Taming the chronic kidney disease epidemic: a global view of surveillance efforts

A national surveillance project on chronic kidney disease management in Canadian primary care: a study protocol

INTRODUCTION

Effective chronic disease care is dependent on well-organised quality improvement (QI) strategies that monitor processes of care and outcomes for optimal care delivery. Although healthcare is provincially/territorially structured in Canada, there are national networks such as the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) as important facilitators for national QI-based studies to improve chronic disease care. The goal of our study is to improve the understanding of how patients with chronic kidney disease (CKD) are managed in primary care and the variation across practices and provinces and territories to drive improvements in care delivery.

METHODS AND ANALYSIS

The CPCSSN database contains anonymised health information from the electronic medical records for patients of participating primary care practices (PCPs) across Canada (n=1200). The dataset includes information on patient sociodemographics, medications, laboratory results and comorbidities. Leveraging validated algorithms, case definitions and guidelines will help define CKD and the related processes of care, and these enable us to: (1) determine prevalent CKD burden; (2) ascertain the current practice pattern on risk identification and management of CKD and (3) study variation in care indicators (eg, achievement of blood pressure and proteinuria targets) and referral pattern for specialist kidney care. The process of care outcomes will be stratified across patients' demographics as well as provider and regional (provincial/territorial) characteristics. The prevalence of CKD stages 3-5 will be presented as age-sex standardised prevalence estimates stratified by province and as weighted averages for population rates with 95% CIs using census data. For each PCP, age-sex standardised prevalence will be calculated and compared with expected standardised prevalence estimates. The process-based outcomes will be defined using established methods.

ETHICS AND DISSEMINATION

The CPCSSN is committed to high ethical standards when dealing with individual data collected, and this work is reviewed and approved by the Network Scientific Committee. The results will be published in peer-reviewed journals and presented at relevant national and international scientific meetings.

CKD.QLD: establishment of a chronic kidney disease [CKD] registry in Queensland, Australia

Background

Chronic kidney disease [CKD] is recognised as a global public health problem. Until recently, the majority of information informing on CKD has been generated from renal registries reporting on patients with end-stage kidney disease [ESKD] and on renal replacement therapy [RRT]. There has been a paucity of information on pre-dialysis CKD cohorts, and many issues related to these poorly described populations are unresolved. To this end, international organizations have called for CKD surveillance systems across all countries.

Description

In Australia, we have responded by developing the Chronic Kidney Disease in Queensland [CKD.QLD] with three main platforms consisting of CKD Registry, clinical trials and development of biobank. This registry which is the core component of CKD surveillance was conceptualized specifically for the pre-dialysis population in the public health system in Queensland, Australia. Recruitment started in May 2011, and to date the Registry has evolved as one of the largest CKD cohorts in the world with recruitment close to 7000 patients. The Registry has had many outcomes, including being the nidus for Australia’s first National Health and Medical Research Council [NHMRC] CKD Centre of Research Excellence [CKD.CRE].

Conclusions

The Registry, with its linkage to Queensland Health datasets, is reporting, and is expected to continue generating, significant information on multiple aspects of CKD, its trajectory, management and patient outcomes. Intent of the CKD.CRE is to facilitate an expanded Registry network that has representation from health services, both public and private, across Australia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0607-5) contains supplementary material, which is available to authorized users.

Comparison between Atorvastatin and Rosuvastatin in Renal Function Decline among Patients with Diabetes

BACKGROUND

Although the beneficial effects of statin treatment in dyslipidemia and atherosclerosis have been well studied, there is limited information regarding the renal effects of statins in diabetic nephropathy. We aimed to investigate whether, and which, statins affected renal function in Asian patients with diabetes.

METHODS

We enrolled 484 patients with diabetes who received statin treatment for more than 12 months. We included patients treated with moderate-intensity dose statin treatment (atorvastatin 10 to 20 mg/day or rosuvastatin 5 to 10 mg/day). The primary outcome was a change in estimated glomerular filtration rate (eGFR) during the 12-month statin treatment, and rapid renal decline was defined as a >3% reduction in eGFR in a 1-year period.

RESULTS

In both statin treatment groups, patients showed improved serum lipid levels and significantly reduced eGFRs (from 80.3 to 78.8 mL/min/1.73 m² for atorvastatin [P=0.012], from 79.1 to 76.1 mL/min/1.73 m² for rosuvastatin [P=0.001]). A more rapid eGFR decline was observed in the rosuvastatin group than in the atorvastatin group (48.7% vs. 38.6%, P=0.029). Multiple logistic regression analyses demonstrated more rapid renal function loss in the rosuvastatin group than in the atorvastatin group after adjustment for other confounding factors (odds ratio, 1.60; 95% confidence interval, 1.06 to 2.42).

CONCLUSION

These results suggest that a moderate-intensity dose of atorvastatin has fewer detrimental effects on renal function than that of rosuvastatin.

Assessment of Global Kidney Health Care Status

IMPORTANCE

Kidney disease is a substantial worldwide clinical and public health problem, but information about available care is limited.

OBJECTIVE

To collect information on the current state of readiness, capacity, and competence for the delivery of kidney care across countries and regions of the world.

DESIGN, SETTING, AND PARTICIPANTS

Questionnaire survey administered from May to September 2016 by the International Society of Nephrology (ISN) to 130 ISN-affiliated countries with sampling of key stakeholders (national nephrology society leadership, policy makers, and patient organization representatives) identified by the country and regional nephrology leadership through the ISN.

MAIN OUTCOMES AND MEASURES

Core areas of country capacity and response for kidney care.

RESULTS

Responses were received from 125 of 130 countries (96%), including 289 of 337 individuals (85.8%, with a median of 2 respondents [interquartile range, 1-3]), representing an estimated 93% (6.8 billion) of the world's population of 7.3 billion. There was wide variation in country readiness, capacity, and response in terms of service delivery, financing, workforce, information systems, and leadership and governance. Overall, 119 (95%), 95 (76%), and 94 (75%) countries had facilities for hemodialysis, peritoneal dialysis, and kidney transplantation, respectively. In contrast, 33 (94%), 16 (45%), and 12 (34%) countries in Africa had facilities for hemodialysis, peritoneal dialysis, and kidney transplantation, respectively. For chronic kidney disease (CKD) monitoring in primary care, serum creatinine with estimated glomerular filtration rate and proteinuria measurements were reported as always available in only 21 (18%) and 9 (8%) countries, respectively. Hemodialysis, peritoneal dialysis, and transplantation services were funded publicly and free at the point of care delivery in 50 (42%), 48 (51%), and 46 (49%) countries, respectively. The number of nephrologists was variable and was low (<10 per million population) in Africa, the Middle East, South Asia, and Oceania and South East Asia (OSEA) regions. Health information system (renal registry) availability was limited, particularly for acute kidney injury (8 countries [7%]) and nondialysis CKD (9 countries [8%]). International acute kidney injury and CKD guidelines were reportedly accessible in 52 (45%) and 62 (52%) countries, respectively. There was relatively low capacity for clinical studies in developing nations.

CONCLUSIONS AND RELEVANCE

This survey demonstrated significant interregional and intraregional variability in the current capacity for kidney care across the world, including important gaps in services and workforce. Assuming the responses accurately reflect the status of kidney care in the respondent countries, the findings may be useful to inform efforts to improve the quality of kidney care worldwide.

Seroprevalence of a "new" bacterium, Simkania negevensis, in renal transplant recipients and in hemodialysis patients

Background

Simkania negevensis is an obligate intracellular bacterium belonging to the family Simkaniaceae in the Chlamydiales order. It is considered an ubiquitous microorganism and aquatic environments may be involved as a source of infection for humans. It was just isolated in samples from domestic water supplies and from mains water supplies, like spa water or swimming pool water, confirming its ability to resist to the common chlorination treatments. Evidence indicates a possible role of the microorganism in respiratory tract infections, in gastroenteric disorders and in the pathogenesis of cardiovascular disease, furthermore it has hypothesized that it could play a role in lung transplant rejection. Prevalence and possible effects in nephrology are unknown.

Methods

We examined the occurrence of Simkania negevensis in two differents populations, both characterized by a high susceptibility to infectious complications: 105 hemodialysis patients, 105 renal transplant recipients and 105 healthy subjects through the IgG and IgA response to Simkania negevensis in their sera. Serum antibodies to Simkania negevensis were detected by a homemade ELISA performed according to the Kahane’s protocol. Furthermore water samples from hemodialytic circuit were collected, to evaluate Simkania negevensis resistance to usual treatment of disinfection.

Results

Our results were unexpected, showing a higher seroprevalence of antibodies against Simkania negevensis in the hemodialysis patients, compared to renal transplant patients (IgG 22% vs 9% - IgA 9% vs 3%). S. negevensis was isolated in all water samples analyzed.

Conclusions

Our study detected for the first time the occurrence of S. negevensis in hemodialysis and in renal transplant patients. Our findings suggest that water used in hemodialysis could be one of the possible sources of S. negevensis infection, without clinical involvement risk for patients.

Decreased incidence of end-stage renal disease in American Indians with diabetes: a model for other high-risk populations?

Indigenous populations in North America have very high rates of diabetes and diabetic complications, including end-stage renal disease. A promising new report demonstrates a substantial decline in the incidence of diabetic end-stage renal disease among American Indians and Alaska Natives, coinciding with a public health intervention targeting diabetes management in this population. This success may offer a model for interventions to improve kidney disease outcomes in other high-risk populations.

An expanded nationwide view of chronic kidney disease in Aboriginal Australians

We summarize new knowledge that has accrued in recent years on chronic kidney disease (CKD) in Indigenous Australians. CKD refers to all stages of preterminal kidney disease, including end‐stage kidney failure (ESKF), whether or not a person receives renal replacement therapy (RRT). Recently recorded rates of ESKF, RRT, non‐dialysis CKD hospitalizations and CKD attributed deaths were, respectively, more than sixfold, eightfold, eightfold and threefold those of non‐Indigenous Australians, with age adjustment, although all except the RRT rates are still under‐enumerated. However, the nationwide average Indigenous incidence rate of RRT appears to have stabilized. The median age of Indigenous people with ESKF was about 30 years less than for non‐Indigenous people, and 84% of them received RTT, while only half of non‐Indigenous people with ESKF did so. The first‐ever (2012) nationwide health survey data showed elevated levels of CKD markers in Indigenous people at the community level. For all CKD parameters, rates among Indigenous people themselves were strikingly correlated with increasing remoteness of residence and socio‐economic disadvantage, and there was a female predominance in remote areas. The burden of renal disease in Australian Indigenous people is seriously understated by Global Burden of Disease Mortality methodology, because it employs underlying cause of death only, and because deaths of people on RRT are frequently attributed to non‐renal causes.

These data give a much expanded view of CKD in Aboriginal people. Methodologic approaches must be remedied for a full appreciation of the burden, costs and outcomes of the disease, to direct appropriate policy development.

Excellent review on the kidney health in the Aboriginal communities in Australia, describing the challenges and important priorities.

A systematic review and meta-analysis suggests obesity predicts onset of chronic kidney disease in the general population

Obesity and chronic kidney disease (CKD) are public health priorities that share core pathophysiological mechanisms. However, whether high body mass index (BMI) increases risk of CKD de novo remains ill-defined. To evaluate the role of BMI in predicting CKD onset in the general adult population, we performed a systematic review and meta-analysis of PubMed and ISI Web of Science databases articles published between January 2000 and August 2016 without language restriction. We selected studies in adult individuals from a general population with normal renal function at baseline that reported the risk of low estimated glomerular filtration (eGFR) (under 60 mL/min/1.73m²) and/or albuminuria (1+ at dipstick or an albumin creatinine ratio of 3.4 mg/mmol or more) as hazard ratio, odds ratio or relative risk related to obesity, overweight, or BMI as continuous value. A total of 39 cohorts covering 630, 677 participants with a mean follow-up of 6.8 years were selected. Obesity increased the relative risk, 95% confidence interval and heterogeneity (I²) of developing low eGFR (1.28, 1.07-1.54, [I²: 95.0%]) and albuminuria (1.51, 1.36-1.67, [I²: 62.7%]). Increase of BMI unit was also associated with higher risk of low eGFR (1.02, 1.01-1.03, [I²: 24.3%]) and albuminuria (1.02, 1.00-1.04, [I²: 0%]). Conversely, overweight did not predict onset of either low eGFR (1.06, 0.94-1.21, [I²: 50.0%]) or albuminuria (1.24, 0.98-1.58, [I²: 49.4%]). Thus, a high BMI predicts onset of albuminuria without kidney failure (CKD stages 1-2) as well as CKD stages 3 and higher, the effect being significant only in obese individuals. Hence, our findings may have implications to improve risk stratification and recommendations on body weight control in the general population.

Chronic kidney disease: identification and management in primary care

Chronic kidney disease (CKD) is an important and common noncommunicable condition globally. In national and international guidelines, CKD is defined and staged according to measures of kidney function that allow for a degree of risk stratification using commonly available markers. It is often asymptomatic in its early stages, and early detection is important to reduce future risk. The risk of cardiovascular outcomes is greater than the risk of progression to end-stage kidney disease for most people with CKD. CKD also predisposes to acute kidney injury - a major cause of morbidity and mortality worldwide. Although only a small proportion of people with CKD progress to end-stage kidney disease, renal replacement therapy (dialysis or transplantation) represents major costs for health care systems and burden for patients. Efforts in primary care to reduce the risks of cardiovascular disease, acute kidney injury, and progression are therefore required. Monitoring renal function is an important task, and primary care clinicians are well placed to oversee this aspect of care along with the management of modifiable risk factors, particularly blood pressure and proteinuria. Good primary care judgment is also essential in making decisions about referral for specialist nephrology opinion. As CKD commonly occurs alongside other conditions, consideration of comorbidities and patient wishes is important, and primary care clinicians have a key role in coordinating care while adopting a holistic, patient-centered approach and providing continuity. This review aims to summarize the vital role that primary care plays in predialysis CKD care and to outline the main considerations in its identification, monitoring, and clinical management in this context.

An external validation of models to predict the onset of chronic kidney disease using population-based electronic health records from Salford, UK

BACKGROUND

Chronic kidney disease (CKD) is a major and increasing constituent of disease burdens worldwide. Early identification of patients at increased risk of developing CKD can guide interventions to slow disease progression, initiate timely referral to appropriate kidney care services, and support targeting of care resources. Risk prediction models can extend laboratory-based CKD screening to earlier stages of disease; however, to date, only a few of them have been externally validated or directly compared outside development populations. Our objective was to validate published CKD prediction models applicable in primary care.

METHODS

We synthesised two recent systematic reviews of CKD risk prediction models and externally validated selected models for a 5-year horizon of disease onset. We used linked, anonymised, structured (coded) primary and secondary care data from patients resident in Salford (population ~234 k), UK. All adult patients with at least one record in 2009 were followed-up until the end of 2014, death, or CKD onset (n = 178,399). CKD onset was defined as repeated impaired eGFR measures over a period of at least 3 months, or physician diagnosis of CKD Stage 3-5. For each model, we assessed discrimination, calibration, and decision curve analysis.

RESULTS

Seven relevant CKD risk prediction models were identified. Five models also had an associated simplified scoring system. All models discriminated well between patients developing CKD or not, with c-statistics around 0.90. Most of the models were poorly calibrated to our population, substantially over-predicting risk. The two models that did not require recalibration were also the ones that had the best performance in the decision curve analysis.

CONCLUSIONS

Included CKD prediction models showed good discriminative ability but over-predicted the actual 5-year CKD risk in English primary care patients. QKidney, the only UK-developed model, outperformed the others. Clinical prediction models should be (re)calibrated for their intended uses.

Long-term trends in the prevalence of chronic kidney disease and the influence of cardiovascular risk factors in Norway

Surveillance of chronic kidney disease (CKD) prevalence over time and information on how changing risk factors influence this trend are needed to evaluate the effects of general practice and public health interventions. Because very few studies addressed this, we studied the total adult population of a demographically stable county representative of Norway using cross-sectional studies 10 years apart (Nord-Trøndelag Health Study (HUNT)2 and Nord-Trøndelag Health Study (HUNT)3, 65,237 and 50,586 participants, respectively). Thorough quality-control procedures and comparisons of methods over time excluded analytical drift, and multiple imputations of missing data combined with nonattendance weights contributed to unbiased estimates. CKD prevalence remained stable in Norway from 1995 through 1997 (11.3%) to 2006 through 2008 (11.1%). The association of survey period with CKD prevalence was modified by a strong decrease in blood pressure, more physical activity, and lower cholesterol levels. Without these improvements, a 2.8, 0.7, and 0.6 percentage points higher CKD prevalence could have been expected, respectively. In contrast, the prevalence of diabetes and obesity increased moderately, but the proportion of diabetic patients with CKD decreased significantly (from 33.4% to 28.6%). A CKD prevalence of 1 percentage point lower would have been expected without these changes. Thus, CKD prevalence remained stable in Norway for more than a decade in association with marked improvements in blood pressure, lipid levels, and physical activity and despite modest increases in diabetes and obesity.

Atg5-mediated autophagy deficiency in proximal tubules promotes cell cycle G2/M arrest and renal fibrosis

Macroautophagy/autophagy protects against cellular stress. Renal sublethal injury-triggered tubular epithelial cell cycle arrest at G2/M is associated with interstitial fibrosis. However, the role of autophagy in renal fibrosis is elusive. Here, we hypothesized that autophagy activity in tubular epithelial cells is pivotal for inhibition of cell cycle G2/M arrest and subsequent fibrogenic response. In both renal epithelial cells stimulated by angiotensin II (AGT II) and the murine kidney after unilateral ureteral obstruction (UUO), we observed that occurrence of autophagy preceded increased production of COL1 (collagen, type I). Pharmacological enhancement of autophagy by rapamycin suppressed COL1 accumulation and renal fibrosis. In contrast, genetic ablation of autophagy by proximal tubular epithelial cell-specific deletion of Atg5, with reduction of the LC3-II protein level and degradation of SQSTM1/p62, showed marked cell cycle arrest at the G2/M phase, robust COL1 deposition, and severe interstitial fibrosis in a UUO model, as compared with wild-type mice. In vitro, AGT II exposure triggered autophagy preferentially in the G1/S phase, and increased COL1 expression in the G2/M phase in renal epithelial cells. Stimulation of Atg5-deficient primary proximal tubular cells with AGT II also resulted in elevated G2/M arrest and COL1 production. Pharmacological or genetic inhibition of autophagy increased AGT II-mediated G2/M arrest. Enhanced expression of ATG5, but not the autophagy-deficient ATG5 mutant K130R, rescued the G2/M arrest, suggesting the regulation of cell cycle progression by ATG5 is autophagy dependent. In conclusion, Atg5-mediated autophagy in proximal epithelial cells is a critical host-defense mechanism that prevents renal fibrosis by blocking G2/M arrest.

Risk prediction to inform surveillance of chronic kidney disease in the US Healthcare Safety Net: a cohort study

Background

The capacity of electronic health record (EHR) data to guide targeted surveillance in chronic kidney disease (CKD) is unclear. We sought to leverage EHR data for predicting risk of progressing from CKD to end-stage renal disease (ESRD) to help inform surveillance of CKD among vulnerable patients from the healthcare safety-net.

Methods

We conducted a retrospective cohort study of adults (n = 28,779) with CKD who received care within 2 regional safety-net health systems during 1996–2009 in the Western United States. The primary outcomes were progression to ESRD and death as ascertained by linkage with United States Renal Data System and Social Security Administration Death Master files, respectively, through September 29, 2011. We evaluated the performance of 3 models which included demographic, comorbidity and laboratory data to predict progression of CKD to ESRD in conditions commonly targeted for disease management (hypertension, diabetes, chronic viral diseases and severe CKD) using traditional discriminatory criteria (AUC) and recent criteria intended to guide population health management strategies.

Results

Overall, 1730 persons progressed to end-stage renal disease and 7628 died during median follow-up of 6.6 years. Performance of risk models incorporating common EHR variables was highest in hypertension, intermediate in diabetes and chronic viral diseases, and lowest in severe CKD. Surveillance of persons who were in the highest quintile of ESRD risk yielded 83–94 %, 74–95 %, and 75–82 % of cases who progressed to ESRD among patients with hypertension, diabetes and chronic viral diseases, respectively. Similar surveillance yielded 42–71 % of ESRD cases among those with severe CKD. Discrimination in all conditions was universally high (AUC ≥0.80) when evaluated using traditional criteria.

Conclusions

Recently proposed discriminatory criteria account for varying risk distribution and when applied to common clinical conditions may help to inform surveillance of CKD in diverse populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0272-0) contains supplementary material, which is available to authorized users.

Psychometric Evaluation of the Vietnamese Hemodialysis Stressor Scale

The lack of a suitable assessment tool may limit optimal stress management and impair the health-related quality of life of patients undergoing hemodialysis. The purpose of the study was to examine latent constructs and psychometric properties of the Vietnamese Hemodialysis Stressor Scale (HSS-V). In total, 180 patients receiving hemodialysis were recruited. Psychometric properties of the HSS-V, including the construct validity, internal consistency, and test-retest reliability, were tested after the instrument translation. The exploratory factor analysis resulted in a 24-item HSS-V with four extracted factors, which explained 58.32% of the total variance. The construct validity was confirmed by significant negative correlations between scores on the HSS-V and Vietnamese-version Short Form-36. The internal consistency (Cronbach's α = .82-.91) and test-retest reliability (intra-class correlations coefficient = .91-.94) of the 24-item HSS-V were satisfactory. A simple structure and preliminary acceptable psychometric properties of the HSS-V were established and can serve as a basis for further studies.

A randomized controlled trial protocol testing a decision support intervention for older patients with advanced kidney disease

AIM

To assess the effectiveness of a decision support intervention using a pragmatic single blind Randomized Controlled Trial.

BACKGROUND

Worldwide the proportion of older people (aged 65 years and over) is rising. This population is known to have a higher prevalence of chronic diseases including chronic kidney disease. The resultant effect of the changing health landscape is seen in the increase in older patients (aged ≥65 years) commencing on dialysis. Emerging evidence suggests that for some older patients dialysis may provide minimal benefit. In a majority of renal units non-dialysis management is offered as an alternative to undertaking dialysis. Research regarding decision-making support that is required to assist this population in choosing between dialysis or non-dialysis management is limited.

DESIGN

A multisite single blinded pragmatic randomized controlled trial is proposed.

METHODS

Patients will be recruited from four Queensland public hospitals and randomizd into either the control or intervention group. The decision support intervention is multimodal and includes counselling provided by a trained nurse. The comparator is standard decision-making support. The primary outcomes are decisional regret and decisional conflict. Secondary outcomes are improved knowledge and quality of life. Ethics approval obtained November 2014.

CONCLUSION

This is one of the first randomized controlled trials assessing a decision support intervention in older people with advance chronic kidney disease. The results may provide guidance for clinicians in future approaches to assist this population in decision-making to ensure reduced decisional regret and decisional conflict.

Endoplasmic reticulum stress drives proteinuria-induced kidney lesions via Lipocalin 2

In chronic kidney disease (CKD), proteinuria results in severe tubulointerstitial lesions, which ultimately lead to end-stage renal disease. Here we identify 4-phenylbutyric acid (PBA), a chemical chaperone already used in humans, as a novel therapeutic strategy capable to counteract the toxic effect of proteinuria. Mechanistically, we show that albumin induces tubular unfolded protein response via cytosolic calcium rise, which leads to tubular apoptosis by Lipocalin 2 (LCN2) modulation through ATF4. Consistent with the key role of LCN2 in CKD progression, Lcn2 gene inactivation decreases ER stress-induced apoptosis, tubulointerstitial lesions and mortality in proteinuric mice. More importantly, the inhibition of this pathway by PBA protects kidneys from morphological and functional degradation in proteinuric mice. These results are relevant to human CKD, as LCN2 is increased in proteinuric patients. In conclusion, our study identifies a therapeutic strategy susceptible to improve the benefit of RAS inhibitors in proteinuria-induced CKD progression.

Methods Used in Economic Evaluations of Chronic Kidney Disease Testing - A Systematic Review

Background

The prevalence of chronic kidney disease (CKD) is high in general populations around the world. Targeted testing and screening for CKD are often conducted to help identify individuals that may benefit from treatment to ameliorate or prevent their disease progression.

Aims

This systematic review examines the methods used in economic evaluations of testing and screening in CKD, with a particular focus on whether test accuracy has been considered, and how analysis has incorporated issues that may be important to the patient, such as the impact of testing on quality of life and the costs they incur.

Methods

Articles that described model-based economic evaluations of patient testing interventions focused on CKD were identified through the searching of electronic databases and the hand searching of the bibliographies of the included studies.

Results

The initial electronic searches identified 2,671 papers of which 21 were included in the final review. Eighteen studies focused on proteinuria, three evaluated glomerular filtration rate testing and one included both tests. The full impact of inaccurate test results was frequently not considered in economic evaluations in this setting as a societal perspective was rarely adopted. The impact of false positive tests on patients in terms of the costs incurred in re-attending for repeat testing, and the anxiety associated with a positive test was almost always overlooked. In one study where the impact of a false positive test on patient quality of life was examined in sensitivity analysis, it had a significant impact on the conclusions drawn from the model.

Conclusion

Future economic evaluations of kidney function testing should examine testing and monitoring pathways from the perspective of patients, to ensure that issues that are important to patients, such as the possibility of inaccurate test results, are properly considered in the analysis.

Stabilization of Urinary MicroRNAs by Association with Exosomes and Argonaute 2 Protein

A pressing need for new chronic kidney disease (CKD) biomarkers persists. MicroRNAs (miRNAs) are emerging as a novel class of disease biomarkers in body fluids, but mechanisms conferring their stability in urine have not been fully elucidated. Here we investigated stabilization in human urine of ubiquitously expressed miR-16, and miR-192, which we have shown previously to be downregulated in renal fibrosis, by association with extracellular vesicles and with argonaute protein (AGO) 2. Endogenous urinary miR-16 was significantly more resistant to RNase-mediated degradation than exogenous, spiked-in, Caenorhabditis elegans cel-miR-39. We used our previously optimized high-resolution exosome isolation protocol with sucrose gradient ultracentrifugation to sub-fractionate the primary extracellular vesicle-rich urinary pellet. MiR-16 and miR-192 were enriched in exosomal sucrose gradient fractions, but were also detected in all other fractions. This suggested association of urinary miRNAs with other urinary extracellular vesicles and/or pellet components, complicating previous estimates of miRNA:exosome stoichiometry. Proteinase K digestion destabilized urinary miR-16 and we showed, for the first time, RNA-immunoprecipitation of urinary miR-16:AGO2 and miR-192:AGO2 complexes. Association with exosomes and AGO2 stabilized urinary miR-16 and miR-192, suggesting quantitative urinary miRNA analysis has the potential to identify novel, non-invasive CKD biomarkers.

Endoscopic submucosal dissection in early gastric cancer in elderly patients and comorbid conditions

The prognosis of early gastric cancer (EGC) is good if there is no concomitant lymph node metastasis. Therefore, the early detection of EGC is important to improve the prognosis of patients with gastric cancer. In Japan, 40% to 50% of all gastric cancers are EGC, and endoscopic submucosal dissection (ESD) is widely accepted as a local treatment for these lesions, particularly for large lesions that at one time were an indication for gastrectomy because of the difficulty of en-bloc resection. Consequently, this procedure can preserve the entire stomach and the patient’s postoperative quality of life. ESD has become a general technique with improved procedures and devices, and has become the preferred treatment for EGC rather than gastrectomy. Therefore, ESD may demonstrate many advantages in patients who have several comorbidities, particularly elderly population, patients taking antithrombotic agents, or patients with chronic kidney disease, or liver cirrhosis. However, it is not yet clear whether patients with both EGC and comorbidities are feasible candidates for ESD and whether they would consequently be able to achieve a survival benefit after ESD. In this review, we discuss the clinical problems of ESD in patients with EGC and those comorbid conditions.

Selenium and selenium-dependent antioxidants in chronic kidney disease

Oxidative stress plays a key role in numerous disease processes including chronic kidney disease (CKD). In general, oxygen metabolism leads to the formation of reactive oxygen species (ROS) dangerous to cells. Although enzymes and low-molecular-weight antioxidants protect against ROS, chronic imbalances of formation and elimination can eventually overwhelm endogenous defenses leading to deleterious consequences. In CKD, glutathione peroxidases (GSH-Px) play an important role in ROS metabolism. Plasma GSH-Px is synthesized in the kidney and requires selenium (Se) as a cofactor. Interestingly, Se and plasma GSH-Px are both significantly reduced in CKD, especially for those patients on hemodialysis. Supplementation of Se in these patients results in modest increases of GSH-Px, presumably from residual renal tissue. Kidney transplantation rapidly restores plasma GSH-Px. In this chapter, the relevance of these findings to CKD is explored with emphasis on renal disease processes and impact on attendant disorders including cancer and cardiovascular disease.

Prevalence and cardiovascular risk profile of chronic kidney disease in Italy: results of the 2008-12 National Health Examination Survey

BACKGROUND

National surveys in countries outside Europe have reported a high prevalence (11-13%) of chronic kidney disease (CKD). Studies in Europe have provided a variable prevalence likely due to differences in study design, including age and extent of geographic areas, equation used to evaluate estimated glomerular filtration rate (eGFR) and CKD stages examined.

METHODS

The 2008-12 National Health Examination Survey in Italy randomly extracted samples from the general population aged 35-79 years, stratified by age and gender, from the resident list of each Italian region (440 persons/1.5 million of residents). We estimated the prevalence of CKD by means of urinary albumin : creatinine ratio and eGFR (CKD-EPI equation-enzymatic assay of serum creatinine). Cardiovascular (CV) risk profile was also evaluated.

RESULTS

Three thousand eight hundred and forty-eight men and 3704 women were examined. In the whole population, mean age was 57 ± 12 and 56 ± 12 years in men and women, respectively; hypertension was prevalent in men and women, respectively (56 and 43%) and the same held true for overweight (48 and 33%), obesity (26 and 27%), diabetes (14 and 9%) and smoking (21 and 18%), whereas CV disease was less frequent (9 and 6%). Overall, the prevalence of CKD (95% confidence interval) was 7.05% (6.48-7.65). Early stages constituted 59% of the CKD population [Stage G1-2 A2-3: 4.16% (3.71-4.61) and Stage G3-5: 2.89% (2.51-3.26)]. At multivariate regression analysis, age, obesity, hypertension, diabetes, CV disease and smoking were all independent correlates of CKD.

CONCLUSIONS

CKD has a relatively lower prevalence in Italy, in particular for advanced stages, when compared with similar national surveys outside Europe. This occurs despite older age and unfavourable CV risk profile of the whole population.