Canadian Society of Nephrology Commentary on the KDIGO Clinical Practice Guideline for CKD Evaluation and Management

Investigation on the association between Osteopontin and Apolipoprotein E gene polymorphisms and vancomycin-induced acute kidney injury: A pharmacokinetic/pharmacogenetic study in critically ill patients

Vancomycin is a commonly administered antibiotic for various Gram-positive infections in critically ill patients. Vancomycin has a narrow therapeutic index and its main adverse drug reaction is acute kidney injury (AKI). In this regard, various pharmacokinetic parameters have been widely considered for therapeutic drug monitoring (TDM) purposes. Higher vancomycin trough concentration and area under the curve (AUC) values would be associated with higher rates of AKI. Therefore, dose adjustment based on targeted pharmacokinetic values would be essential to avoid toxicity and achieve optimal clinical response. However, there are numerous reports regarding the discrepancy between pharmacokinetic parameter values and AKI. In this regard, we examined the possible role of pharmacogenetics in vancomycin-induced AKI to distinguish patients who are genetically prone to AKI. In this cross-sectional study, polymorphisms of osteopontin (OPN) and Apolipoprotein E (APOE) along with pharmacokinetic parameters were assessed in 87 critically ill patients admitted to ICU wards and received vancomycin. The results indicated a significant difference in OPN and APOE genotype distribution between AKI and non-AKI patients (P = 0.001 and 0.02, respectively). Stepwise multivariate logistic regression analysis showed that patients with e2e3 genotype were 4.2-fold more prone to AKI (P = 0.029; OR = 4.2; 95 %CI = 1.2-15.7). Moreover, there was a significant correlation between pharmacokinetic parameters (calculated trough concentration, AUCτ, AUC24h, and t1/2) and vancomycin-induced AKI. Genotyping the patients for OPN and APOE polymorphisms before vancomycin initiation would be promising as a routine clinical practice to obtain an efficient clinical response and prevent vancomycin-induced AKI, especially in critically ill patients.

From Liver to Kidney: The Overlooked Burden of Nonalcoholic Fatty Liver Disease in Chronic Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is increasingly recognized as a contributor to chronic kidney disease (CKD), yet its impact remains underappreciated in clinical practice. Recent studies reveal a strong association between NAFLD and CKD progression, with evidence linking hepatic dysfunction to renal impairment through metabolic and inflammatory pathways. NAFLD not only increases the risk of CKD but also accelerates its progression, leading to worse cardiovascular outcomes and higher mortality, particularly in patients with advanced fibrosis. Despite this growing evidence, NAFLD often goes undiagnosed in CKD patients and routine hepatic evaluation is rarely integrated into nephrology care. Emerging diagnostic tools, including noninvasive biomarkers and imaging techniques, offer potential for earlier detection, yet their clinical implementation remains inconsistent. Although lifestyle modifications remain the foundation of treatment, pharmacotherapeutic strategies, including SGLT2 inhibitors and GLP-1 receptor agonists, have demonstrated potential in mitigating both hepatic and renal impairment. Recognizing the interplay between NAFLD and CKD is essential for improving patient outcomes. A multidisciplinary approach, integrating hepatology and nephrology expertise, is crucial to refining screening strategies, optimizing treatment, and reducing the long-term burden of these coexisting conditions.

Use of the BIOGROUP® French laboratories database to conduct CKD observational studies: a pilot EPI-CKD1 study

OBJECTIVES

Medical biology is essential for diagnosing and monitoring cardio-reno-metabolic diseases. The EPI-CKD1 study utilizes data from Biogroup® French laboratories to examine the burden of chronic kidney disease (CKD) and the effect of heart failure, and diabetes in an outpatient setting in order to address gaps in national databases that lack biological data.

METHODS

All adults (≥18 years) with at least one blood creatinine test between January 1st of 2021, and June 30th of 2022 were included. Key biomarkers measured included serum creatinine, estimated glomerular filtration rate (eGFR), hemoglobin A1c, B-type natriuretic peptide (BNP), NT-Pro BNP, and urinary albumin/creatinine ratio (uACR).

RESULTS

Among a total of 4,061,208 adults with at least one blood creatinine test, 465,225 (11.5 %) had altered kidney function. Their mean age was 57.9 years (SD 18.8), with 56.7 % women. Diabetes was present in 8.3 %, and heart failure in 1.4 %. Altered kidney function standardized prevalence was estimated to 8.06 %, with an incidence of 5.10 %. Patients with end-stage CKD had an average of 7.9 eGFR measurements, compared to 2 for those with eGFR >60 mL/min/1.73 m2. Older age, diabetes, and heart failure were associated with an increased risk of eGFR <60 mL/min/1.73 m2.

CONCLUSIONS

The EPI-CKD1 study demonstrates the utility of Biogroup® data for large-scale observational studies, offering precise, medically relevant insights on patients at cardio-renal risk. Future studies should focus on data enrichment and long-term follow-up to deepen understanding.

Investigating the association of albuminuria with the incidence of preeclampsia and its predictive capabilities: a systematic review and meta-analysis

BACKGROUND

Preeclampsia (PE) is a severe hypertensive disorder affecting approximately 6.7% of pregnancies worldwide. Identifying reliable biomarkers for early prediction could significantly reduce the incidence of PE and facilitate closer monitoring and timely management. This study aims to investigate the association between albuminuria in early pregnancy and the subsequent development of PE, and to explore its predictive abilities.

METHODS

A systematic search was conducted across PubMed, Embase, and Web of Science on July 15, 2024, for studies published between January 1, 1990, and June 30, 2024. Quality assessments were performed using the Joanna Briggs Institute Critical Appraisal and Risk of Bias in Non-randomized Studies - of Exposures Checklists. Random-effects models in STATA were used to conduct meta-analyses comparing urine albumin and albumin-to-creatinine ratio levels in patients who later developed PE versus those who did not. The incidence of PE was also compared between patients with and without albuminuria in early pregnancy. The predictive ability of albuminuria for PE was assessed using META-DISC software.

RESULTS

A total of 26 studies comprising 7,640 pregnant women were systematically reviewed. Of these, 17 studies met the quality criteria for inclusion in the meta-analyses. Our findings indicate that urine albumin (Hedges's g = 0.48 [95% confidence interval (CI): 0.16-0.80]; p-value < 0.001) and albumin-to-creatinine ratio (Hedges's g = 0.48 [95% CI: 0.16-0.80]; p-value = 0.003) were significantly higher in the early stages of pregnancy in patients who later developed PE compared to those who did not. The incidence of PE was higher in patients with early-diagnosed albuminuria (log odds ratio = 2.56 [95% CI: 1.75-3.38]; p-value < 0.001). The pooled sensitivity and specificity for albuminuria in predicting PE were 56% [95% CI: 48-64%] and 87% [95% CI: 85-89%], respectively.

CONCLUSIONS

Elevated maternal urine albumin and albumin-to-creatinine ratio in early pregnancy are associated with a higher risk of developing PE. While these biomarkers show promise for early identification of at-risk patients, the relatively low sensitivity suggests that albuminuria alone may not be a robust predictor of PE, which underscores the need for future research in this regard.

TRIAL REGISTRATION

Review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under the code CRD42024575772.

Chronic kidney disease among people living with HIV on TDF based regimen: A systematic review and meta-analysis

INTRODUCTION

Chronic kidney disease is a major public health concern among people living with human immunodeficiency virus (PLWHIV) who are taking tenofovir disoproxil fumarate-based regimen. Despite the available evidence showing a high prevalence of CKD in this population, comprehensive pooled estimate of CKD among PLWHIV receiving TDF based regimen across the globe is lacking. Hence, the present systematic review aimed to provide a global pooled prevalence estimate of CKD.

METHOD

We conducted a systematic review of literatures published between January 2000 and May 2024. Articles and grey literature were searched from the following databases and search engine: PubMed, EMBASE, Scopus, Web of science, The Cumulative Index to Nursing and Allied Health Literature (CINHAL), and Google Scholar. We included eligible studies that report magnitude of CKD in TDF based regimen. We executed the pooled CKD, subgroup analysis, and funnel plot using random effect model. All statistical analysis including sensitivity analysis were made using Stata 17 software.

RESULTS

Sixty-nine studies with 88299 participants included in this meta-analysis. The pooled prevalence of CKD was 7% (95% CI:6-8). CD4 count less than 200 copies per milliliter, and being female were associated with CKD.

CONCLUSION

We concluded that the magnitude of CKD across the globe is high in people living with HIV who have received TDF based regimen. Early identification of CKD by considering regular renal function monitoring, and risk factors especially low CD4 count, and female gender at birth are essential.

TRIAL REGISTRATION

The protocol has been prospectively registered with PROSPERO ((CRD42020136813).

Augmenter of liver regeneration inhibits renal fibrosis during acute kidney injury to chronic kidney disease transition by regulating autophagic flux

BACKGROUND

Augmenter of liver regeneration (ALR) is believed to protect against acute kidney injury (AKI). The objective of this study was to investigate the mechanisms of ALR in the transition from AKI to chronic kidney disease (CKD).

METHODS

ALR Conditional Knockout (CKO) mice were bilateral renal artery clamped to induce AKI and CKD. Serum creatinine, blood urea nitrogen, and uric acid were measured to reflect renal function. Renal histology was used to assess kidney damage. Transcriptome sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to identify differentially expressed genes (DEGs) and related pathways. TUNEL assay was conducted to assess apoptosis. Polymerase chain reaction and immunohistology were used to analyze autophagy-related factors and kidney fibrosis. AAV9-mRFP-GFP-LC3 was injected to observe autophagy flux.

RESULTS

In the murine models of AKI and CKD, loss of ALR led to markedly reduced renal function and renal tubular pathology injury. Multiple autophagy-related pathways were found to be enriched in up-regulated DEGs in transcriptome sequencing of ALR CKO and control groups with AKI. Renal fibrosis was evident in ALR CKO mice, with marked suppression of Beclin-1, a factor associated with the initiation phase of autophagy, and ATG5, an important factor in the extension phase of autophagosomes. The marked accumulation of LC3 and SQSTM1/P62, which is associated with the formation of autophagosomes, was also observed, suggesting an impairment of autophagic processes. Correspondingly, the AAV9-mRFP-GFP-LC3 results indicated that decreased ALR led to the accumulation of autophagosomes and impaired autophagic lysosome generation.

CONCLUSIONS

Collectively, these results suggested that ALR deficiency led to apoptosis and enhanced renal fibrosis by impairing autophagic flux, which in turn led to the transition of AKI to CKD.

Prevention of Transition from Acute Kidney Injury to Chronic Kidney Disease Using Clinical-Grade Perinatal Stem Cells in Non-Clinical Study

Acute kidney injury (AKI) is widely recognized as a precursor to the onset or rapid progression of chronic kidney disease (CKD). However, there is currently no effective treatment available for AKI, underscoring the urgent need for the development of new strategies to improve kidney function. Human placental mesenchymal stromal cells (hpMSCs) were isolated from donor placentas, cultured, and characterized with regard to yield, viability, flow cytometry, and potency. To mimic AKI and its progression to CKD in a rat model, a dedicated sensitive non-clinical bilateral kidney ischemia-reperfusion injury (IRI) model was utilized. The experimental group received 3 × 105 hpMSCs into each kidney, while the control group received IRI and saline and the untreated group received IRI only. Urine, serum, and kidney tissue samples were collected over a period of 28 days. The hpMSCs exhibited consistent yields, viability, and expression of mesenchymal lineage markers, and were also shown to suppress T cell proliferation in a dose-dependent manner. To ensure optimal donor selection, manufacturing optimization, and rigorous quality control, the rigorous Good Manufacturing Practice (GMP) conditions were utilized. The results indicated that hpMSCs increased rat survival rates and improved kidney function by decreasing serum creatinine, urea, potassium, and fractionated potassium levels. Furthermore, the study demonstrated that hpMSCs can prevent the initial stages of kidney structural fibrosis and improve kidney function in the early stages by mitigating late interstitial fibrosis and tubular atrophy. Additionally, a robust manufacturing process with consistent technical parameters was established.

Age- and gender-adjusted estimated glomerular filtration rate definition reveals hyperfiltration as a risk factor for renal function deterioration in type 2 diabetes

AIM

To assess the role of hyperfiltration for diabetic kidney disease (DKD) progression.

MATERIALS AND METHODS

A retrospective observational cohort study enrolled type 2 diabetes (T2D) patients with an initial estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73m2 or higher. Patients were categorized into two groups: hyperfiltration (eGFR exceeding the age- and gender-specific 95th percentile values from a prior national cohort study) and normofiltration. Rapid DKD progression was defined as an eGFR decline of more than 5 mL/min/1.73m2/year. We used a linear mixed effect model and Cox regression with time-varying covariate model to compare eGFR changes and identify factors associated with rapid DKD progression.

RESULTS

Of the enrolled 7563 T2D patients, 7.2% had hyperfiltration. The hyperfiltration group exhibited a higher rate of eGFR decline compared with the normofiltration group (-2.0 ± 0.9 vs. -1.1 ± 0.9 mL/min/1.73m2/year; P < .001). During an average follow-up period of 4.65 ± 3.86 years, 24.7% of patients with hyperfiltration experienced rapid DKD progression, compared with 15.7% of patients with normofiltration (P < .001). Cox regression analyses identified that initial hyperfiltration was a significant determinant of rapid DKD progression, with a hazard ratio of 1.66 (95% confidence interval: 1.41-1.95; P < .001). When combined with albuminuria, the risk of progression was further compounded (hazard ratio 1.76-3.11, all P < .001).

CONCLUSIONS

In addition to using the current Kidney Disease: Improving Global Outcomes CGA classification system, considering glomerular hyperfiltration status can improve the accuracy of predicting DKD progression.

Chemistry, Analysis, and Biological Aspects of Daprodustat, A New Hypoxia Inducible Factor Prolyl Hydroxylase Inhibitor: A Comprehensive Review

BACKGROUND

The National Health and Nutrition Examination Survey (NHANES) carried out a survey between 2007-10 and found that as compared to the general population, the prevalence of anemia in chronic kidney disease (CKD) patients was twice high. Daprodustat is an investigational novel drug for the treatment of renal anemia.

OBJECTIVE

The objective of this study is to provide a comprehensive review of chemistry, synthesis, pharmacology, pharmacokinetic, and bioanalytical methods for the analysis of Daprodustat.

METHODS

To improve understanding, a review was carried out by creating a database of relevant prior research from electronic sources such as ScienceDirect and PubMed. The methodology is shown in the flowchart of the literature selection process.

RESULTS

The drug was approved in 2020 for therapeutic purposes in Japan. It is a novel drug approved for the treatment of anemia in chronic kidney disease for oral administration. It is intended for adults who have undergone dialysis for a minimum of four months and are experiencing anemia as a result of chronic kidney disease.

CONCLUSION

This review examines therapeutic, pharmacological, and analytical aspects related to the novel drug Daprodustat.

Serum Urate Monitoring Among Older Adults With Gout: Initiating Urate-Lowering Therapy in Ontario, Canada

OBJECTIVE

To assess the proportion of, and factors associated with, older adults with gout receiving a serum urate (SUA) test after starting urate-lowering therapy (ULT).

METHODS

We performed a population-based retrospective cohort study in Ontario, Canada in patients ages ≥66 years with gout, newly dispensed ULT between 2010 and 2019. We characterized patients with SUA testing within 6 and 12 months after ULT dispensation. Multilevel logistic regression clustered by ULT prescriber evaluated the factors associated with SUA monitoring within 6 months.

RESULTS

We included 44,438 patients with a mean ± SD age of 76.0 ± 7.3 years and 64.4% male. Family physicians prescribed 79.1% of all ULTs. SUA testing was lowest in 2010 (56.4% at 6 months) and rose over time to 71.3% in 2019 (P < 0.0001). Compared with rheumatologists, family physicians (odds ratio [OR] 0.26 [95% confidence interval (95% CI) 0.23-0.29]), internists (OR 0.34 [95% CI 0.29-0.39]), nephrologists (OR 0.37 [95% CI 0.30-0.45]), and other specialties (OR 0.25 [95% CI 0.21-0.29]) were less likely to test SUA, as were male physicians (OR 0.87 [95% CI 0.83-0.91]). Patient factors associated with lower odds of SUA monitoring included rural residence (OR 0.81 [95% CI 0.77-0.86]), lower socioeconomic status (OR 0.91 [95% CI 0.85-0.97]), and patient comorbidities. Chronic kidney disease, hypertension, diabetes mellitus, and coprescription of colchicine/oral corticosteroids (OR 1.31 [95% CI 1.23-1.40]) were correlated with increased SUA testing.

CONCLUSION

SUA testing is suboptimal among older adults with gout initiating ULT but is improving over time. ULT prescriber, patient, and prescription characteristics were correlated with SUA testing.

Circulating extracellular vesicles in human cardiorenal syndrome promote renal injury in a kidney-on-chip system

BACKGROUNDCardiorenal syndrome (CRS) - renal injury during heart failure (HF) - is linked to high morbidity. Whether circulating extracellular vesicles (EVs) and their RNA cargo directly impact its pathogenesis remains unclear.METHODSWe investigated the role of circulating EVs from patients with CRS on renal epithelial/endothelial cells using a microfluidic kidney-on-chip (KOC) model. The small RNA cargo of circulating EVs was regressed against serum creatinine to prioritize subsets of functionally relevant EV-miRNAs and their mRNA targets investigated using in silico pathway analysis, human genetics, and interrogation of expression in the KOC model and in renal tissue. The functional effects of EV-RNAs on kidney epithelial cells were experimentally validated.RESULTSRenal epithelial and endothelial cells in the KOC model exhibited uptake of EVs from patients with HF. HF-CRS EVs led to higher expression of renal injury markers (IL18, LCN2, HAVCR1) relative to non-CRS EVs. A total of 15 EV-miRNAs were associated with creatinine, targeting 1,143 gene targets specifying pathways relevant to renal injury, including TGF-β and AMPK signaling. We observed directionally consistent changes in the expression of TGF-β pathway members (BMP6, FST, TIMP3) in the KOC model exposed to CRS EVs, which were validated in epithelial cells treated with corresponding inhibitors and mimics of miRNAs. A similar trend was observed in renal tissue with kidney injury. Mendelian randomization suggested a role for FST in renal function.CONCLUSIONPlasma EVs in patients with CRS elicit adverse transcriptional and phenotypic responses in a KOC model by regulating biologically relevant pathways, suggesting a role for EVs in CRS.TRIAL REGISTRATIONClinicalTrials.gov NCT03345446.FUNDINGAmerican Heart Association (AHA) (SFRN16SFRN31280008); National Heart, Lung, and Blood Institute (1R35HL150807-01); National Center for Advancing Translational Sciences (UH3 TR002878); and AHA (23CDA1045944).

Treatment satisfaction with molidustat in CKD-related anemia in non-dialysis patients: a post-hoc analysis of two clinical trials

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) are the standard treatment for patients with renal anemia to increase hemoglobin (Hb) levels and reduce the need for blood transfusions. However, treatments targeting high Hb levels require high doses of ESAs administered intravenously, which is associated with an elevated risk of adverse cardiovascular events. Furthermore, there have been some problems such as hemoglobin variability and low achievement of target hemoglobin due to the shorter half-lives of ESAs. Consequently, erythropoietin-promoting medications, such as hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, have been developed. This study aimed to evaluate changes in the Treatment Satisfaction Questionnaire for Medicine version II (TSQM-II) domain scores relative to baseline in each trial, to assess patient satisfaction with molidustat versus darbepoetin alfa.

METHODS

This post-hoc analysis of two clinical trials compared treatment satisfaction with an HIF-PH inhibitor, molidustat, versus a standard ESA, darbepoetin alfa, as part of therapy in patients with non-dialysis chronic kidney disease (CKD) and renal anemia.

RESULTS

Exploratory outcome data using the TSQM-II showed that both arms in both trials had enhanced treatment satisfaction over the course of the study period, as well as improvements in most TSQM-II domains at week 24 of treatment. Molidustat was associated with convenience domain scores at multiple time points depending on the trial. More patients were highly satisfied with the convenience of molidustat than that of darbepoetin alfa. Patients treated with molidustat had increased global satisfaction domain scores compared with those treated with darbepoetin alfa; however, the differences in global satisfaction domain scores were not significant.

CONCLUSION

These patient-reported satisfaction outcomes support the use of molidustat as a patient-centered treatment option for CKD-related anemia.

REGISTRATION OF CLINICAL TRIALS

ClinicalTrials.gov Identifier: NCT03350321 (November 22, 2017).

CLINICALTRIALS

gov Identifier: NCT03350347 (November 22, 2017).

Albuminuria and cardiovascular risk

Cardiovascular risk (CVR) estimation is a fundamental tool for guiding therapy. Albuminuria indicates target organ damage in an accessible, economic and non-invasive manner. Improves high-risk patient identification, especially in chronic kidney disease (CKD) and diabetes mellitus (DM). In addition, anti-albuminuric treatments may improve CVR. This would position albuminuria as a guide and therapeutic objective. Although the capacity of albuminuria as an epidemiological CVR marker in specific populations (hypertension, CKD, DM) is accepted, its profile as a risk marker in the general population and as a therapeutic target is controversial. There is ambiguous evidence regarding its predictive capacity, added to the fact that treatments such as SLGT2 blockers reduce CVR events regardless of albuminuria presence or magnitude. This review analyzes the available evidence on albuminuria as a CVR marker, a treatment goal and therapeutic guide.

CENtral blood pressure Targeting: a pragmatic RAndomized triaL in advanced Chronic Kidney Disease (CENTRAL-CKD): A Clinical Research Protocol

Background

Emerging data favor central blood pressure (BP) over brachial cuff BP to predict cardiovascular and kidney events, as central BP more closely relates to the true aortic BP. Considering that patients with advanced chronic kidney disease (CKD) are at high cardiovascular risk and can have unreliable brachial cuff BP measurements (due to high arterial stiffness), this population could benefit the most from hypertension management using central BP measurements.

Objective

To assess the feasibility and efficacy of targeting central BP as opposed to brachial BP in patients with CKD G4-5.

Design

Pragmatic multicentre double-blinded randomized controlled pilot trial.

Setting

Seven large academic advanced kidney care clinics across Canada.

Patients

A total of 116 adults with CKD G4-5 (estimated glomerular filtration rate [eGFR] < 30 mL/min) and brachial cuff systolic BP between 120 and 160 mm Hg. The key exclusion criteria are 1) ≥ 5 BP drugs, 2) recent acute kidney injury, myocardial infarction, stroke, heart failure or injurious fall, 3) previous kidney replacement therapy.

Methods

Double-blind randomization to a central or a brachial cuff systolic BP target (both < 130 mm Hg) as measured by a validated central BP device. The study duration is 12 months with follow-up visits every 2 to 4 months, based on local practice. All other aspects of CKD management are at the discretion of the attending nephrologist.

Outcomes

Primary Feasibility: Feasibility of a large-scale trial based on predefined components. Primary Efficacy: Carotid-femoral pulse wave velocity at 12 months. Others: Efficacy (eGFR decline, albuminuria, BP drugs, and quality of life); Events (major adverse cardiovascular events, CKD progression, hospitalization, mortality); Safety (low BP events and acute kidney injury).

Limitations

May be challenging to distinguish whether central BP is truly different from brachial BP to the point of significantly influencing treatment decisions. Therapeutic inertia may be a barrier to successfully completing a randomized trial in a population of CKD G4-5. These 2 aspects will be evaluated in the feasibility assessment of the trial.

Conclusion

This is the first trial to evaluate the feasibility and efficacy of using central BP to manage hypertension in advanced CKD, paving the way to a future large-scale trial.

Trial registration

clinicaltrials.gov (NCT05163158).

Effects of hypoxia-inducible factor prolyl hydroxylase inhibitors versus erythropoiesis-stimulating agents on iron metabolism and inflammation in patients undergoing dialysis: A systematic review and meta-analysis

Aims

This study aimed to evaluate the effects of hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) on iron metabolism and inflammation in dialysis-dependent chronic kidney disease (DD-CKD) patients.

Methods

PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov websites were searched for randomized controlled trials (RCTs) investigating HIF-PHIs versus ESAs for DD-CKD patients.

Key findings

Twenty studies with 14,737 participants were included in the meta-analysis, which demonstrated no significant difference in the effect of transferrin saturation and ferritin between HIF-PHIs and the ESAs group (MD, 0.65; 95%CI, -0.45 to 1.75; very low certainty; SMD, -0.03; 95% CI, -0.13 to 0.07; low certainty). However, HIF-PHIs significantly increased the iron (MD, 2.30; 95% CI, 1.40 to 3.20; low certainty), total iron-binding capacity (SMD, 0.82; 95% CI, 0.66 to 0.98; low certainty), and transferrin (SMD, 0.90; 95%CI, 0.74 to 1.05; moderate certainty) levels when compared with the ESAs group. In contrast, the hepcidin level and dosage of intravenous iron were significantly decreased in the HIF-PHIs group compared with the ESAs group (MD, -15.06, 95%CI, -21.96 to -8.16; low certainty; MD, -18.07; 95% CI, -30.05 to -6.09; low certainty). The maintenance dose requirements of roxadustat were independent of baseline CRP or hsCRP levels with respect to the effect on inflammation.

Significance

HIF-PHIs promote iron utilization and reduce the use of intravenous iron therapy. Furthermore, HIF-PHIs, such as roxadustat, maintain the erythropoietic response independent of the inflammatory state. Thus, HIF-PHIs may be an alternative treatment strategy for anemia in DD-CKD patients, where ESA is hyporesponsive due to iron deficiency and inflammation.

Can chronic kidney disease staging early predict outcome of large-artery ischemic stroke with impaired renal function?

Background

Ischemic stroke poses a major threat to human beings, and a prompt intravenous thrombolytic management remains the gold standard protocol for stroke sufferers. Although the role of thrombolytic therapy (r-tPA) for ischemic stroke patients and those with underlying impaired renal function has been advocated as effective treating strategy, there is still a lack of investigation as to finding out baseline important variables that are capable of early outcome prediction.

Objectives

In this project, we hypothesize that the change of clinical chronic kidney disease (CKD) staging (delta stage = CKD stage after 3-month follow-up - CKD stage at admission) could serve as a crucial predictor of the prognosis of patients.

Design

This is a cohort longitudinal retrospective study.

Sources and Methods

A total of 765 cerebral artery ischemic stroke patients with impaired renal function were recruited and followed up for 1 year. Among them, 116 had received the thrombolytic treatment (r-tPA) after being evaluated at the triage in the emergency department and the rest had not (non-r-tPA). Propensity-matching was applied to compare the mortality between the r-tPA and non-r-tPA groups. Multiple logistic regression (LR) and decision tree (DT) algorithm were used to identify important prediction factors for mortality as well as the improvement in neurological function.

Results

The 1-year mortality rates for r-tPA and non-r-tPA groups were 32.8% and 44.4%, respectively. The propensity-matched odds ratio of mortality for the r-tPA group compared with the non-r-tPA group is 0.469, with p = 0.003. Logistic regressions suggest that age, Hct, diabetes mellitus type 2, coronary artery disease, and delta stage are important factors for mortality for the non-r-tPA group, whereas age, diabetes mellitus type 2, chronic heart failure, hospital day, and delta stage are important factors for the r-tPA group. On the usage of antihypertensive drugs, ACEI/ARB was not associated with mortality (p = 0.198), whereas the diuretic was, with odds ratio at 1.619 (p = 0.025), indicating higher mortality after administration. Both LR and DT analyses indicate that delta stage is the most important predictor. For the r-tPA group, patients with delta stage ⩽0 had a 24% mortality, while that for delta stage >0 the mortality is 75%. For non-r-tPA patients, the corresponding mortalities were 30.9 and 66.3, respectively. Delta stage is also useful for predicting patients' improvement of neurological function, assessed by NIHSS, mRS, and Barthel Index. The areas under the curve for the three assessments are 0.83, 0.835, and 0.663, respectively.

Conclusion

Large-artery ischemic stroke patients who received thrombolytic treatment had significantly lower mortality, even when presenting underlying impaired renal function. The change of CKD staging (delta stage) is capable of acting as a powerful clinical baseline surrogate for both r-tPA and non-r-tPA patients in terms of early outcome prediction. Long-term use of diuretics could be potentially harmful to this group of patients. Moreover, delta stage correlates well with clinical long-term neurological functionality assessment (NIHSS, mRS, and Barthel index), which is helpful in aiding urgent clinical decision-making.

Physician Compliance with Computerized Clinical Decision Support System is a Complete Intermediate Factor in the Anemia Management of Patients with End-Stage Kidney Disease on Hemodialysis: A Retrospective Electronic Health Record Observational Study (Preprint)

BACKGROUND

Previous studies on clinical decision support systems (CDSSs) for the management of renal anemia in patients with end-stage kidney disease undergoing hemodialysis have previously focused solely on the effects of the CDSS. However, the role of physician compliance in the efficacy of the CDSS remains ill-defined.

OBJECTIVE

We aimed to investigate whether physician compliance was an intermediate variable between the CDSS and the management outcomes of renal anemia.

METHODS

We extracted the electronic health records of patients with end-stage kidney disease on hemodialysis at the Far Eastern Memorial Hospital Hemodialysis Center (FEMHHC) from 2016 to 2020. FEMHHC implemented a rule-based CDSS for the management of renal anemia in 2019. We compared the clinical outcomes of renal anemia between the pre- and post-CDSS periods using random intercept models. Hemoglobin levels of 10 to 12 g/dL were defined as the on-target range. Physician compliance was defined as the concordance of adjustments of the erythropoietin-stimulating agent (ESA) between the CDSS recommendations and the actual physician prescriptions.

RESULTS

We included 717 eligible patients on hemodialysis (mean age 62.9, SD 11.6 years; male n=430, 59.9%) with a total of 36,091 hemoglobin measurements (average hemoglobin and on-target rate were 11.1, SD 1.4, g/dL and 59.9%, respectively). The on-target rate decreased from 61.3% (pre-CDSS) to 56.2% (post-CDSS) owing to a high hemoglobin percentage of >12 g/dL (pre: 21.5%; post: 29%). The failure rate (hemoglobin <10 g/dL) decreased from 17.2% (pre-CDSS) to 14.8% (post-CDSS). The average weekly ESA use of 5848 (SD 4211) units per week did not differ between phases. The overall concordance between CDSS recommendations and physician prescriptions was 62.3%. The CDSS concordance increased from 56.2% to 78.6%. In the adjusted random intercept model, the post-CDSS phase showed increased hemoglobin by 0.17 (95% CI 0.14-0.21) g/dL, weekly ESA by 264 (95% CI 158-371) units per week, and 3.4-fold (95% CI 3.1-3.6) increased concordance rate. However, the on-target rate (29%; odds ratio 0.71, 95% CI 0.66-0.75) and failure rate (16%; odds ratio 0.84, 95% CI 0.76-0.92) were reduced. After additional adjustments for concordance in the full models, increased hemoglobin and decreased on-target rate tended toward attenuation (from 0.17 to 0.13 g/dL and 0.71 to 0.73 g/dL, respectively). Increased ESA and decreased failure rate were completely mediated by physician compliance (from 264 to 50 units and 0.84 to 0.97, respectively).

CONCLUSIONS

Our results confirmed that physician compliance was a complete intermediate factor accounting for the efficacy of the CDSS. The CDSS reduced failure rates of anemia management through physician compliance. Our study highlights the importance of optimizing physician compliance in the design and implementation of CDSSs to improve patient outcomes.

Death and Dialysis Following Discharge From Chronic Kidney Disease Clinic: A Retrospective Cohort Study

Background:

Multidisciplinary care is recommended for patients with advanced chronic kidney disease (CKD). A formalized, risk-based approach to CKD management is being adopted in some jurisdictions. In Ontario, Canada, the eligibility criteria for multidisciplinary CKD care funding were revised between 2016 and 2018 to a 2 year risk of kidney replacement therapy (KRT) greater than 10% calculated by the 4-variable Kidney Failure Risk Equation (KFRE). Implementation of the risk-based approach has led to the discharge of prevalent CKD patients.

Objective:

The primary objective of this study was to determine the frequency of occurrence of death and KRT initiation in patients discharged from CKD clinic.

Design:

Retrospective cohort study

Setting:

Single center multidisciplinary CKD clinic in Ontario, Canada

Patients:

Four hundred and twenty five patients seen at least once in 2013 at the multidisciplinary CKD clinic

Measurements:

Outcomes included discharge status, death, re-referral and KRT initiation. Reasons for discharge were recorded.

Methods:

Outcomes were extracted from available electronic medical records and the provincial death registry between the patient’s initial clinic visit in 2013 and January 1, 2020. KFRE-2 scores were calculated using the 4-variable KFRE equation. The hazard rates of death and KRT after discharge due to stable eGFR/low KFRE were compared to patients who remained in the clinic.

Results:

Of the 425 CKD patients, 69 (16%) and 19 (4%) were discharged to primary care and general nephrology, respectively. Of those discharged, 7 (8%) were re-referred to nephrology or CKD clinic, while only 2 (2%) discharged patients required subsequent KRT. The hazard of mortality was reduced after discharge from the clinic due to stable eGFR/low KFRE (adjusted HR = 0.45 [95% CI, 0.25-0.78, P = .005]).

Limitations:

Single center, observational retrospective study design and unknown kidney function over time post discharge for most patients

Conclusions:

Discharge of low risk patients from multidisciplinary CKD clinic appears feasible and safe, with fewer than 1 in 40 discharged patients subsequently initiated on KRT over the following 7 years.

Trends in nephrology referral patterns for patients with chronic kidney disease: Retrospective cohort study

Introduction

Information on early, guideline discordant referrals in nephrology is limited. Our objective was to investigate trends in referral patterns to nephrology for patients with chronic kidney disease (CKD).

Methods

Retrospective cohort study of adults with ≥1 visits to a nephrologist from primary care with ≥1 serum creatinine and/or urine protein measurement <180 days before index nephrology visit, from 2006 and 2019 in Alberta, Canada. Guideline discordant referrals were those that did not meet ≥1 of: Estimated glomerular filtration rate (eGFR) ˂ 30 mL/min/1.73m², persistent albuminuria (ACR ≥ 300 mg/g, PCR ≥ 500 mg/g, or Udip ≥ 2+), or progressive and persistent decline in eGFR until index nephrology visit (≥ 5 mL/min/1.73m²).

Results

Of 69,372 patients with CKD, 28,518 (41%) were referred in a guideline concordant manner. The overall rate of first outpatient visits to nephrology increased from 2006 to 2019, although guideline discordant referrals showed a greater increase (trend 21.9 per million population/year, 95% confidence interval 4.3, 39.4) versus guideline concordant referrals (trend 12.4 per million population/year, 95% confidence interval 5.7, 19.0). The guideline concordant cohort were more likely to be on renin-angiotensin system blockers or beta blockers (hazard ratio 1.14, 95% confidence interval 1.12, 1.16), and had a higher risk of CKD progression (hazard ratio 1.09, 95% confidence interval 1.06, 1.13), kidney failure (hazard ratio 7.65, 95% confidence interval 6.83, 8.56), cardiovascular event (hazard ratio 1.40, 95% confidence interval 1.35,1.45) and mortality (hazard ratio 1.58, 95% confidence interval 1.52, 1.63).

Conclusions

A significant proportion nephrology referrals from primary care were not consistent with current guideline-recommended criteria for referral. Further work is needed to identify quality improvement initiatives aimed at enhancing referral patterns of patients with CKD.

Association of Albuminuria and Regression of Chronic Kidney Disease in Adults With Newly Diagnosed Moderate to Severe Chronic Kidney Disease

IMPORTANCE

People with chronic kidney disease (CKD) are risk-stratified for adverse events based on estimated glomerular filtration rate (eGFR) and albuminuria level. CKD has often a favorable course (CKD regression) regardless of eGFR. Determining whether lower albuminuria is associated with CKD regression may have implications on CKD management.

OBJECTIVE

To assess the 5-year probability of CKD regression across albuminuria categories accounting for the competing risks of CKD progression and death in people with newly diagnosed CKD and the association between albuminuria level and CKD regression.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used administrative and laboratory data from Alberta, Canada, for adults with incident moderate to severe CKD (defined as sustained eGFR of 15-44 mL/min/1.73 m2 for >90 days), between April 1, 2008, and March 31, 2017, and albuminuria measures before cohort entry. Data analysis occurred in January to June 2022.

EXPOSURE

Albuminuria categories were defined by albumin to creatinine ratios (ACRs): A1 (ACR, <3 mg/mmol), A2 (ACR, 3-29 mg/mmol), A3<60 (ACR, 30-59 mg/mmol), and A3≥60 (ACR, ≥60 mg/mmol).

MAIN OUTCOMES AND MEASURES

The main outcome was time to the earliest of CKD regression or progression (sustained change in CKD stage for >3 months and ≥25% increase or decrease in eGFR from baseline or kidney failure, respectively), death, or censoring (outmigration or study end date: March 31, 2019). Cumulative incidence functions were used to estimate absolute risks, and cause-specific Cox models were used to assess the association between albuminuria and CKD regression, accounting for age, sex, eGFR, comorbidities, and health services use indicators.

RESULTS

Of 58 004 people with moderate to severe CKD (mean [SD] age, 77 [12] years; 31 725 [55%] women), 35 360 had A1 albuminuria (61%), 15 597 had A2 albuminuria (27%), 1527 had A3<60 albuminuria (3%), and 5520 had A3≥60 albuminuria (10%). Five-year probability of regression was highest with A1 (22.6%), followed by A2 (16.5%), and A3<60 (11.6%) and lowest with A3≥60 (5.3%). Using A1 albuminuria as the reference group, the hazard of regression was highest for A2 (hazard ratio [HR], 0.75; 95% CI, 0.72-0.79), then A3<60 (HR, 0.47; 95% CI, 0.40-0.54), and lowest for A3≥60 (HR, 0.27; 95% CI, 0.24-0.30).

CONCLUSIONS AND RELEVANCE

In this cohort study of people with moderate to severe CKD, albuminuria levels were inversely associated with CKD regression. These findings extend the key prognostic role of albuminuria, offering novel opportunities to discuss both favorable and adverse outcomes in people with CKD and inform CKD management.

Tight Blood Pressure Control in Chronic Kidney Disease

Hypertension affects over a billion people worldwide and is the leading cause of cardiovascular disease and premature death worldwide, as well as one of the key determinants of chronic kidney disease worldwide. People with chronic kidney disease and hypertension are at very high risk of renal outcomes, including progression to end-stage renal disease, and, even more importantly, cardiovascular outcomes. Hence, blood pressure control is crucial in reducing the human and socio-economic burden of renal and cardiovascular outcomes in those patients. However, current guidelines from hypertension and renal societies have issued different and sometimes conflicting recommendations, which risk confusing clinicians and potentially contributing to a less effective prevention of renal and cardiovascular outcomes. In this review, we critically appraise existing evidence and key international guidelines, and we finally formulate our own opinion that clinicians should aim for a blood pressure target lower than 130/80 in all patients with chronic kidney disease and hypertension, unless they are frail or with multiple comorbidities. We also advocate for an even more ambitious systolic blood pressure target lower than 120 mmHg in younger patients with a lower burden of comorbidities, to minimise their risk of renal and cardiovascular events during their lifetime.

Impact of quality improvement initiatives to improve CKD referral patterns: a systematic review protocol

INTRODUCTION

Chronic kidney disease (CKD) is a global-health problem. A significant proportion of referrals to nephrologists for CKD management are early and guideline-discordant, which may lead to an excess number of referrals and increased wait-times. Various initiatives have been tested to increase the proportion of guideline-concordant referrals and decrease wait times. This paper describes the protocol for a systematic review to study the impacts of quality improvement initiatives aimed at decreasing the number of non-guideline concordant referrals, increasing the number of guideline-concordant referrals and decreasing wait times for patients to access a nephrologist.

METHODS AND ANALYSIS

We developed this protocol by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols (2015). We will search the following empirical electronic databases: MEDLINE, Embase, Cochrane Library, CINAHL, Web of Science, PsycINFO and grey literature for studies designed to improve guideline-concordant referrals or to reduce unnecessary referrals of patients with CKD from primary care to nephrology. Our search will include all studies published from database inception to April 2021 with no language restrictions. The studies will be limited to referrals for adult patients to nephrologists. Referrals of patients with CKD from non-nephrology specialists (eg, general internal medicine) will be excluded.

ETHICS AND DISSEMINATION

Ethics approval will not be required, as we will analyse data from studies that have already been published and are publicly accessible. We will share our findings using traditional approaches, including scientific presentations, open access peer-reviewed platforms, and appropriate government and public health agencies.

PROSPERO REGISTRATION NUMBER

CRD42021247756.

Independent External Validation and Comparison of Death and Kidney Replacement Therapy Prediction Models in Advanced CKD

Rationale & Objective

Study Design

Setting & Participants

Outcomes & Analytical Approach

Results

Limitations

Conclusions

Comparative risk of new-onset hyperkalemia for antihypertensive drugs in patients with diabetic nephropathy: A Bayesian network meta-analysis

Several randomised controlled trials (RCTs) have evaluated the risk of hyperkalemia of antihypertensive drugs on diabetic nephropathy, yet the results are conflicting. We searched MEDLINE, Embase, The Cochrane Library, and Web of Science for RCTs investigating the risk of antihypertensive drugs on hyperkalemia in diabetic nephropathy from inception to May 31, 2020. Direct comparative meta-analysis showed that the proportion of patients with hyperkalemia was significantly higher in the ARB, aldosterone antagonist, renin inhibitor group than in the placebo group. Moreover, the risk of hyperkalemia in the ARB group was higher than that in the CCB group. Network meta-analysis showed the risk of hyperkalemia in the ARB, aldosterone antagonist, and renin inhibitor group was higher than in the placebo group, but there was no statistical difference between the CCB, ACEI, β blocker, endothelin inhibitor, and diuretic groups than in the placebo group. The possibility of antihypertensive drugs in risk of hyperkalemia being the worst treatment was aldosterone antagonist (98.8%), followed by ARB (73.8%), renin inhibitor (63.8%), diuretic (53.1%), ACEI (46.9%), β blocker (36.8%), endothelin inhibitor (35.2%), placebo (27.1%), and finally CCB (14.3.1%). Therefore, aldosterone antagonist seems worse than other antihypertensive drugs in the risk of hyperkalemia in patients with diabetic nephropathy.

Acute kidney injury may impede results after transcatheter aortic valve implantation

INTRODUCTION

Severe complications after transcatheter aortic valve implantation (TAVI) are rare due to increasing procedural safety. However, TAVI procedure-related haemodynamic instability and increased risk of infection may affect renal functional reserve with subsequent renal acidosis and hyperkalaemia.

OBJECTIVE

In this study, we investigated incidence, modifiable risk factors and prognosis of acute kidney injury (AKI) and AKI complicated by hyperkalaemia, pulmonary oedema or metabolic acidosis after TAVI.

METHODS

In a retrospective single-centre study, 804 consecutive patients hospitalized during 2017 and 2018 for elective TAVI were included. AKI was defined according to the 'Kidney Disease Improving Global Outcome' (KDIGO) initiative. Variables on co-morbidities, intra-/post-interventional complications and course of renal function up to 6 months after index-hospitalization were assessed. In multivariate regression analyses, risk factors for the development of AKI, complicated AKI, renal non-recovery from AKI and in-hospital mortality were determined.

RESULTS

Incidence of AKI was 13.8% (111/804); in-hospital mortality after TAVI was 2.3%. AKI was an independent risk factor for in-hospital mortality, odds ratio (OR) 10.3 (3.4-31.6), P < 0.001, further increasing to OR = 21.8 (6.6-71.5), P < 0.001 in patients with AKI complicated by hyperkalaemia, pulmonary oedema or metabolic acidosis, n = 57/111 (51.4%). Potentially modifiable, interventional factors independently associated with complicated AKI were infection [OR = 3.20 (1.61-6.33), P = 0.001] and red blood cell transfusion [OR = 5.04 (2.67-9.52), P < 0.001]. Valve type and size, contrast volume and other intra-interventional characteristics, such as the need for tachycardial pacing, did not influence the development of AKI. Eleven of 111 (9.9%) patients did not recover from AKI, mostly affecting patients with cardiac decompensation. In 18/111 (16.2%) patients, information concerning AKI was provided in discharge letter. Within 6 months after TAVI, higher proportion of patients with AKI showed progression of pre-existing chronic kidney disease compared with patients without AKI [14/29, 48.3% versus 54/187, 28.9%, OR = 2.3 (95% confidence interval 1.0-5.1), P = 0.036].

CONCLUSIONS

AKI is common and may impede patient outcome after TAVI with acute complications such as hyperkalaemia or metabolic acidosis and adverse renal function until 6 months after intervention. Our study findings may contribute to refinement of allocation of appropriate level of care in and out of hospital after TAVI.

Investigating the Relationship Between Age and Kidney Failure in Adults With Category 4 Chronic Kidney Disease

Background:

In people with severe chronic kidney disease (CKD), there is an inverse relationship between age and kidney failure. If this relationship is the same at any age (linear), one effect (hazard ratio) will be sufficient for accurate risk prediction; if it is nonlinear, the effect will vary with age.

Objective:

To investigate the relationship between age and kidney failure in adults with category G4 chronic kidney disease (G4 CKD).

Methods:

We performed a population-based study using linked administrative databases in Alberta, Canada, to study adults with G4 CKD (estimated glomerular filtration rate [eGFR] = 15-30 mL/min/1.73 m²) and without previously documented eGFR <15 mL/min/1.73 m² or renal replacement. We used cause-specific Cox regression to model the relationship between age and the hazard of kidney failure (the earlier of eGFR <10 mL/min/1.73 m² or receipt of renal replacement) and death, incorporating spline terms to capture any nonlinear effect of age. We included sex, diabetes mellitus, cardiovascular disease, albuminuria, and eGFR in all models.

Results:

Of the 27 823 participants (97 731 patient-years at risk; mean age = 76 years, ±13), 19% developed kidney failure and 51% died. The decline in the hazard of kidney failure associated with a given increase in age was not constant but became progressively larger as people aged; that is, the hazard ratio became progressively smaller (closer to 0). Assuming an eGFR of 25 mL/min/1.73 m², for every 10-year increase in age, the hazard ratio declined from 0.76 (95% confidence interval = 0.73-0.79) at age 50 years to 0.43 (95% confidence interval = 34-56) at age 80 years in people without cardiovascular disease, and from 0.75 (95% confidence interval = 0.70-0.79) at age 50 years to 0.36 (95% confidence interval = 0.29-0.45) at age 80 years in people with cardiovascular disease.

Conclusions:

The relationship between kidney failure and age varies with age. An age-dependent effect, rather than a constant effect, needs to be specified to accurately predict risk. These findings have implications for risk prediction and advanced care planning.

Sex-Specific Associations of Risks and Cardiac Structure and Function With Microalbumin/Creatinine Ratio in Diastolic Heart Failure

Background: Heart failure with preserved ejection fraction (HFpEF) affects women more frequently than men. However, data on sex-specific associations of adverse health outcomes and left ventricular structure and function and with microalbuminuria in patients with HFpEF are scarce. Methods: In 1,334 participants enrolled in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) Trial, we estimated the sex-specific multivariable-adjusted risk and LV traits with urine microalbumin/creatine ratio (ACR), using Cox or linear regression. Results: In total, 604 (45.3%) were women. In multivariable-adjusted analyses, a doubling of ACR in both men and women was associated with higher posterior (+0.014 cm, p = 0.012/+0.012 cm, p = 0.033) wall thickness and left ventricular mass index (+2.55 mg/m2, p = 0.004/+2.45 mg/m2, p = 0.009), whereas was also associated with higher septal (+0.018 cm, p = 0.002) and left atrial volume index (+1.44 mL/m2, p = 0.001) in men. ACR was a key predictor of all-cause (HR, 1.11; p = 0.006) and cardiovascular (HR, 1.17; p = 0.002) death in women, whereas in men ACR was associated with HF hospitalization (HR, 1.23; p < 0.001), any hospitalization (HR, 1.06; p = 0.006), and myocardial infarction (HR, 1.19; p = 0.017). The interactions of sex with ACR were significant for hospitalization for heart failure and any hospitalization (p ≤ 0.034). Conclusions: Outcomes and cardiac structure and function in patients with HFpEF appear to be influenced by ACR that vary according to sex. In men, ACR was significant associated with LV diastolic function, hospitalization, and myocardial infarction, whereas in women was associated with mortality.

Interlaboratory bias of albuminuria and proteinuria in hypertensive pregnancy

BACKGROUND

Measurement of proteinuria in women with hypertensive disorders of pregnancy is of major importance in the diagnosis and management of preeclampsia. Urinary protein/creatinine ratio, which is commonly used to detect kidney damage in preeclampsia, suffers from important analytical limitations, including poor harmonization of results between laboratories. Adoption of albuminuria could help reduce interlaboratory bias, since methods used to quantify it are better harmonized.

METHODS

A total of 27 urinary samples collected from hypertensive women evaluated for preeclampsia were sent to four different clinical laboratories in Canada. Urinary proteins and albumin as well as urinary creatinine were measured in duplicates in one batch to calculate protein/creatinine (PCR) and albumin/creatinine (ACR) ratio. Statistical analyses were done to evaluate interlaboratory variability of urinary proteins and urinary albumin.

RESULTS

Interlaboratory bias for urinary proteins ranged from 64.7% at low concentration to 3.9% at higher concentrations. In contrast, urinary albumin interlaboratory bias ranged from 29.2% to 4% from low to high concentrations. Coefficient of variation for urinary proteins reached a maximum of 91.5% in lower concentration while urinary albumin highest value was 42.7%. When looking at PCR and ACR ratio, eight samples had PCR measurement range that contained the diagnostic threshold used to detect kidney damage in HDP (30 mg/mmol), while only four samples had ACR ratio measurement range that contained the diagnostic threshold used outside of pregnancy in Canada (2 mg/mmol).

CONCLUSION

Interlaboratory bias was lower for urinary albumin measurement compared to urinary proteins in hypertensive women evaluated for preeclampsia. Better harmonization with the use of albumin instead of protein measurement would reduce instances where results of different laboratories lead to opposite diagnosis of kidney damage in pregnancy.

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder

Purpose of review:

(1) To provide commentary on the 2017 update to the Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD); (2) to apply the evidence-based guideline update for implementation within the Canadian health care system; (3) to provide comment on the care of children with chronic kidney disease (CKD); and (4) to identify research priorities for Canadian patients.

Sources of information:

The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD.

Methods:

The commentary committee co-chairs selected potential members based on their knowledge of the Canadian kidney community, aiming for wide representation from relevant disciplines, academic and community centers, and different geographical regions.

Key findings:

We agreed with many of the recommendations in the clinical practice guideline on the diagnosis, evaluation, prevention, and treatment of CKD-MBD. However, based on the uncommon occurrence of abnormalities in calcium and phosphate and the low likelihood of severe abnormalities in parathyroid hormone (PTH), we recommend against screening and monitoring levels of calcium, phosphate, PTH, and alkaline phosphatase in adults with CKD G3. We suggest and recommend monitoring these parameters in adults with CKD G4 and G5, respectively. In children, we agree that monitoring for CKD-MBD should begin in CKD G2, but we suggest measuring ionized calcium, rather than total calcium or calcium adjusted for albumin. With regard to vitamin D, we suggest against routine screening for vitamin D deficiency in adults with CKD G3-G5 and G1T-G5T and suggest following population health recommendations for adequate vitamin D intake. We recommend that the measurement and management of bone mineral density (BMD) be according to general population guidelines in CKD G3 and G3T, but we suggest against routine BMD testing in CKD G4-G5, CKD G4T-5T, and in children with CKD. Based on insufficient data, we also recommend against routine bone biopsy in clinical practice for adults with CKD or CKD-T, or in children with CKD, although we consider it an important research tool.

Limitations:

The committee relied on the evidence summaries produced by KDIGO. The CSN committee did not replicate or update the systematic reviews.

Reliability of urinalysis for identification of proteinuria is reduced in the presence of other abnormalities including high specific gravity and hematuria

PURPOSE

Chronic kidney disease (CKD) is classified according to cause, glomerular filtration rate, and proteinuria. Identification of proteinuria with urinalysis (UA) is less accurate than quantification via other methods. We investigated factors leading to discordant UA findings when compared against paired albumin-to-creatinine ratio (ACR) testing.

METHODS

Four thousand three hundred and twenty-three UAs were grouped by proteinuria level (A1-A3); concordance with ACR was examined. Classification of UA with confounding factors (UA+CF) or without (UA-CF) was based on CF that resulted in >10% increase in false-positive proteinuria readings. The presence of ≥3+ blood, ≥3+ leukocyte esterase, any ketonuria, specific gravity ≥1.020, ≥1+ urobilinogen, ≥2+ bilirubin, ≥2+ bacteria, ≥3 RBC/hpf (high powered field), ≥10 WBC/hpf, and/or ≥6 epithelial cells/hpf led to UA+CF classification.

RESULTS

Proteinuria was determined to be present in 14.1% by UA dipstick and 24.9% by ACR. Using ACR as the standard, overall concordance was 80.4%, with 17.2% false-negatives and 2.3% false-positives by UA. UA+CF represented 55.6% of UA overall (n = 2404), and 98.0% of those false-positive for proteinuria. High specific gravity and hematuria are the strongest predictors of false positives. For A2 proteinuria (30-300 mg/g, 1+,2+,3+ on UA) UA-CF had a higher negative predictive value (NPV) (99.8%) than UA+CF (77.6%); NPV for A3 proteinuria (>300 mg/g, 4+ on UA) was 100% for UA-CF and UA+CF.

CONCLUSION

Additional abnormalities were noted in >50% of outpatient UAs indicating proteinuria. Given the significant proportion of patients having a false-positive UA for proteinuria when these CFs were present, we recommend that such patients undergo ACR confirmatory testing, according to a clinical algorithm for the incorporation of UA results into the management of CKD.

Cardiorenal syndrome in thalassemia patients

Background

Cardiorenal syndrome (CRS), a serious condition with high morbidity and mortality, is characterized by the coexistence of cardiac abnormality and renal dysfunction. There is limited information about CRS in association thalassemia. This study aimed to investigate the prevalence of CRS in thalassemia patients and also associated risk factors.

Methods

Thalassemia patients who attended the out-patient clinic of a tertiary care university hospital from October 2016 to September 2017 were enrolled onto this cross-sectional study. Clinical and laboratory findings from 2 consecutive visits, 3 months apart, were assessed. The criteria for diagnosis of CRS was based on a system proposed by Ronco and McCullough. Cardiac abnormalities are assessed by clinical presentation, establishment of acute or chronic heart failure using definitions from 2016 ESC guidelines or from structural abnormalities shown in an echocardiogram. Renal dysfunction was defined as chronic kidney disease according to the 2012 KDIGO guidelines.

Results

Out of 90 thalassemia patients, 25 (27.8%) had CRS. The multivariable analysis showed a significant association between CRS and extramedullary hematopoiesis (EMH) (odds ratio (OR) 20.55, p = 0.016); thalassemia type [β⁰/β^E vs β⁰/β⁰ thalassemia (OR 0.005, p = 0.002)]; pulmonary hypertension (OR 178.1, p = 0.001); elevated serum NT-proBNP (OR 1.028, p = 0.022), and elevated 24-h urine magnesium (OR 1.913, p = 0.016). There was no association found between CRS and frequency of blood transfusion, serum ferritin, liver iron concentration, cardiac T2*, type of iron chelating agents, or urine neutrophil gelatinase-associated lipocalin level.

Conclusions

CRS is relatively common in thalassemia patients. Its occurrence is associated with laboratory parameters which are easily measured in clinical practice.

Elevated suPAR Is an Independent Risk Marker for Incident Kidney Disease in Acute Medical Patients

Introduction

Identifying patients at high risk of developing kidney disease could lead to early clinical interventions that prevent or slow disease progression. Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory biomarker thought to be involved in the pathogenesis and development of kidney disease. We aimed to determine whether elevated plasma suPAR measured at hospital admission is associated with incident kidney disease in patients presenting to the emergency department.

Materials and Methods

This was a retrospective registry-based cohort study performed at the Emergency Department of Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark. Patients were included in the study from November 2013 to March 2017 and followed until June 2017. Patients were excluded if they were diagnosed with kidney disease or died prior to index discharge. Plasma suPAR was measured at hospital admission, and the main outcome was time to incident kidney disease, defined by ICD-10 diagnosis codes for both chronic and acute kidney conditions. Association between suPAR and time to incident kidney disease was assessed by Cox proportional hazard regression analysis.

Results

In total, 25,497 patients (median age 58.1 years; 52.5% female) were admitted to the emergency department and followed for development of kidney disease. In multivariable Cox regression analysis adjusting for age, sex, eGFR, CRP, cardiovascular disease, hypertension, and diabetes, each doubling in suPAR at hospital admission was associated with a hazard ratio of 1.57 (95% CI: 1.38–1.78, P < 0.001) for developing a chronic kidney condition and 2.51 (95% CI: 2.09–3.01, P < 0.001) for developing an acute kidney condition.

Discussion

In a large cohort of acutely hospitalized medical patients, elevated suPAR was independently associated with incident chronic and acute kidney conditions. This highlights the potential for using suPAR in risk classification models to identify high-risk patients who could benefit from early clinical interventions. The main limitation of this study is its reliance on accurate reporting of ICD-10 codes for kidney disease.

The Impact of a New Triage and Booking System on Renal Clinic Wait Times

Background:

Prolonged wait times are known barriers to accessing nephrology care for patients needing more urgent specialist services. Improved process and standardized triage systems are known to minimize wait times of urgent or semi-urgent care in health care disciplines. In Central Zone (CZ) renal clinic, mean wait times for urgent (P1) and semi-urgent (P2) referrals were prolonged before 2014. We also observed prolonged wait times for elective (P3-P5) categories. Improving wait times was identified as an access to care quality improvement focus in CZ renal clinic of the Nova Scotia Health Authority (NSHA).

Objectives:

To describe our new referral process and new triage system, and to examine their effect on number of referrals wait-listed and mean wait times.

Design:

A quasi-experimental design was used.

Setting:

Halifax, Nova Scotia, Canada.

Participants:

Patients referred to Central Zone Renal Clinic between 2012 and 2018.

Measurements:

A time series of referral counts and wait times for each triage category were measured before our interventions and after implementing our interventions.

Methods:

We reviewed our referral processes to identify gaps leading to prolonged wait times. On January 1, 2014, we implemented new administrative procedures: pretriage (standardized referral information form and staff training), triage (standardized clinic intake criteria and new triage guidelines), posttriage (protecting clinic spots for urgent and semi-urgent referrals, wait-list maintenance, and increasing new referral clinic capacity). Data were collected prospectively. Descriptive analysis on mean wait times was done using run charts.

Results:

A 33% reduction in total number of referrals wait-listed was observed over 4.5 years after intervention. Descriptive analysis of the urgent and semi-urgent categories (P1 and P2) revealed a significant shift of mean wait times on run charts after the interventions. Target wait time was achieved in 94% of P1 category and 78% of P2 category.

Limitations:

This type of study design does not exclude confounding variables influencing results. We did not explore stakeholder satisfaction or whether the new referral process presented barriers to resending referrals that had insufficient triage data. The long-term sustainability of adding demand-responsive surge clinics and opportunity cost were not assessed. Our referral process and triage system have not been externally validated and may not be applicable in settings without wait-lists or settings that use electronic, telephone or telemedicine consults.

Conclusion:

Our selective intake of referrals with adequate triage information and referrals needing nephrology consult as defined by our clinic intake criteria reduced number of referrals wait-listed. We saw improved wait times for urgent and semi-urgent referrals with these categories now falling within target wait times for the vast majority of patients. The work of this improvement initiative continues especially for the lower-risk triage categories.

Trial registration:

Not applicable as this was a Quality improvement initiative.

Community Pharmacy-Based eGFR Screening for Early Detection of CKD in High Risk Patients

BACKGROUND

Chronic kidney disease (CKD) is a condition presenting with long-term slow progression of structural and/or functional damage to the kidneys. Early detection is key to preventing complications and improving outcomes. Point-of-care estimated glomerular filtration rate (eGFR) screening technology allows for detection of abnormal kidney function in the community pharmacy setting.

OBJECTIVE

To evaluate the effectiveness of a community pharmacist-directed point-of-care screening program and to identify the prevalence of CKD in high-risk patients.

DESIGN

Quantitative observational.

SETTING

Four community pharmacies in British Columbia over a 6-month period.

PATIENTS

In all, 642 participants with at least one CKD risk factor were identified and screened. Mean age was 60 years and females accounted for 55% of the study population.

MEASUREMENTS

Serum creatinine was measured from peripheral blood using the HeathTab® screening system (Piccolo® Renal Function Panel with the Piccolo® blood chemistry analyzer). eGFR was calculated according to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula.

METHODS

Patients provided a sample of peripheral blood via a self-administered finger-prick and analytical data to assess kidney function was reported including blood urea nitrogen (BUN), serum creatinine, and electrolytes by the HealthTab® screening system. Once results were available, the pharmacist conducted a comprehensive medication review with the patient and recommended certain follow-up actions if appropriate.

RESULTS

CKD risk factor included diabetes (30%), hypertension (45%), cardiovascular disease (12%), family history of kidney disease (13%), age over 55 years (68%), and an Aboriginal, Asian, South Asian, or African ethnic background (82%). A total of 11.5% of patients had eGFR values lower than 60 mL/min (abnormal renal function) and 34% had an eGFR between 60 and 89 mL/min (minimally reduced renal function). Overall pharmacists' actions included blood pressure check (98%), education on CKD and risk factors (89%), medication review (72%), and physician follow-up (38%). Limitations included lack of follow-up beyond the 3-month study period prevented medical confirmation of CKD and limited the ability to quantify the impact of pharmacist interventions on the clinical outcomes of patients with low eGFR.

CONCLUSION

These results illustrate the prevalence of abnormal renal function among undiagnosed, high-risk patients in the community. Pharmacists, as the most accessible healthcare practitioners, are ideally positioned to utilize novel point-of care technologies to improve access to CKD screening, facilitate follow-up, and increase awareness around the importance of early detection.

NAFLD as a driver of chronic kidney disease

Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are worldwide public health problems, affecting up to 25-30% (NAFLD), and up to 10-15% (CKD) of the general population. Recently, it has also been established that there is a strong association between NAFLD and CKD, regardless of the presence of potential confounding diseases such as obesity, hypertension and type 2 diabetes. Since NAFLD and CKD are both common diseases that often occur alongside other metabolic conditions, such as type 2 diabetes or metabolic syndrome, elucidating the relative impact of NAFLD on the risk of incident CKD presents a substantial challenge for investigators working in this research field. A growing body of epidemiological evidence suggests that NAFLD is an independent risk factor for CKD and recent evidence also suggests that associated factors such as metabolic syndrome, dysbiosis, unhealthy diets, platelet activation and processes associated with ageing could also contribute mechanisms linking NAFLD and CKD. This narrative review provides an overview of the literature on: a) the evidence for an association and causal link between NAFLD and CKD and b) the underlying mechanisms by which NAFLD (and factors strongly linked with NAFLD) may increase the risk of developing CKD.

Preventing CKD in Developed Countries

Chronic kidney disease (CKD) is an important public health concern in developed countries because of both the number of people affected and the high cost of care when prevention strategies are not effectively implemented. Prevention should start at the governance level with the institution of multisectoral polices supporting sustainable development goals and ensuring safe and healthy environments. Primordial prevention of CKD can be achieved through implementation of measures to ensure healthy fetal (kidney) development. Public health strategies to prevent diabetes, hypertension, and obesity as risk factors for CKD are important. These approaches are cost-effective and reduce the overall noncommunicable disease burden. Strategies to prevent nontraditional CKD risk factors, including nephrotoxin exposure, kidney stones, infections, environmental exposures, and acute kidney injury (AKI), need to be tailored to local needs and epidemiology. Early diagnosis and treatment of CKD risk factors such as diabetes, obesity, and hypertension are key for primary prevention of CKD. CKD tends to occur more frequently and to progress more rapidly among indigenous, minority, and socioeconomically disadvantaged populations. Special attention is required to meet the CKD prevention needs of these populations. Effective secondary prevention of CKD relies on screening of individuals at risk to detect and treat CKD early, using established and emerging strategies. Within high-income countries, barriers to accessing effective CKD therapies must be recognized, and public health strategies must be developed to overcome these obstacles, including training and support at the primary care level to identify individuals at risk of CKD, and appropriately implement clinical practice guidelines.

Impact of the KidneyWise toolkit on chronic kidney disease referral practices in Ontario primary care: a prospective evaluation

OBJECTIVES

Chronic kidney disease (CKD) is common; therefore, coordination of care between primary care and nephrology is important. Ontario Renal Network's KidneyWise toolkit was developed to provide guidance on the detection and management of people with CKD in primary care (www.kidneywise.ca). The aim of this study was to evaluate the impact of the April 2015 KidneyWise toolkit release on the characteristics of primary care referrals to nephrology.

DESIGN AND SETTING

The study was a prospective pre-post design conducted at two nephrology sites (community site: Trillium Health Partners in Mississauga, Ontario, Canada, and academic site: St Joseph's Healthcare in Hamilton, Ontario, Canada). Referrals were compared during the 3-month time period immediately prior to, and during a 3-month period 1 year after, the toolkit release.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the change in proportion of referrals for CKD that met the KidneyWise criteria. Additional secondary referral and quality of care outcomes were also evaluated. Multivariable logistic regression was used to evaluate preselected variables for their independent association with referrals that met the KidneyWise criteria.

RESULTS

The proportion of referrals for CKD among people who met the KidneyWise referral criteria did not significantly change from pre-KidneyWise to post-KidneyWise implementation (44.7% vs 45.8%, respectively, adjusted OR 1.16, 95% CI 0.85 to 1.59, p=0.36). The proportion of referrals for CKD that provided a urine albumin-creatinine ratio significantly increased post-KidneyWise (25.8% vs 43.8%, adjusted OR 1.45, 95% CI 1.06 to 1.97, p=0.02). The significant independent predictors of meeting the KidneyWise referral criteria were academic site, increased age and use of the KidneyWise referral form.

CONCLUSIONS

We did not observe any change in the proportion of appropriate referrals for CKD at two large nephrology centres 1 year after implementation of the KidneyWise toolkit.

Evaluation of administrative case definitions for chronic kidney disease in children

INTRODUCTION

Administrative data is increasingly used for chronic disease surveillance; however, its validity to define cases of chronic kidney disease (CKD) in children is unknown. We sought to evaluate the performance of case definitions for CKD in children.

METHODS

We utilized population-based administrative data from the Manitoba Center for Health Policy to evaluate the validity of algorithms based on a combination of hospital claims, outpatient physician visits, and pharmaceutical use over 1-3 years in children <18 years of age. Algorithms were compared with a laboratory-based definition (estimated glomerular filtration rate < 90 ml/min/1.73 m² and/or presence of proteinuria).

RESULTS

All algorithms evaluated had very low sensitivity (0.20-0.39) and moderate positive predictive value (0.52-0.68). Algorithms had excellent specificity (0.98-0.99) and negative predictive value (0.96-0.97). Receiver operating characteristic (ROC) curves indicate fair accuracy (0.60-0.68). Sensitivity improved with increasing years of data. One or more physician claims and one or more prescriptions over 3 years had the highest sensitivity and ROC.

CONCLUSIONS

The sensitivity of administrative data algorithms for CKD is unacceptably low for a screening test. Specificity is excellent; therefore, children without CKD are correctly identified. Alternate data sources are required for population-based surveillance of this important chronic disease.

Quality of Chronic Kidney Disease Management in Canadian Primary Care

IMPORTANCE

Although patients with chronic kidney disease (CKD) are routinely managed in primary care settings, no nationally representative study has assessed the quality of care received by these patients in Canada.

OBJECTIVE

To evaluate the current state of CKD management in Canadian primary care practices to identify care gaps to guide development and implementation of national quality improvement initiatives.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study leveraged Canadian Primary Care Sentinel Surveillance Network data from January 1, 2010, to December 31, 2015, to develop a cohort of 46 162 patients with CKD managed in primary care practices. Data analysis was performed from August 8, 2018, to July 31, 2019.

MAIN OUTCOMES AND MEASURES

The study examined the proportion of patients with CKD who met a set of 12 quality indicators in 6 domains: (1) detection and recognition of CKD, (2) testing and monitoring of kidney function, (3) use of recommended medications, (4) monitoring after initiation of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs), (5) management of blood pressure, and (6) monitoring for glycemic control in those with diabetes and CKD. The study also analyzed associations of divergence from these quality indicators.

RESULTS

The cohort comprised 46 162 patients (mean [SD] age, 69.2 [14.0] years; 25 855 [56.0%] female) with stage 3 to 5 CKD. Only 4 of 12 quality indicators were met by 75% or more of the study cohort. These indicators were receipt of an outpatient serum creatinine test within 18 months after confirmation of CKD, receipt of blood pressure measurement at any time during follow-up, achieving a target blood pressure of 140/90 mm Hg or lower, and receiving a hemoglobin A1c test for monitoring diabetes during follow-up. Indicators in the domains of detection and recognition of CKD, testing and monitoring of kidney function (specifically, urine albumin to creatinine ratio testing), use of recommended medications, and appropriate monitoring after initiation of treatment with ACEIs or ARBs were not met. Only 6529 patients (18.4%) with CKD received a urine albumin test within 6 months of CKD diagnosis, and 3954 (39.4%) had a second measurement within 6 months of an abnormal baseline urine albumin level. Older age (≥85 years) and CKD stage 5 were significantly associated with not satisfying the criteria for the quality indicators across all domains. Across age categories, younger patients (aged 18-49 years) and older patients (≥75 years) were less likely to be tested for albuminuria (314 of 1689 patients aged 18-49 years [18.5%], 1983 of 11 919 patients aged 75-84 years [61.6%], and 614 of 5237 patients aged ≥85 years [11.7%] received the urine albumin to creatinine ratio test within 6 months of initial estimated glomerular filtration rate <60 mL/min per 1.73 m2; P < .001). Patients aged 18 to 49 years were less commonly prescribed recommended medications (222 of 2881 [7.7%]), whereas patients aged 75 to 84 years were prescribed ACEIs or ARBs most frequently (2328 of 5262 [44.2%]; P < .001).

CONCLUSIONS AND RELEVANCE

The findings suggest that management of CKD across primary care practices in Canada varies according to quality indicator. This study revealed potential priority areas for quality improvement initiatives in Canadian primary care practices.

High rates of protein intake are associated with an accelerated rate of decline of residual kidney function in incident peritoneal dialysis patients

BACKGROUND

Preservation of residual kidney function (RKF) is a relevant objective in peritoneal dialysis (PD) patients. The influence of dietary protein intake (PI) on this variable has not been adequately investigated.

METHODS

Following an observational design, we studied 336 patients incident on PD, with a minimum follow-up of 6 months. The main study variable was the mean PI [normalized rate of protein nitrogen appearance (nPNA)] during the first 4 months on PD. The main outcome variables were the absolute rate of decline of RKF and the proportion of patients presenting a >50% decay of their RKF during the first year of follow-up. We applied univariate and multivariate strategies of analysis, taking into consideration the main control variables bearing a correlation with nPNA and/or RKF.

RESULTS

Mean nPNA (first 4 months) was 1.23 ± 0.33 g/kg/day, while the overall rate of decline of RKF was -0.13 ± 0.29 mL/min/month; 69 patients (25.1%) had lost >50% of their initial RKF by the end of the first year. Univariate analysis disclosed consistent associations between the main study variable on one hand and baseline RKF (r = 0.32, P < 0.0005) and its rate of decline (r = -0.23, P < 0.0005) on the other. The latter two variables were also significantly correlated (r = -0.36, P < 0.0005). Multivariate analysis identified mean nPNA as an independent predictor of the rate of decline of RKF [odds ratio 1.09 per 0.10 g/kg/day, 95% confidence interval (CI) 0.99-1.19, P = 0.058] and, in particular, of the probability of losing >50% of the baseline RKF during the first year of treatment (odds ratio 1.15 per 0.10 g/kg/day, 95% CI 1.04-1.27, P = 0.006).

CONCLUSION

Higher rates of PI during the first months of therapy are associated with a faster decline of RKF among patients incident on PD. Our results underline the convenience of keeping an adequate balance between sufficient protein ingestion, to prevent malnutrition and wasting, and sensible restriction in stable, adequately nourished individuals with rates of intake in the higher range or above-recommended allowances.

Risk Factors Before Dialysis Predominate as Mortality Predictors in Diabetic Maintenance Dialysis patients

Diabetic patients undergoing maintenance dialysis (MD) have a particularly high mortality rate. Many of the risk factors for mortality have been identified in diabetics who die before reaching end stage renal disease (ESRD), i.e. before dialysis (BD). In addition, many risk factors for mortality have been identified in diabetics after dialysis onset (AD). However, whether in the BD period there are long-term risk factors for AD mortality in diabetics is unknown. We therefore investigated a new concept, i.e. that clinical and biochemical risk factors during the BD stage affect long-term AD mortality. We performed a population based retrospective cohort study, in diabetic CKD patients in a single center in south Israel who initiated MD between the years 2003 and 2015. Clinical and biochemical data 12 months BD and 6 months AD were collected and evaluated for association with mortality AD using Cox’s proportional-hazards model. BD parameters that were found to be significant were adjusted for significant parameters AD, thus generating a “combined” regression model in order to isolate the contribution of BD factors on long term mortality. Six hundred and fifty two diabetic MD patients were included in the final analysis. Four independent BD parameters were found in the multivariate model to significantly predict AD mortality: age, BMI (inversely), pulse pressure (U-shaped) and cardiovascular comorbidity. AD independent risk factors for mortality were age, BMI (inversely) and albumin (inversely). Of note, BD factors remained dominantly significant even after additionally adjusting for AD factors. No association was found between either BD HbA1C levels or BD proteinuria and AD mortality. In diabetics who reach ESRD, BD parameters can predict long term AD mortality. Thus, some of the factors affecting the poor survival of diabetic MD patients appear to begin already in the BD period.

Dietary Care for ADPKD Patients: Current Status and Future Directions

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic nephropathy, and tolvaptan is the only therapy available. However, tolvaptan slows but does not stop disease progression, is marred by polyuria, and most patients worldwide lack access. This and recent preclinical research findings on the glucose-dependency of cyst-lining cells have renewed interest in the dietary management of ADPKD. We now review the current dietary recommendations for ADPKD patients according to clinical guidelines, the evidence base for those, and the potential impact of preclinical studies addressing the impact of diet on ADPKD progression. The clinical efficacy of tolvaptan has put the focus on water intake and solute ingestion as modifiable factors that may impact tolvaptan tolerance and ADPKD progression. By contrast, dietary modifications suggested to ADPKD patients, such as avoiding caffeine, are not well supported and their impact is unknown. Recent studies have identified a chronic shift in energy production from mitochondrial oxidative phosphorylation to aerobic glycolysis (Warburg effect) as a contributor to cyst growth, rendering cyst cells exquisitely sensitive to glucose availability. Therefore, low calorie or ketogenic diets have delayed preclinical ADPKD progression. Additional preclinical data warn of potential negative impact of excess dietary phosphate or oxalate in ADPKD progression.

Comparison of Shear Wave Elastography and Conventional Ultrasound in Assessing Kidney Function as Measured Using 51Cr-ethylenediaminetetraacetic Acid and 99Tc-Dimercaptosuccinic Acid

The purpose of this study was to assess the potential of shear wave elastography (SWE) as an indicator of abnormal kidney function defined by radiolabeled glomerular filtration rate (GFR). Fifty-seven patients referred for ⁵¹Cr-ethylenediaminetetraacetic acid GFR and ^99mTc-dimercaptosuccinic acid renal scintigraphy were included. Young's modulus (YM) measured with SWE and kidney length, volume, cortical thickness and parenchymal echogenicity measured with conventional ultrasound were correlated with patients' GFR and renal scintigraphy results. Spearman correlation coefficients between SWE and GFR were negative for the right (r = -0.635, p < 0.0001) and left (r = -0.817, p < 0.0001) kidneys. Positive correlations between left renal cortical thickness (r = 0.381, p = 0.04) and left kidney volume (r = 0.356, p = 0.019) with GFR were reported. SWE correctly predicted the dominant functioning kidney in 94.7% of cases. The area under the receiver operating characteristic curve for SWE (0.800) was superior to that for conventional ultrasound (0.252-0.415). The cutoff value of ≥5.52 kPa suggested a kidney function ≤60 mL/min/1.73 m² (82.4% sensitivity and 76.2% specificity). SWE has advantages over conventional ultrasound in assessing kidney function and distinguishing the dominant functioning kidney.

Role of Ultrasound in the Diagnosis of Chronic Kidney Disease and its Correlation with Serum Creatinine Level

Objective: We aimed to study the role of ultrasound in the diagnosis of chronic kidney disease (CKD) and its correlation with serum creatinine level.

Materials and methods: This was a retrospective cross sectional study conducted in the ultrasound department of Dr. Ziauddin Hospital Clifton campus, Karachi from April 6, 2017 to October 6, 2017 for a period of six months. A total of 200 patients with CKD and glomerular filtration rate (GFR) determined to be < 60 ml/min were included in this study. Blood tests were gathered from the chosen patients, serum creatinine estimation was done for those patients and they underwent ultrasonography on the same day to assess echogenicity, parenchymal thickness, cortical thickness, and longitudinal length. This information was noted in the pro forma.

Results: The average age of the patients was 54.62±13.3 years. Mean serum creatinine was significant among echogenicity grades [p=0.0005]. Mean parenchymal thickness was also significant among echogenicity grades (p=0.0005). Mean longitudinal length was also significant among echogenicity grades (p=0.0005). Mean corticomedullary distinction was also significant among echogenicity grades (p=0.0005). A statistically significant highly positive correlation was observed between serum creatinine and cortical echogenicity grading (r=0.915 P = 0.0005).

Conclusion: The best sonographic parameter that correlates with serum creatinine is renal cortical echogenicity and its grading in comparison to longitudinal length, parenchymal thickness, and cortical thickness in patients of CKD. Since renal cortical echogenicity has the advantage of being irreversible in comparison to serum creatinine levels, it can be used as a parameter of renal function.

Prevalence of Chronic Kidney Disease in Morbidly Obese Japanese and the Impact of Bariatric Surgery on Disease Progression

BACKGROUND

The prevalence of chronic kidney disease (CKD) among Japanese morbidly obese patients undergoing bariatric surgery and the impact of bariatric surgery on their renal function has not previously been investigated.

OBJECTIVES

The aims were to assess the prevalence of CKD patients who underwent bariatric surgery in our institution and to elucidate the impact of bariatric surgery on their kidney function as measured by the estimated glomerular filtration rate by Cystatin-C (eGFRcys).

SETTING

The setting of the study was in a single private hospital.

METHODS

Two hundred fifty-four consecutive Japanese patients who underwent bariatric surgery were retrospectively analyzed to elucidate the prevalence of CKD. The eGFRcys was calculated to assess the change in the kidney function for 1 year after surgery.

RESULTS

The preoperative prevalence of CKD was as follows: G1, 45.3%; G2, 47.2%; G3, 6.5%; and G4, 0.9%. The eGFRcys values before and after surgery were compared; the G1 and G2 patients showed significantly improved eGFRcys values after surgery (G1 101 [94-108] vs 114 [103-127]; G2 79 [74-84] vs 97 [87-104] ml/min/1.73 m²; p < 0.01) with significant weight loss (G1 38.1 ± 6.2 vs 26.5 ± 3.4; G2 38.5 ± 6.9 vs 26.7 ± 3.6 kg/m²; p < 0.01). Although the renal function of G3 patients was not improved after surgery (44 [42-47] vs 45 [43-63] ml/min/1.73 m²; p = 0.08), successful weight loss was achieved (36.1 ± 6.3 vs 26.6 ± 3.6 kg/m²; p < 0.01). In multivariate analysis, postoperative eGFRcys correlated negatively with proteinuria (p < 0.01), age (p < 0.01), and body mass index (p < 0.01) and positively with persistence of antihypertensive drugs.

CONCLUSION

Bariatric surgery resulted in the significant improvement in the eGFRcys values of Japanese patients with morbid obesity, particularly those with pre-CKD (eGFRcys ≥ 60 ml/min/1.73 m²), while the eGFRcys values of CKD patients (< 60 ml/min/1.73 m²) were not ameliorated by surgery.

Pharmacologic Renal Therapy

This article discusses some of the recommended pharmacologic treatments for patients with renal drug toxicity, acute kidney injury (AKI), and chronic kidney injury (CKI). The treatment of AKI often consists of treating patients in emergency departments. Renal pharmacologic management in an acute care setting consists of identifying the cause of AKI, reviewing serum creatinine levels, administration of crystalloids, and the elimination of nephrotoxic agents.