kidney function (estimated glomerular filtration rate <60 mL/min/1.73 m(2)), 2.98 % (2.21-3.76 %) had only albuminuria, and 0.45 % (0.14-0.74 %) had both. The prevalence of chronic kidney disease increased with age and was similar in women and in men. Age, hyperuricemia, impaired glucose regulation (diabetes/prediabetes), hypertriglyceridemia and a family history of renal disease were independent risk factors for the presence of chronic kidney disease.

CONCLUSIONS

The PREDATORR study showed a high prevalence of chronic kidney disease in the adult Romanian population providing data on its prognosis and association with several cardio-metabolic risk factors.

Early stage of vascular disease and diabetic kidney disease: an under-recognized entity

Early stage of vascular disease and diabetic kidney disease (DKD stages 1 and 2) has been under-recognized, under common practice worldwide. The lack of sensitive diagnostic marker leads to late diagnosis and a progression of underlying vascular disease associated with chronic renal ischemia, which eventually intensifies the magnitude of DKD damage. Treatment at this late stage fails to correct the renal ischemia, or restore renal function, due to the altered vascular homeostasis associated with an impaired nitric oxide production. In contrast to the above information, early recognition of vascular disease and DKD with sensitive diagnostic markers would be able to implement an effective prevention of progression of vascular disease and DKD. Treatment at early stage under environment favorable for adequate vascular homeostasis is able to correct the renal ischemia and improve the renal function.

Tobacco and end stage renal disease: a multicenter, cross-sectional study in Argentinian Northern Patagonia

BACKGROUND

Smoking and chronic kidney disease are major public health problems with common features -high prevalence and mortality, high cardiovascular risk, gender differences and high prevalence in low income people-, but the link between them is poorly recognized. Our objectives were to investigate the exposure of dialysis patients to tobacco and to know their smoking behavior.

METHODS

We performed a multicenter, cross-sectional study in nine dialysis units in the Argentinian Northern Patagonia. We investigated smoker status, lifetime tobacco consumption, current tobacco use, breath carbon monoxide and % carboxyhaemoglobin. Fagerström and Richmond tests were performed for active smokers.

STATISTICAL ANALYSIS

one way ANOVA and Tukey's test for post hoc test. For exploratory analysis, frequency tables through chi-square distribution and single correspondence analysis were performed.

RESULTS

Six hundred thirty six patients (60.9 % males, 39.1 % females) were interviewed. Almost 70 % of them had had tobacco exposure. Excluding light smokers, the lifetime consumption was significantly different (p = 0.0052) between sexes (33.1 ± 2.4 pack/years in males and 18.2 ± 2.1 pack/years in females) The distribution of etiologies changed significantly (χ (2) p < 0.0001) with smoker status and the dose of tobacco smoking, with an increase in the diagnosis of nephrosclerosis in patients with high and very high lifetime consumption (from 16.1 % in non-smokers to 28.2 and 27 % respectively), and in passive smokers (from 16.1 to 27.3 %). The male preponderance of end-stage renal disease disappeared when only non-smokers were considered and grew with the increase in the lifetime consumption. Active smokers have small consumption, both low CO level and % COHb, low dependence and a good motivation to quit, but a high lifetime consumption.

CONCLUSIONS

Exposure of dialysis patients to tobacco is high and could be related to the progression to the final stage of the renal disease. It seems that tobacco renal damage is mostly hidden in the diagnosis of nephrosclerosis. The gender difference observed in these patients could also have a nexus with the men's higher tobacco exposure. Active smokers have a low current consumption but a high lifetime tobacco dose.

The role of endoglin in kidney fibrosis

Tubulointerstitial fibrosis and glomerulosclerosis, are a major feature of end stage chronic kidney disease (CKD), characterised by an excessive accumulation of extracellular matrix (ECM) proteins. Transforming growth factor beta-1 (TGF-β1) is a cytokine with an important role in many steps of renal fibrosis such as myofibroblast activation and proliferation, ECM protein synthesis and inflammatory cell infiltration. Endoglin is a TGF-β co-receptor that modulates TGF-β responses in different cell types. In numerous cells types, such as mesangial cells or myoblasts, endoglin regulates negatively TGF-β-induced ECM protein expression. However, recently it has been demonstrated that 'in vivo' endoglin promotes fibrotic responses. Furthermore, several studies have demonstrated an increase of endoglin expression in experimental models of renal fibrosis in the kidney and other tissues. Nevertheless, the role of endoglin in renal fibrosis development is unclear and a question arises: Does endoglin protect against renal fibrosis or promotes its development? The purpose of this review is to critically analyse the recent knowledge relating to endoglin and renal fibrosis. Knowledge of endoglin role in this pathology is necessary to consider endoglin as a possible therapeutic target against renal fibrosis.

p-Cresyl sulfate, a uremic toxin, causes vascular endothelial and smooth muscle cell damages by inducing oxidative stress

The major cause of death in patients with chronic kidney disease (CKD) is cardiovascular disease. Here, p-Cresyl sulfate (PCS), a uremic toxin, is considered to be a risk factor for cardiovascular disease in CKD. However, our understanding of the vascular toxicity induced by PCS and its mechanism is incomplete. The purpose of this study was to determine whether PCS enhances the production of reactive oxygen species (ROS) in vascular endothelial and smooth muscle cells, resulting in cytotoxicity. PCS exhibited pro-oxidant properties in human umbilical vein endothelial cells (HUVEC) and aortic smooth muscle cells (HASMC) by enhancing NADPH oxidase expression. PCS also up-regulates the mRNA levels and the protein secretion of monocyte chemotactic protein-1 (MCP-1) in HUVEC. In HASMC, PCS increased the mRNA levels of alkaline phosphatase (ALP), osteopontin (OPN), core-binding factor alpha 1, and ALP activity. The knockdown of Nox4, a subunit of NADPH oxidase, suppressed the cell toxicity induced by PCS. The vascular damage induced by PCS was largely suppressed in the presence of probenecid, an inhibitor of organic anion transporters (OAT). In PCS-overloaded 5/6-nephrectomized rats, plasma MCP-1 levels, OPN expression, and ALP activity of the aortic arch were increased, accompanied by the induction of Nox4 expression. Collectively, the vascular toxicity of PCS can be attributed to its intracellular accumulation via OAT, which results in an enhanced NADPH oxidase expression and increased ROS production. In conclusion, we found for the first time that PCS could play an important role in the development of cardiovascular disease by inducing vascular toxicity in the CKD condition.

The association of leptin and homocysteine with renal function impairment in a population of Taiwanese adults

BACKGROUND & AIMS

Higher levels of leptin and homocysteine (Hcy) have been evaluated as risk factors of chronic kidney disease in patients and general population. The aim of this study was to examine gender differences in the associations of leptin and Hcy levels and renal function a representative healthy young population in Taiwan.

METHODS

The participants aged ≥18 years who underwent health examinations were included and categorized into three groups by gender-specific tertiles of leptin and Hcy levels. Estimated glomerular filtration rates (eGFR) were estimated according to the modified equation of Modification of Diet in Renal Disease (MDRD).

RESULTS

A higher mean Hcy level was found in male subjects than females. Mean values of metabolic syndrome risk factors significantly elevated with increasing leptin levels in both genders. Both male and female subjects with higher plasma Hcy levels were more likely to have a lower eGFR. Plasma Hcy levels were significantly negatively correlated with eGFR in linear regression models adjusted for age and smoking. The associations persisted even after mean arterial pressure and fasting plasma glucose were included for adjustments both genders. Plasma Hcy level was negatively associated eGFR and the association was more profound for females.

CONCLUSIONS

Leptin levels did not reveal strong or consistent evidence to support a significant association with eGFR. Hcy had a more decisive effect on renal function impairment than leptin and may be considered a more sensitive biomarker for Taiwanese adults.

Comparison of chronic kidney disease prevalence examined by the chronic kidney disease epidemiology collaboration equation with that by the modification of diet in renal disease equation in Korean adult population

BACKGROUND

The new estimated glomerular filtration (eGFR) equation, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, was recently introduced. We compared the prevalence of CKD examined by the CKD-EPI equation with that by the Modification of Diet in Renal Disease (MDRD) equation.

METHODS

We analyzed the data from a total of 14,605 Korean adults (age ≥20 years), who were enrolled in the Korean National Health and Nutrition Examination Survey in 2007, 2009, and 2010. CKD stages 1 and 2 were defined as eGFR ≥60 mL/min/1.73 m(2) with proteinuria measured by dipstick. CKD stages 3-5 were defined as eGFR <60 mL/min/1.73 m(2) .

RESULTS

The eGFRs calculated by the CKD-EPI equation were higher than those calculated by the MDRD equation (P < 0.001), especially in women and young people. The prevalence of CKD stages 3-5 calculated by the MDRD equation was 6.8%, 3.0%, and 3.0% in 2007, 2009, and 2010, respectively. The prevalence of CKD stages 3-5 calculated by CKD-EPI equation was 7.7%, 2.7%, and 2.6% in 2007, 2009, and 2010, respectively. When defining the CKD using the CKD-EPI equation, 55 (32.7%) of 350 cases were reclassified into more advanced stages and 295 cases (67.3%) were reclassified into less-advanced stages.

CONCLUSION

The CKD-EPI equation caused an overall low prevalence of CKD compared to the MDRD. Therefore, CKD-EPI equation might be helpful to prevent an overestimation of CKD.

Excisional wound healing is delayed in a murine model of chronic kidney disease

Background

Approximately 15% of the United States population suffers from chronic kidney disease (CKD), often demonstrating an associated impairment in wound healing. This study outlines the development of a surgical murine model of CKD in order to investigate the mechanisms underlying this impairment.

Methods

CKD was induced in mice by partial cauterization of one kidney cortex and contralateral nephrectomy, modifying a previously published technique. After a minimum of 6-weeks, splinted, dorsal excisional wounds were created to permit assessment of wound healing parameters. Wounds were harvested on postoperative days (POD) 0, 3, 7, and 14 for histological, immunofluorescent, and quantitative PCR (qPCR).

Results

CKD mice exhibited deranged blood chemistry and hematology profiles, including profound uremia and anemia. Significant decreases in re-epithelialization and granulation tissue deposition rates were found in uremic mice wounds relative to controls. On immunofluorescent analysis, uremic mice demonstrated significant reductions in cellular proliferation (BrdU) and angiogenesis (CD31), with a concurrent increase in inflammation (CD45) as compared to controls. CKD mice also displayed differential expression of wound healing-related genes (VEGF, IL-1β, eNOS, iNOS) on qPCR.

Conclusions

These findings represent the first reported investigation of cutaneous healing in a CKD animal model. Ongoing studies of this significantly delayed wound healing phenotype include the establishment of renal failure model in diabetic strains to study the combined effects of CKD and diabetes.

Natural history of older adults with impaired kidney function: the InCHIANTI study

The aim of this study was to assess the kidney function of an older community-dwelling population at baseline and appraise its evolution after 3 years of follow-up in terms of chronic kidney disease (CKD) stage progression, magnitude of glomerular filtration rate (GFR) changes, and value of serum creatinine. This was a prospective population-based study of 676 Italian participants, aged 65 years and older. GFR was estimated using the Cockcroft-Gault equation and the Modification of Diet in Renal Disease Study equation. Using the Cockcroft-Gault equation. A total of 33% of participants had criteria of CKD (GFR < 60 mL/min) at baseline; among them, the majority remained stable, 10% improved, and 7% progressed to more severe CKD stages at follow-up. Loss of GFR in participants with GFR < 60 mL/min was significantly lower (1.4 mL/min per year) than in participants with GFR ≥ 60 mL/min (3.3 mL/min per year) at baseline. Most participants classified with CKD stage 2 (GFR 60-89 mL/min) or stage 3 (GFR 30-59 mL/min) at baseline did not change stage, whereas 55% of people with CKD stage 1 (GFR > 90 mL/min) at baseline worsened to stage 2 and 10% worsened to stage 3. An abnormal high level of serum creatinine at baseline did not help to predict who might worsen at follow-up. Older people with CKD displayed a low progression of renal disease and therefore are at higher risk for co-morbidities related to CKD than for progression to end-stage renal disease.

Glycemic and lipidic profile in diabetic patients undergoing dialysis

OBJECTIVE

The aim of this study is to assess the clinical care pattern and to compare the lipid and glycemic profile in a group of diabetic patients undergoing both hemodialysis (HD) and peritoneal dialysis (PD) and to correlate these data using biomarkers of cardiovascular risk.

SUBJECTS AND METHODS

The first phase consisted in performing a survey on demographic data, questions about the medical team and glycemic control. In the second phase, patients were assessed through laboratorial data on their glycemic and lipid profile at a single center for HD and PD.

RESULTS

91 patients was the total population; 70 patients (77%) answered the survey; 66 patients (94%) considered the nephrologist the physician responsible for caring for their glycemic control. Second phase: 59 patients were assessed, 29 undergoing HD and 30 undergoing PD. Fifty-seven percent of the patients had HbA1c above 7%; the level of glycemic markers in patients undergoing peritoneal dialysis was significantly higher than in patients undergoing hemodialysis: HbA1c (9.37 ± 0.5) vs. (7.37 ± 0.49) p < 0.01; fasting glycemia (170 ± 15) vs. (126 ± 15) mg/dL p < 0.05. We found a positive correlation between HbA1c and hyperfibrinogenemia (r = 0.4437, p < 0.0005).

CONCLUSIONS

The data reveal that glycemic control in diabetic patients undergoing renal replacement therapy (RRT) is neglected. Peritoneal dialysis is related to the worst level of glycemic markers, possibly due to the glucose content in the dialysis solution, and higher levels from HbA1c have a positive correlation with hyperfibrinogenesis in this population.

Long-term high intake of whole proteins results in renal damage in pigs

Despite evidence of potential antiobesity effects of high-protein (HP) diets, the impact of consuming diets with protein levels at the upper limit of the acceptable macronutrient distribution range (AMDR) on kidney health is unknown. To test whether HP diets affect renal health, whole plant and animal proteins in proportions that mimicked human diets were given to pigs, because their kidneys have a similar anatomy and function to those of humans. Adult female pigs received either normal-protein (NP) or HP (15 or 35% of energy from protein, respectively) isocaloric diets for either 4 or 8 mo. The higher protein in the HP diet was achieved by increasing egg and dairy proteins. Although there were initial differences in body weight and composition, after 8 mo these were similar in pigs consuming the NP and HP diets. The HP compared with NP diet, however, resulted in enlarged kidneys at both 4 and 8 mo. Renal and glomerular volumes were 60-70% higher by the end of the study. These enlarged kidneys had greater evidence of histological damage, with 55% more fibrosis and 30% more glomerulosclerosis. Renal monocyte chemoattractant protein-1 levels also were 22% higher in pigs given the HP diet. Plasma homocysteine levels were higher in the HP pigs at 4 mo and continued to be elevated by 35% at 8 mo of feeding. These findings suggest that long-term intakes of protein at the upper limit of the AMDR from whole protein sources may compromise renal health.

Chronic kidney disease and end-stage renal disease-a review produced to contribute to the report 'the status of health in the European union: towards a healthier Europe'

The Report on the Status of Health in the European Union (EUGLOREH) is a project aimed at describing health problems in member states of the European Community. This project is an effort of more than 170 European experts and the collaboration of the health authorities or institutions from all EU Member States, major intergovernmental, International and European Organizations and Agencies. In this report, for the first time special emphasis is given to chronic diseases. Chronic kidney disease (CKD) is increasingly recognized as a major public health problem. However, with some notable exceptions, until now this disease has received scarce attention both at European level and at member states level. In 2007, the ERA-EDTA Registry was invited to contribute to EUGLOREH. The Registry made a major effort to gather published and unpublished information on the epidemiology of CKD and ESRD and to provide a comprehensive overview on CKD and ESRD in European countries. The review was completed in early 2008 and included into the final EUGLOREH published in the WEB as of 20 March 2009.

Bowel preparation in CT colonography: electrolyte and renal function disturbances in the frail and elderly patient

PURPOSE

Elderly patients are at increased risk of biochemical disturbances secondary to cathartic medications. This study investigates the renal function, electrolyte and clinical disturbances associated with CT colonography (CTC) with sodium picosulphate-magnesium citrate (SPS-MC) in a subgroup of frail, elderly patients.

METHODS

Patients aged over 70 years considered at risk of complication during SPS-MC administration by a physician specialised in care of the elderly were included in this retrospective study. Biochemical parameters pre- and post-CTC and the presence of co-morbidities were recorded. Imaging findings and quality of bowel preparation at CTC were graded by consensus by two radiologists.

RESULTS

Of the 72 patients 56% had co-morbidities that caution the use of SPS-MC. No significant changes in serum urea, sodium, potassium or estimated glomerular filtration rate (eGFR) occurred post-CTC (p > 0.10). Serum magnesium increased by 0.11 mmol/L in 14 patients (p = 0.03) without clinical sequelae. Good overall preparation was achieved in 88% of patients, allowing confident identification of signs of colonic neoplasia in 20 patients (27%). A mild increase in serum magnesium but no other significant biochemical disturbance was observed.

CONCLUSION

In our group CTC with SPS-MC was safe and effective; however, we advise an alternate preparation be considered in patients with decreased renal function due to decreased magnesium clearance.

Fisher-Lewis kidney transplantation model as a tool for investigation of transplantation-induced cardiomyopathy

BACKGROUND

Cardiovascular disease is a major cause of death after kidney transplantation; thus, cardiovascular protection is a major concern in transplant recipients. Data about cardiac characteristics from animal models after kidney transplantation are lacking. Therefore, we investigated cardiac structure and function in a model of chronic allograft injury.

METHODS

Kidneys from Fisher 344 rats were orthotopically transplanted into Lewis rats. Eight recipient rats were treated with placebo or an angiotensin II type-1 receptor blocker (AT1RB; candesartan cilexitil, 5 mg/kg/d) for 24 weeks posttransplantation, and 8 untreated matched Lewis rats were used as healthy controls. Echocardiography was performed at 24 weeks posttransplantation to measure ejection fraction, fractional shortening, and left ventricular mass, in triplicate. Proteinuria at 24 hours was determined, and after harvesting, the heart weight-body weight ratio (HW/BW) was measured.

RESULTS

At 24 weeks posttransplantation, renal transplant-recipient rats demonstrated a significantly decreased ejection fraction (mean [SD], 58.9% [3.2%] vs 70.7% [2.1%]) and fractional shortening (29.8% [2.0%] vs 38.3% [2.0%]) and increased HW/BW and left ventricular mass (7.7 [0.2] cm(3) vs 6.7 [0.2] cm(3)) compared with healthy control rats. The HW/BW and left ventricular mass were significantly ameliorated by AT1RB compared with placebo-treated transplant-recipient rats (6.8 [0.2] cm(3) vs 7.7 [0.2] cm(3)). In addition, decreased proteinuria was evident after AT1RB.

CONCLUSION

The Fisher-Lewis rat kidney transplantation model resulted in cardiac hypertrophy and decreased cardiac function. AT1RB normalized cardiac hypertrophy without improving function. These findings demonstrate that the Fisher-Lewis rat renal transplantation model can be used to investigate transplantation-induced cardiomyopathy.

Chronic kidney disease Markov model comparing paricalcitol to calcitriol for secondary hyperparathyroidism: a US perspective

OBJECTIVE

The objective of this study was to determine the cost effectiveness of paricalcitol versus calcitriol for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease in the United States setting.

METHODS

A Markov process model was developed employing data sources from the published literature, paricalcitol clinical trials and observational studies, official US price/tariff lists and national population statistics. The comparator was calcitriol, a non-selective vitamin D receptor activator (VDRA) medication. The primary perspective of the study was that of the third-party payer in the US. The efficacy outcomes (reduction in secondary hyperparathyroidism (SHPT), reduction in proteinuria, complications and mortality) were extrapolated to: number of life-years gained (LYG) and number of quality-adjusted life-years (QALYs). Clinical and economic outcomes were discounted at 3.5%.

RESULTS

The reference case analysis was a 10-year time horizon based on a comparison of paricalcitol with calcitriol, which is started in chronic kidney disease (CKD) stage 3 and continued in CKD stage 4 and CKD stage 5. The use of paricalcitol leads to a cost saving of US$1941. The inclusion of indirect costs leads to a cost saving of US$2528. The use of paricalcitol leads to an increase in life-years gained (0.47 years) and a gain in QALYs (0.43). The use of paricalcitol results in a dominant outcome from the perspective of the third-party payer, as well as from the societal perspective. One-way sensitivity analyses and probabilistic sensitivity analyses confirmed the robustness of the model.

CONCLUSION

This model showed that the favorable clinical benefit of paricalcitol results in positive short and long-term health economic benefits. This study suggests that the use of paricalcitol in patients with early chronic kidney disease may be cost-effective from the third-party payer perspective in the US versus calcitriol. Additional comparative studies are necessary to validate these results.

Albuminuria and chronic kidney disease in association with the metabolic syndrome

Chronic kidney disease is a worldwide public health problem because it is an important risk factor for cardiovascular disease and premature death. The metabolic syndrome, which is characterized by abdominal obesity, high blood pressure, impaired glucose tolerance, and dyslipidemia, is also an increasingly common disorder and a major risk factor for diabetes and cardiovascular disease. A close association has been found between the metabolic syndrome and the risk for developing renal impairment, clinically expressed in the form of microalbuminuria or chronic kidney disease. Several potential mechanisms, including insulin resistance, renal atherosclerosis, and inflammation, induce the deterioration of renal function. Despite the close association between the metabolic syndrome and renal impairment, it is still unclear whether and to what extent treating the metabolic syndrome will prevent renal impairment. A clinical trial is needed to clarify whether the effect of preventing and treating metabolic syndrome components will result in improved renal prognosis.

Magnitude of underascertainment of impaired kidney function in older adults with normal serum creatinine

OBJECTIVES

To estimate in a community-dwelling elderly population the magnitude of renal function misclassification, occurring when persons with normal serum creatinine have reduced glomerular filtration rate (GFR), and to describe the participant characteristics related to misclassification.

DESIGN

Cross-sectional.

SETTING

Population-based study of older Italian people.

PARTICIPANTS

Six hundred sixty participants aged 65 to 92 with normal serum creatinine.

MEASUREMENTS

GFR was estimated using the Cockcroft-Gault equation and creatinine clearance (CrCl) calculated from 24-hour urine collection.

RESULTS

In participants with normal serum creatinine, 39% and 25% had moderate renal function impairment (GFR<60 mL/min) according to the Cockcroft-Gault equation and CrCl calculation, respectively. Prevalence of moderate renal impairment in those aged 65 to 74, 75 to 84, and 85 and older was 18.6%, 58.3%, and 96.8%, respectively (P for trend <.001) according to the Cockcroft-Gault equation, and 15%, 35.7%, and 58.7%, respectively (P for trend <.001) based on the CrCl calculation. In addition, female sex (P<.001) and normal or underweight (P<.05) were factors associated with high risk of misclassification.

CONCLUSION

Serum creatinine alone is one of the most widely used methods of assessing renal function in clinical practice despite its well-known poor correlation with GFR. A large proportion of older persons with impaired renal function are not diagnosed if clinicians rely solely on normal serum creatinine as evidence of normal renal function. Opportunities may be missed for slowing progression of kidney disease, managing comorbidities and complications related to renal impairment, and adjusting drug dosage for renal function.

Renal insufficiency in elderly cancer patients: International Society of Geriatric Oncology clinical practice recommendations

BACKGROUND

Elderly cancer patients commonly have renal function decline. This warrants particular caution during the administration of renally excreted cancer drugs or those with established nephrotoxicity.

DESIGN

An International Society for Geriatric Oncology task force was formed to discuss treatment recommendations for this group of patients.

RESULTS

Before drug therapy, the assessment and optimization of hydration status and evaluation of renal function is required. Serum creatinine alone is insufficient as a means of evaluating renal function, and creatinine clearance should at least be calculated in every patient by the abbreviated modification of diet in renal disease or Cockcroft-Gault equations. In the extremes of obesity and cachexia and at very high and low creatinine values, no single tool is really accurate. In these patients, the best estimate of glomerular filtration rate is provided by direct methods such as (51)Cr-EDTA or inulin measurement. Within each drug class, preference may be given to agents less likely to be influenced by renal clearance, which are minimally nephrotoxic, or for which appropriate methods of prevention for renal toxicity exist. Coadministration of known nephrotoxic drugs should be avoided or minimized.

CONCLUSIONS

Future trials should be designed to present data in a way that allows evaluation of the contribution of renal function to toxicity and efficacy.

Remifentanil or sufentanil for coronary surgery

BACKGROUND AND OBJECTIVE

High-dose opioid anaesthesia contributes to decreasing metabolic and hormonal stress responses in patients undergoing cardiac surgery. However, the increase in context-sensitive half-life of opioids given as a high-dose regimen can affect postoperative respiratory recovery. In contrast, remifentanil can be given in high doses without prolonging context-sensitive half-life due to its rapid metabolism. Therefore, we performed a prospective, randomized trial to compare anaesthesia consisting of propofol/remifentanil or propofol/sufentanil with regard to postoperative respiratory function and outcome.

METHODS

Patients undergoing coronary artery bypass grafting were randomized to a propofol/remifentanil (0.5-1.0 microg kg(-1) min(-1)) or propofol/sufentanil (30-40 ng kg(-1) min(-1)) based anaesthetic. Carbon dioxide response, forced expiratory volume in one second, vital capacity, and functional residual capacity were measured 1 day prior to the operation, 1 h before extubation, 1, 24 and 72 h after extubation. In addition, the incidence of atelectasis, pulmonary infiltrates, intensive care unit and postoperative length of stay were compared. Patients and physicians were blinded to the treatment group.

RESULTS

Twenty-five patients in each treatment group completed the study. There was no difference between patients of the treatment groups regarding demographics, risk- or pain scores. In all patients, carbon dioxide response, forced expiratory volume in one second, vital capacity and functional residual capacity were decreased postoperatively compared to baseline. Patients randomized to remifentanil had less depression of carbon dioxide response, less atelectasis and shorter postoperative length of stay (12 d vs. 10 d) than after sufentanil (P < 0.05).

CONCLUSIONS

Intraoperative use of high-dose remifentanil for coronary artery bypass grafting may be associated with improved recovery of pulmonary function and shorter postoperative hospital length of stay than sufentanil.

Metabolic syndrome and CKD in a general Japanese population: the Hisayama Study

BACKGROUND

Metabolic syndrome has been linked with various atherosclerotic diseases, but has not been evaluated sufficiently as a risk factor for the development of chronic kidney disease (CKD) in the general population.

METHODS

We followed up 1,440 community-dwelling individuals without CKD aged 40 years or older for 5 years and examined the effects of metabolic syndrome, defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria, on the development of CKD.

RESULTS

During follow-up, 88 subjects experienced CKD. The age- and sex-adjusted 5-year cumulative incidence of CKD was significantly greater in subjects with than without metabolic syndrome (10.6% versus 4.8%; P < 0.01). In multivariate analysis, even after adjustment for other confounding factors, including insulinemia, metabolic syndrome remained an independent risk factor for the occurrence of CKD (odds ratio, 2.08; 95% confidence interval [CI], 1.23 to 3.52). Compared with subjects with 1 or fewer metabolic syndrome component, multivariate-adjusted odd ratios for CKD in subjects with 2, 3, and 4 or more metabolic syndrome components were 1.13 (95% CI, 0.60 to 2.12), 1.90 (95% CI, 0.98 to 3.69), and 2.79 (95% CI, 1.32 to 5.90), respectively. The rate of change in kidney function during 5 years decreased significantly in subjects with 4 or more metabolic syndrome components compared with those with 1 or fewer component in the age group of 40 to 59 years, whereas it also was significantly low in subjects with 3 metabolic syndrome components in the group aged 60 years or older.

CONCLUSION

Our findings suggest that metabolic syndrome is a significant risk factor for the development of CKD in the general population.

Prospective nutritional surveillance using bioelectrical impedance in chronic kidney disease patients

Malnutrition is a well-known risk factor influencing survival in chronic maintenance dialysis patients. Chronic kidney disease (CKD) patients are also predisposed to malnutrition because of dietary restrictions and the catabolic effects of uremia. Therefore, a significant degree of malnutrition may be present before the initiation of renal replacement therapy. We consequently initiated a prospective evaluation of subjects attending the CKD clinic, where all patients are seen by a renal dietitian and nutritional, biochemical, and bioimpedance parameters are measured every 3 months. A total of 40 patients have completed 9 months of follow-up and are the subject of this report. Their mean age is 65 +/- 12 years, 48% female, 68% black, and 58% diabetic patients. The glomerular filtration rate did not change during follow-up (36 +/- 12 versus 34 +/- 14 mL/min/1.72 m 2 , at baseline and 9 months, respectively). Similarly, no differences between baseline and 9 months were noted in weight (88.0 +/- 20.3 versus 86.8 +/- 18.7 kg, respectively) or body mass index (30.6 +/- 5.8 versus 30.2 +/- 5.4 kg/m 2 , respectively). In addition, no differences between baseline and 9 months were noted in total body water (44.4 +/- 11.4 versus 44.6 +/- 10.8 L, respectively), body cell mass (25.3 +/- 7.4 versus 25.2 +/- 7.0 kg, respectively), and fat-free mass (59.2 +/- 16.6 versus 59.4 +/- 15.7 kg, respectively). The bioimpedance vector decreased with time in 25 subjects (62%), indicating a state of overhydration. Subjects were further analyzed by vector category. Body cell mass did not change in either group. As expected, total body water increased in the group with a decreasing bioimpedance vector. Because body cell mass did not increase, the greater total body water reflected an increase in extracellular volume (edema). In the group with stable vectors, no changes were noted with time in weight or total body water. These results indicate that CKD patients with stable renal function following a judicious dietary protein intake (0.6 to 0.8 g/kg normalized body weight/day) have no loss of body cell mass or fat-free mass over a 9-month period. Of note, a high proportion of patients (62%) developed clinically unrecognized fluid retention, which is promptly identified by a decreasing bioimpedance vector.

When chronic kidney disease becomes advanced. Guidelines for care in the emergency department and hospital

Patients with advanced chronic kidney disease or end-stage renal disease live with a serious condition that often necessitates visits to an emergency department and subsequent hospitalization. Often, physicians in these settings are not trained in nephrology. Emergency department physicians and other nonnephrologists who regularly manage advanced chronic kidney disease and end-stage renal disease need to follow several basic principles to provide excellent care to patients with these conditions.

De novo congestive heart failure after kidney transplantation: a common condition with poor prognostic implications

BACKGROUND

We aim to describe the risk, predictors, and outcomes associated with de novo congestive heart failure (CHF) after kidney transplantation.

METHODS

We used registry data from the US Renal Data System to retrospectively investigate de novo CHF in adult Medicare-insured transplant recipients and wait-listed candidates in 1995 to 2001. Heart failure was ascertained from inpatient and outpatient billing records, and participants were followed up until loss of Medicare or December 31, 2001. We used extended Cox hazards analysis to identify independent correlates of posttransplantation de novo CHF (adjusted hazard ratio [AHR], 95% confidence interval [CI]) and examine de novo CHF as a predictor of death and graft loss after transplantation.

RESULTS

In 27,011 transplant recipients, cumulative incidences of de novo CHF were 10.2% (95% CI, 9.8 to 10.6) and 18.3% (95% CI, 17.8 to 18.9) at 12 and 36 months and decreased to less than the demographic-adjusted incidence on the waiting list beyond the early posttransplantation period. Risk factors for de novo CHF included older recipient age, female sex, unemployed status at transplantation, pretransplantation comorbidities (anemia, diabetes mellitus, myocardial infarction, angina, cardiac arrhythmia, and peripheral vascular disease), transplant from older donors, donor cardiovascular death, and delayed graft function. We identified pretransplantation obesity, smoking, and posttransplantation complications, including hypertension, anemia, new-onset diabetes, myocardial infarction, and graft failure, as potentially modifiable correlates of de novo CHF. In separate analyses, de novo CHF predicted death (AHR, 2.6; 95% CI, 2.4 to 2.9) and death-censored graft failure (AHR, 2.7; 95% CI, 2.4 to 3.0).

CONCLUSION

Although associations may not reflect causality, identification of potentially mutable de novo CHF risk factors suggests targets for improving outcomes that should be evaluated prospectively.

Kidney in early atherosclerosis

Atherosclerosis represents one of the major causes of premature death in the United States today, and it is frequently associated with, exacerbates, and is aggravated by chronic kidney disease (CKD). Atherosclerosis integrates the response to a number of insults, and consequently, the accelerated atherosclerosis found in CKD patients is associated with activation of a variety of humoral and tissue mechanisms. Hypertension, diabetes, dyslipidemia, obesity, metabolic syndrome, and additional nontraditional risk factors can damage the kidney directly and by promoting intrarenal atherogenesis, even in the absence of obstructive lesions in the renal artery. Evidence indicates that increased oxidative stress and inflammation may mediate a large part of the effects of risk factors on the kidney. In turn, progressive deterioration of renal function in CKD may lead to dyslipidemia or accumulation of uremic toxins, which can induce production of free radicals and activate proinflammatory and fibrogenic factors, leading to vascular endothelial cell dysfunction and injury, and favoring development of atherosclerosis. Therefore, the kidney can be a villain or a victim during atherogenesis. The purpose of this review is to provide new insights into the mechanisms by which atherogenic factors may instigate early renal injury.

The Future of Renal Support: High-Flux Dialysis to Bioartificial Kidneys

Renal failure continues to cause a major burden of morbidity and mortality in both its acute and chronic forms, regardless of advances in current renal replacement therapies. A bioartificial kidney that includes a conventional dialysis filter and a renal tubule assist device containing approximately 10(8) renal proximal tubule cells was recently successfully engineered. This therapeutic modality may decrease the survival gap between current renal replacement therapies and healthy kidney functions and may lessen the heavy burden of morbidity and mortality associated with renal failure, both acute and chronic, in the near future.

Renal disease in cardiovascular disorders: an underrecognized problem

Chronic renal disease is generally appreciated as a major and rapidly growing health problem. In the United States alone, as many as 19.5 million people may have markers of early renal disease, and more than 660,000 people are expected to require renal replacement therapy by the year 2010. By contrast, the presence and pathological role of renal disease in patients with cardiovascular disease are somewhat underrecognized. Evidence now shows that even minor impairments in renal function, as indicated by measures including glomerular filtration rate and microalbuminuria, are common in cardiovascular disease states and predictive of cardiovascular events. Indeed, microalbuminuria may be a marker of systemic vascular disease rather than kidney dysfunction alone. In patients with hypertension, diabetes, metabolic syndrome, acute coronary syndromes, and stroke, markers of renal disease have proved to be at least as predictive of morbidity and mortality as conventional risk factors. Yet, chart reviews in a variety of clinical settings reflect poor recognition and management of renal disease in at-risk patients. Models for renal protection are based on the control of risk factors, particularly blood pressure, that are associated with renal and cardiovascular outcomes. Screening protocols for markers of renal disease should recognize the potential inaccuracy of serum creatinine concentrations and the preferability of glomerular filtration rate estimates that take age and gender into account. Pilot programs for screening high-risk populations have shown efficacy in detecting renal disease.

The burden of kidney disease: improving global outcomes

Chronic kidney disease (CKD) is a worldwide public health problem. There is an increasing incidence and prevalence of patients with kidney failure requiring replacement therapy, with poor outcomes and high cost. There is an even higher prevalence of patients in earlier stages of CKD, with adverse outcomes such as kidney failure, cardiovascular disease, and premature death. Patients at earlier stages of CKD can be detected through laboratory testing and their treatment is effective in slowing the progression to kidney failure and reducing cardiovascular events. The science and evidence-based care of these patients are universal and independent of their geographic location. There is a clear need to develop a uniform and global public health approach to the worldwide epidemic of CKD. It is to this end that a new initiative "Kidney Disease: Improving Global Outcomes" has been established. Its stated mission is "Improve the care and outcomes of kidney disease patients worldwide through promoting coordination, collaboration and integration of initiatives to develop and implement clinical practice guidelines."

The association between congestive heart failure and chronic renal disease

PURPOSE OF REVIEW

Recent findings on the relationship between congestive heart failure and renal failure are summarized in this review.

RECENT FINDINGS

Congestive heart failure is found in about one-quarter of cases of chronic kidney disease. The most common cause of congestive heart failure is ischemic heart disease. The prevalence of congestive heart failure increases greatly as the patient's renal function deteriorates, and, at end-stage renal disease, can reach 65-70%. There is mounting evidence that chronic kidney disease itself is a major contributor to severe cardiac damage and, conversely, that congestive heart failure is a major cause of progressive chronic kidney disease. Uncontrolled congestive heart failure is often associated with a rapid fall in renal function and adequate control of congestive heart failure can prevent this. The opposite is also true: treatment of chronic kidney disease can prevent congestive heart failure. There is new evidence showing the cardioprotective effect of carvedilol in patients on dialysis, and of simvastatin and eplerenone in patients with congestive heart failure. Use of non-steroidal anti-inflammatory drugs doubles the rate of hospitalization in patients with congestive heart failure. Anemia has been found in one-third to half the cases of congestive heart failure, and may be caused not only by chronic kidney disease but by the congestive heart failure itself. The anemia is associated with worsening cardiac and renal status and often with signs of malnutrition. Control of the anemia and aggressive use of the recommended medication for congestive heart failure may improve the cardiac function, patient function and exercise capacity, stabilize the renal function, reduce hospitalization and improve quality of life. Congestive heart failure, chronic kidney disease and anemia therefore appear to act together in a vicious circle in which each condition causes or exacerbates the other. Both congestive heart failure and anemia are often undertreated. Cooperation between nephrologists and other physicians in the treatment of patients with anemic congestive heart failure may improve the quality of care and the subsequent prognosis for both congestive heart failure and chronic kidney disease.

SUMMARY

Adequate and early detection and aggressive treatment of congestive heart failure and chronic kidney disease and the associated anemia may markedly slow the progression of both diseases.

Developmental approaches to kidney tissue engineering

Recent advances in our understanding of the developmental biology of the kidney, as well as the establishment of novel in vitro model systems, have potential implications for kidney tissue engineering. These advances include delineation of the roles of a number of growth factors in the developmental programs of branching morphogenesis and mesenchymal differentiation, a new understanding of the roles of the extracellular matrix, identification of potential “renal” stem cells, the ex vivo propagation and subsequent recombination of isolated components of the kidney, and successful transplantation of renal primordia into adult hosts. This review will examine these advances in the context of approaches to tissue engineering. Finally, novel approaches that synthesize advances in both cell-based and organ-based approaches are proposed.