Metabolic acidosis is undertreated and underdiagnosed: a retrospective cohort study.

BACKGROUND: Guidelines recommend treatment of metabolic acidosis (MA) in patients with chronic kidney disease (CKD), but the diagnosis and treatment rates in real-world settings are unknown. We investigated the frequency of MA treatment and diagnosis in patients with CKD. METHODS: In this retrospective cohort study, we examined administrative health data from two US databases [Optum's de-identified Integrated Claims + Clinical Electronic Health Record Database (US EMR cohort; 1 January 2007 to 30 June 2019) and Symphony Health Solutions IDV® (US claims cohort; 1 May 2016 to 30 April 2019)] and population-level databases from Manitoba, Canada (1 April 2006 to 31 March 2018). Patients who met laboratory criteria indicative of CKD and chronic MA were included: two consecutive estimated glomerular filtration results <60 mL/min/1.73 m2 and two serum bicarbonate results 12 to <22 mEq/L over 28-365 days. Outcomes included treatment of MA (defined as a prescription for oral sodium bicarbonate) and a diagnosis of MA (defined using administrative records). Outcomes were assessed over a 3-year period (1 year pre-index, 2 years post-index). RESULTS: A total of 96 184 patients were included: US EMR, 6179; Manitoba, 3223; US Claims, 86 782. Sodium bicarbonate treatment was prescribed for 17.6%, 8.7% and 15.3% of patients, and a diagnosis was found for 44.7%, 20.9% and 20.9% of patients, for the US EMR, Manitoba and US Claims cohorts, respectively. CONCLUSIONS: This analysis of 96 184 patients with laboratory-confirmed MA from three independent cohorts of patients with CKD and MA highlights an important diagnosis and treatment gap for this disease-modifying complication.

The association between dual RAAS inhibition and risk of acute kidney injury and hyperkalemia in patients with diabetic kidney disease: a systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: Dual renin-angiotensin-aldosterone system (RAAS) blockade involves dual therapy with a combination of angiotensin-converting enzyme inhibitors (ACEis), angiotensin-receptor blockers (ARBs), direct renin inhibitors (DRIs), or mineralocorticoid receptor antagonists (MRAs). It is hypothesized that dual RAAS blockade would result in a more complete inhibition of the RAAS cascade. However, large clinical trials on dual RAAS inhibition have shown increased risk of acute kidney injury (AKI) and hyperkalemia without additional benefit on mortality, cardiovascular events, or chronic kidney disease (CKD) progression compared to RAAS inhibitor monotherapy in patients with diabetic kidney disease (DKD). The development of newer, more selective non-steroidal MRAs as cardiorenal protective therapies has created a new opportunity for dual RAAS inhibition. We conducted a systematic review and meta-analysis of the risks of AKI and hyperkalemia with dual RAAS blockade in patients with DKD. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: This is a systematic review and meta-analysis of the randomized controlled trials (RCT) published from 1 January 2006 to 30 May 2022. The study population included adult patients with DKD receiving dual RAAS blockade. A total of 31 RCTs and 33 048 patients were included in the systematic review. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using random effects. RESULTS: There were 208 AKI events in 2690 patients on ACEi + ARB versus 170 in 4264 patients with ACEi or ARB monotherapy (pooled RR 1.48, 95% CI: 1.23-1.39). There were 304 hyperkalemia events in 2818 patients on ACEi + ARB versus 208 in 4396 patients with ACEi or ARB monotherapy (pooled RR 1.97, 95% CI: 1.32-2.94). A non-steroidal MRA + ACEi or ARB showed no increase in the risk of AKI (pooled RR 0.97, 95% CI: 0.81-1.16) compared to ACEi or ARB monotherapy but had a 2-fold higher risk of hyperkalemia with 953 events in 7837 patients in dual therapy versus 454 events in 6895 patients in monotherapy (pooled RR 2.05, 95% CI: 1.84-2.28). A steroidal MRA + ACEi or ARB had a 5-fold higher risk of hyperkalemia with 28 events in 245 at risk in dual therapy versus five events in 248 at risk in monotherapy (pooled RR 5.42 95% CI: 2.15-13.67). CONCLUSION: Dual therapy with RAASi is associated with an increased risk of AKI and hyperkalemia compared to RAASi monotherapy. Conversely, dual therapy with RAAS inhibitors and non-steroidal MRAs have no additional risk of AKI but a similar risk of hyperkalemia, which is lower than dual therapy with RAAS inhibitors and steroidal MRAs.

Hyperkalemia-Related Discontinuation of Renin-Angiotensin-Aldosterone System Inhibitors and Clinical Outcomes in CKD: A Population-Based Cohort Study.

RATIONALE & OBJECTIVE: Renin-angiotensin-aldosterone system (RAAS) inhibitors are evidence-based therapies that slow the progression of chronic kidney disease (CKD) but can cause hyperkalemia. We aimed to evaluate the association of discontinuing RAAS inhibitors after an episode of hyperkalemia and clinical outcomes in patients with CKD. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adults in Manitoba (7,200) and Ontario (n = 71,290), Canada, with an episode of de novo RAAS inhibitor-related hyperkalemia (serum potassium ≥ 5.5 mmol/L) and CKD. EXPOSURE: RAAS inhibitor prescription. OUTCOME: The primary outcome was all-cause mortality. Secondary outcomes were cardiovascular (CV) mortality, fatal and nonfatal CV events, dialysis initiation, and a negative control outcome (cataract surgery). ANALYTICAL APPROACH: Cox proportional hazards models examined the association of RAAS inhibitor continuation (vs discontinuation) and outcomes using intention to treat approach. Sensitivity analyses included time-dependent, dose-dependent, and propensity-matched analyses. RESULTS: The mean potassium and mean estimated glomerular filtration rate were 5.8 mEq/L and 41 mL/min/1.73 m2, respectively, in Manitoba; and 5.7 mEq/L and 41 mL/min/1.73 m2, respectively, in Ontario. RAAS inhibitor discontinuation was associated with a higher risk of all-cause mortality (Manitoba: HR, 1.32 [95% CI, 1.22-1.41]; Ontario: HR, 1.47 [95% CI, 1.41-1.52]) and CV mortality (Manitoba: HR, 1.28 [95% CI, 1.13-1.44]; and Ontario: HR, 1.32 [95% CI, 1.25-1.39]). RAAS inhibitor discontinuation was associated with an increased risk of dialysis initiation in both cohorts (Manitoba: HR, 1.65 [95% CI, 1.41-1.85]; Ontario: HR, 1.11 [95% CI, 1.08-1.16]). LIMITATIONS: Retrospective study and residual confounding. CONCLUSIONS: RAAS inhibitor discontinuation is associated with higher mortality and CV events compared with continuation among patients with hyperkalemia and CKD. Strategies to maintain RAAS inhibitor treatment after an episode of hyperkalemia may improve clinical outcomes in the CKD population.

Effects of a Knowledge-Translation Intervention on Early Dialysis Initiation: A Cluster Randomized Trial.

BACKGROUND: The Initiating Dialysis Early and Late (IDEAL) trial, published in 2009, found no clinically measurable benefit with respect to risk of mortality or early complications with early dialysis initiation versus deferred dialysis start. After these findings, guidelines recommended an intent-to-defer approach to dialysis initiation, with the goal of deferring it until clinical symptoms arise. METHODS: To evaluate a four-component knowledge translation intervention aimed at promoting an intent-to-defer strategy for dialysis initiation, we conducted a cluster randomized trial in Canada between October 2014 and November 2015. We randomized 55 clinics, 27 to the intervention group and 28 to the control group. The educational intervention, using knowledge-translation tools, included telephone surveys from a knowledge-translation broker, a 1-year center-specific audit with feedback, delivery of a guidelines package, and an academic detailing visit. Participants included adults who had at least 3 months of predialysis care and who started dialysis in the first year after the intervention. The primary efficacy outcome was the proportion of patients who initiated dialysis early (at eGFR >10.5 ml/min per 1.73 m2). The secondary outcome was the proportion of patients who initiated in the acute inpatient setting. RESULTS: The analysis included 3424 patients initiating dialysis in the 1-year follow-up period. Of these, 509 of 1592 (32.0%) in the intervention arm and 605 of 1832 (33.0%) in the control arm started dialysis early. There was no difference in the proportion of individuals initiating dialysis early or in the proportion of individuals initiating dialysis as an acute inpatient. CONCLUSIONS: A multifaceted knowledge translation intervention failed to reduce the proportion of early dialysis starts in patients with CKD followed in multidisciplinary clinics. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: ClinicalTrials.gov, NCT02183987. Available at: https://clinicaltrials.gov/ct2/show/NCT02183987.

Opioids and the Risk of Motor Vehicle Collision: A Systematic Review.

Background: Opioid analgesics are among the most commonly prescribed medications, but questions remain regarding their impact on the day-to-day functioning of patients including driving. We set out to perform a systematic review on the risk of motor vehicle collision (MVC) associated with prescription opioid exposure. Method: We searched Medline, PubMed, EMBASE, Scopus, and TRID from January 1990 to August 31, 2021 for primary studies assessing prescribed opioid use and MVCs. Results: We identified 14 observational studies that met inclusion criteria. Among those, 8 studies found an increased risk of MVC among those participants who had a concomitant opioid prescription at the time of the MVC and 3 found no significant increase of culpability of fatal MVC. The 3 studies that evaluated the presence of a dose-response relationship between the dose of opioids taken and the effects on MVC risk reported the existence of a dose-response relationship. Due to the heterogeneity of the different studies, a quantitative meta-analysis to sum evidence was deemed unfeasible. Our review supports increasing evidence on the association between motor vehicle collisions and prescribed opioids. This research would guide policies regarding driving legislation worldwide. Conclusion: Our review indicates that opioid prescriptions are likely associated with an increased risk of MVCs. Further studies are warranted to strengthen this finding, and investigate additional factors such as individual opioid medications, opioid doses and dose adjustments, and opioid tolerance for their effect on MVC risk.

Association of Physical Activity and Poor Health Outcomes in Patients With Advanced CKD.

RATIONALE & OBJECTIVE: Chronic kidney disease (CKD) is associated with declining physical function and activity. In the general population, lower physical activity is associated with poorer quality of life and greater all-cause mortality. The aim of this study was to assess if lower physical activity levels are associated with adverse health outcomes in patients with advanced CKD. STUDY DESIGN: A multicenter prospective cohort study. SETTING & PARTICIPANTS: 579 adult patients with CKD glomerular filtration rate categories 4 and 5 (G4-G5) treated at 4 Canadian multidisciplinary kidney health clinics between 2012 and 2018. EXPOSURE: Patient-reported measures of physical activity using the Physical Activity Scale for the Elderly (PASE) questionnaire and subsequently stratified PASE scores into tertiles. OUTCOME: All-cause mortality, progression to kidney failure, and future falls. ANALYTICAL APPROACH: Outcomes were analyzed using time-dependent proportional hazards models and logistic regression models. RESULTS: In 1,193 days of follow-up observation, 118 patients died, 204 progressed to dialysis, and 129 reported a fall. When compared with low physical activity, higher levels of physical activity were associated with a 52% lower all-cause mortality (adjusted HR, 0.48; 95% CI, 0.27-0.85) in models adjusted for age, sex, and comorbidity. No associations were detected between higher levels of physical activity and either slower progression to kidney failure or a lower rate of future falls. LIMITATIONS: Physical activity and falls were self-reported. Our population was of limited racial/ethnic diversity, which may affect generalizability. Findings were observational and do not indicate whether interventions targeting physical activity may affect adverse health outcomes. CONCLUSIONS: Higher levels of physical activity were associated with about 50% lower all-cause mortality in the advanced CKD population. These findings are consistent with a potential benefit from maintained physical activity as patients approach kidney failure.

Impact of point-of-care screening for hypertension, diabetes and progression of chronic kidney disease in rural Manitoba Indigenous communities.

BACKGROUND: In 2013-2015, we conducted point-of-care screening for hypertension, diabetes and chronic kidney disease in rural and remote Indigenous communities in Manitoba, Canada. In this study, we aimed to determine whether optimal follow-up care was provided, defined as proportion of individuals with appropriate kidney disease laboratory testing, medication prescriptions and physician visits. METHODS: We linked screening data from participants to provincial administrative data sets to evaluate whether frequencies of laboratory testing, prescriptions of disease-modifying medications, and primary care and nephrology visits differed in the 18 months before and after screening. We also conducted a propensity score matching analysis to compare outcomes between screened and unscreened adults. RESULTS: Of 1353 adults who received the screening intervention and who had complete administrative data available, 44% were at risk of kidney failure at screening. Among these individuals, frequencies of comprehensive laboratory testing (estimated glomerular filtration rate and urine albumin to creatinine ratio) improved by 17.0% (95% confidence interval [CI] 11.5 to 22.5), anti-hyperglycemic medications improved by 4.4% (95% CI 1.0 to 7.8), and nephrology visits for participants meeting referral criteria improved by 5.9% (95% CI 3.4 to 8.5). We observed significant improvements in laboratory testing, antihyperglycemic medications and nephrology visits in the screened group compared with the 1:1 matched comparison group. INTERPRETATION: Point-of-care screening programs in rural and remote Indigenous communities are adaptable methods for increasing awareness, monitoring risk and treating chronic diseases. Interventions such as the development of a national screening program could improve chronic disease care in high-risk populations.

Recent advances in the treatment of uremic pruritus.

PURPOSE OF REVIEW: This article provides a focused update on uremic pruritus, highlighting the latest evidence concerning the epidemiology, pathophysiology, and treatment options for this common and bothersome condition. RECENT FINDINGS: Half of dialysis patients and a quarter of those with nondialysis chronic kidney disease experience bothersome itch that reduces quality of life and is increasingly recognized to be associated with poor outcomes including mortality. The KALM-1 trial, which reported effective symptomatic relief with difelikefalin, has bolstered support for the role of an imbalance of µ and κ-opioid receptor activity in pruritogenesis. The role of a chronic inflammatory state, increased cytokine levels and altered immune signaling in pruritogenic nerve activation continues to be elucidated with basic science, which paves the wave for future novel therapeutics. In the meantime, gabapentin appears to be the most evidence-based widely available uremic pruritus treatment, as long as care is taken with dosing and monitoring of side-effects. SUMMARY: Uremic pruritus remains a top research priority. Patients with uremic pruritus may be able to look forward to a new decade of understanding, knowledge, and novel treatment options for this burdensome condition. As difelikefalin and other potential agents come to market, cost-effectiveness assessments of these interventions will help determine if the widespread use of them is feasible amongst renal programs.

Acute Kidney Injury Events in Patients With Type 2 Diabetes Using SGLT2 Inhibitors Versus Other Glucose-Lowering Drugs: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: Sodium/glucose cotransporter 2 (SGLT2) inhibitors slow the progression of chronic kidney disease and prevent heart failure events. However, SGLT2 inhibitors may increase the risk for acute kidney injury (AKI). Our objective was to assess whether SGLT2 inhibitor use, compared with all other glucose-lowering drugs (oGLDs), is associated with increased rates of AKI. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adults in Manitoba, Canada, with type 2 diabetes mellitus followed up from June 2014 until March 2017. EXPOSURES: Initial SGLT2 inhibitor or oGLD use ascertained through a province-wide outpatient prescription database. OUTCOME: The primary outcome was incident AKI, identified either by an increase in serum creatinine level and/or hospital discharge codes for AKI while taking glucose-lowering drugs (on-treatment approach). ANALYTICAL APPROACH: A propensity score analysis was used to assemble groups of incident users of SGLT2 inhibitors and a 1:1 matched set of oGLD users. The rate of AKI was compared across matched groups using cause-specific hazards models. Sensitivity analyses considered exposure to be constant throughout follow-up after initiation of the drug treatment (intention-to-treat approach) or incorporated recurrent exposures (new user design). RESULTS: Comparing 4,778 incident users of SGLT2 inhibitors with 4,778 incident users of oGLDs, there were no differences observed in the primary outcome (HR, 0.64; 95% CI, 0.40-1.03; P = 0.06) using an on-treatment approach. In neither set of sensitivity analyses were SGLT2 inhibitors associated with increased risk for AKI. LIMITATIONS: Drug choice may have been related to AKI risk, laboratory data were obtained from clinical care, and changes in adverse event reporting may have followed the US Food and Drug Administration warning. There were insufficient data to compare individual SGLT2 inhibitors. CONCLUSIONS: Compared with oGLDs, SGLT2 inhibitors were not observed to be associated with increased risk for AKI in a clinical population-based cohort.

Peripheral Artery Disease: Its Adverse Consequences With and Without CKD.

RATIONALE & OBJECTIVES: Chronic kidney disease (CKD) is a potent risk factor for macrovascular disease and death. Peripheral artery disease (PAD) is more common in patients with CKD and is associated with lower-limb complications and mortality. We sought to compare the prevalence of PAD in and outside the setting of kidney disease and examine how PAD affects the risk for adverse health outcomes, specifically lower-limb complications, cardiovascular events, and survival. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: 453,573 adult residents of Manitoba with at least 1 serum creatinine measurement between 2007 and 2014. EXPOSURE: PAD defined by hospital discharge diagnosis codes and medical claims. OUTCOMES: All-cause mortality, cardiovascular events, and lower-limb complications, including foot ulcers and nontraumatic amputations. ANALYTICAL APPROACH: Survival analysis using Cox proportional hazards models. RESULTS: The prevalence of PAD in our study population was 4.5%, and patients with PAD were older, were more likely to be male, and had a higher burden of comorbid conditions, including diabetes and CKD. PAD was associated with higher risks for all-cause mortality, cardiovascular events, and lower-limb complications in patients with estimated glomerular filtration rate (eGFR) ≥ 60mL/min/1.73m2, those with CKD GFR categories 3 to 5 (G3-G5), and those treated by dialysis (CKD G5D). Although HRs for PAD were lower in the CKD population, event rates were higher as compared with those with eGFR≥60mL/min/1.73m2. In particular, compared with patients with eGFR≥60mL/min/1.73m2 and without PAD, patients with CKD G5D had 10- and 12-fold higher risks for lower-limb complications, respectively (adjusted HRs of 10.36 [95% CI, 8.83-12.16] and 12.02 [95% CI, 9.58-15.08] for those without and with PAD, respectively), and an event rate of 75/1,000 patient-years. LIMITATIONS: Potential undercounting of PAD and complications using administrative codes and the limited ability to examine quality-of-care indicators for PAD. CONCLUSIONS: PAD is more common in patients with CKD G3-G5 and G5D compared with those with eGFR≥60mL/min/1.73m2 and frequently leads to lower-limb complications. Medical interventions and care pathways specifically designed to slow or prevent the development of lower-limb complications in this population are urgently needed.

The Fracture Risk Assessment Tool (FRAX®) predicts fracture risk in patients with chronic kidney disease.

The Fracture Risk Assessment Tool (FRAX®) was developed to predict fracture risk in the general population, but its applicability to patients with chronic kidney disease (CKD) is unknown. Using the Manitoba Bone Mineral Density (BMD) Database, we identified adults not receiving dialysis with available serum creatinine measurements and bone densitometry within 1 year. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Incident major osteoporotic fractures and hip fractures were ascertained from population-based health care databases. The performance of FRAX, derived without and with BMD, was studied in relation to CKD stage. Among 10,099 subjects (mean age 64 ± 13 years, 13.0% male), 2,154 had eGFR 30-60 mL/min/1.73 m2 (CKD stage 3) and 590 had eGFR <30 mL/min/1.73 m2 (CKD stages 4-5). During a 5-year observation period, 772 individuals experienced a major osteoporotic fracture and 226 had a hip fracture. FRAX predicted risk for major osteoporotic fracture and hip fracture in all eGFR strata. For every standard deviation increase in FRAX score derived with BMD, the hazard ratio (HR) for hip fracture was 4.54 (95% confidence interval [CI] 3.57-5.77) in individuals with eGFR ≥ 60 mL/min/1.73m2, 4.52 (95% CI 3.15-6.49) in individuals with eGFR 30-60 mL/min/1.73m2, and 3.10 (95% CI 1.80-5.33) in individuals with eGFR <30 mL/min/1.73m2. The relationship between FRAX and major osteoporotic fracture was stronger in those with CKD compared to those with preserved eGFR. These findings support the use of FRAX to risk stratify patients with non-dialysis CKD for major osteoporotic fractures and hip fractures.

Activity-Based Protein Profiling of Intraoperative Serine Hydrolase Activities during Cardiac Surgery.

The processes involved in the initiation of acute kidney injury (AKI) following cardiopulmonary bypass (CPB) are thought to occur during the intraoperative period. Such a rapid development might indicate that some of the inductive events are not dependent on de novo protein synthesis, raising the possibility that changes in activities of pre-existing enzymes could contribute to the development of AKI. Activity-based protein profiling (ABPP) was used to compare the serine hydrolase enzyme activities present in the urines of CPB patients who subsequently developed AKI versus those who did not (non-AKI) during the intra- and immediate postoperative periods. Sequential urines collected from a nested case-control cohort of AKI and non-AKI patients were reacted with a serine hydrolase activity probe, fluorophosphonate-TAMRA, and separated by SDS-PAGE. The patterns and levels of probe-labeled proteins in the two groups were initially comparable. However, within 1 h of CPB there were significant pattern changes in the AKI group. Affinity purification and mass spectrometry-based analysis of probe-labeled enzymes in AKI urines at 1 h CPB and arrival to the intensive care unit (ICU) identified 28 enzymes. Quantitative analysis of the activity of one of the identified enzymes, kallikrein-1, revealed some trends suggesting differences in the levels and temporal patterns of enzyme activity between a subset of patients who developed AKI and those who did not. A comparative analysis of affinity-purified probe reacted urinary proteins from these patient groups during the intraoperative period suggested the presence of both shared and unique enzyme patterns. These results indicate that there are intraoperative changes in the levels and types of serine hydrolase activities in patients who subsequently develop AKI. However, the role of these activity differences in the development of AKI remains to be determined.

CKD and Sedentary Time: Results From the Canadian Health Measures Survey.

RATIONALE & OBJECTIVE: Sedentary behavior and low physical activity are associated with incident diabetes, cardiovascular disease, and early mortality. Previous studies have examined associations between chronic kidney disease (CKD) and physical activity, but little is known about the role of sedentary time. STUDY DESIGN: Cross-sectional national survey. SETTING & PARTICIPANTS: A nationally representative sample of adults (n=8,444) participating in the Canadian Health Measures Survey's (CHMS) activity monitoring component (2007-2013). PREDICTOR: Estimated glomerular filtration rate (eGFR). OUTCOMES: Sedentary time (total sedentary minutes/total wear time) measured using triaxial accelerometry. ANALYTICAL APPROACH: Multivariable ordinal logistic regression for quartiles of sedentary time and linear regression for sedentary time measured on a continuous scale were performed in the entire study population and in the subgroup with CKD. RESULTS: Mean proportion of sedentary time ranged from 58% (least sedentary quartile: Q1) to 81% (most sedentary quartile: Q4). Lower eGFR, older age, lower serum albumin level, higher blood pressure, cardiovascular disease, diabetes, and higher body mass index were independently associated with a higher proportion of sedentary time. Patients with eGFRs < 45mL/min/1.73m2 had more than 4-fold higher likelihood of being sedentary (OR, 4.2; 95% CI, 2.5-7.3). Within the CKD subgroup, greater sedentary time was associated with diabetes (OR, 2.68; 95% CI, 1.56-4.59) and arthritis (OR, 2.32; 95% CI, 1.43-3.77) in adjusted analysis. LIMITATIONS: Cross-sectional design precluded evaluation of longitudinal outcomes and establishment of the causal nature of observed associations. Small sample of individuals with advanced CKD. CONCLUSIONS: In this cross-sectional survey, reduced eGFR was strongly and independently associated with greater sedentary time. This risk was further heightened by the presence of diabetes and arthritis. Studies to determine causes for sedentary behavior and assess the feasibility and value of interventions to reduce sedentary time in CKD are needed.

Screening for kidney disease in Indigenous Canadian children: The FINISHED screen, triage and treat program.

BACKGROUND: Indigenous populations are disproportionately affected by kidney failure at younger ages than other ethnic groups in Canada. As symptoms do not occur until disease is advanced, early kidney disease risk is often unrecognized. OBJECTIVES: We sought to evaluate the yield of community-based screening for early risk factors for kidney disease in youth from rural Indigenous communities in Canada. METHODS: The FINISHED project screened 11 rural First Nations communities in Manitoba, Canada after community and school engagement. The results for the 10- to 17-year olds are reported here. Body mass index (BMI), blood pressure, estimated glomerular filtration rate (eGFR), hemoglobin A1c's (HbA1c) and urine albumin-to-creatinine ratios (ACR) were assessed. All children were triaged and referred to either primary or tertiary care, depending on risk. RESULTS: A total of 353 were screened (estimated 22.4% of population). The median age was 12 years (IQR 10 to 13), 55% were female and 55% were overweight or obese. Overall, 21.8% of children had at least one abnormality. Hypertension was identified in 5.4% and 11.9% had prehypertension. None of the children had an eGFR < 60 ml/min/1.73 m2 however 10.5% had an ACR > 3 mg/mmol and 6.2% had an eGFR < 90 ml/min/1.73 m2 suggestive of early kidney disease. Diabetes was identified in 1.4%, and 1.4% had HbA1c's between 6.1% and 6.49%. CONCLUSIONS: Risk factors for chronic kidney disease are highly prevalent in rural Indigenous children. More research is required to confirm the persistence of these findings, and to evaluate the efficacy of screening children to prevent or delay progression to kidney failure.

Screening for chronic kidney disease in Canadian indigenous peoples is cost-effective.

Canadian indigenous (First Nations) have rates of kidney failure that are 2- to 4-fold higher than the non-indigenous general Canadian population. As such, a strategy of targeted screening and treatment for CKD may be cost-effective in this population. Our objective was to assess the cost utility of screening and subsequent treatment for CKD in rural Canadian indigenous adults by both estimated glomerular filtration rate and the urine albumin-to-creatinine ratio. A decision analytic Markov model was constructed comparing the screening and treatment strategy to usual care. Primary outcomes were presented as incremental cost-effectiveness ratios (ICERs) presented as a cost per quality-adjusted life-year (QALY). Screening for CKD was associated with an ICER of $23,700/QALY in comparison to usual care. Restricting the model to screening in communities accessed only by air travel (CKD prevalence 34.4%), this ratio fell to $7,790/QALY. In road accessible communities (CKD prevalence 17.6%) the ICER was $52,480/QALY. The model was robust to changes in influential variables when tested in univariate sensitivity analyses. Probabilistic sensitivity analysis found 72% of simulations to be cost-effective at a $50,000/QALY threshold and 93% of simulations to be cost-effective at a $100,000/QALY threshold. Thus, targeted screening and treatment for CKD using point-of-care testing equipment in rural Canadian indigenous populations is cost-effective, particularly in remote air access-only communities with the highest risk of CKD and kidney failure. Evaluation of targeted screening initiatives with cluster randomized controlled trials and integration of screening into routine clinical visits in communities with the highest risk is recommended.

Anemia management in chronic kidney disease and dialysis: a narrative review.

PURPOSE OF REVIEW: This review describes the current state of anemia management with erythropoietin (EPO)-stimulating agents and iron supplementation in both chronic kidney disease and dialysis patients, with a focus on novel therapies. RECENT FINDINGS: We review the benefits and risks of EPO-stimulating agents, focusing on health-related quality of life and the uncertainties regarding optimal iron utilization in patients with kidney disease. We discuss novel therapies for iron supplementation including iron-based phosphate binders and dialysate iron delivery as well as alternatives to EPO-stimulating agents including hypoxia-inducible factor prolyl hydroxylase inhibitors. SUMMARY: Individualization of hemoglobin targets using EPO-stimulating agents and iron supplementation may be considered in younger, healthier patients with kidney disease to improve health-related quality of life. Optimal iron utilization in kidney disease patients is unclear, but novel iron base phosphate binders and dialysate iron delivery may play a role in intravenous iron avoidance and its potential complications. Phase 3 randomized controlled trials of hypoxia-inducible factor prolyl hydroxylase inhibitors are ongoing and are promising new alternatives to EPO-stimulating agents and their known adverse effects.

Treatment of Uremic Pruritus: A Systematic Review.

BACKGROUND: Uremic pruritus is a common and burdensome symptom afflicting patients with advanced chronic kidney disease (CKD) and has been declared a priority for CKD research by patients. The optimal treatments for uremic pruritus are not well defined. STUDY DESIGN: Systematic review. SETTING & POPULATION: Adult patients with advanced CKD (stage ≥ 3) or receiving any form of dialysis. SELECTION CRITERIA FOR STUDIES: PubMed, CINAHL, Embase, International Pharmaceutical Abstracts, Scopus, Cochrane Library, and ClinicalTrials.gov from their inception to March 6, 2017, were systematically searched for randomized controlled trials (RCTs) of uremic pruritus treatments in patients with advanced CKD (stage ≥ 3) or receiving any form of dialysis. 2 reviewers extracted data independently. Risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. INTERVENTION: Any intervention for the treatment of uremic pruritus was included. OUTCOMES: A quantitative change in pruritus intensity on a visual analogue, verbal rating, or numerical rating scale. RESULTS: 44 RCTs examining 39 different treatments were included in the review. These treatments included gabapentin, pregabalin, mast cell stabilizers, phototherapy, hemodialysis modifications, and multiple other systemic and topical treatments. The largest body of evidence was found for the effectiveness of gabapentin. Due to the limited number of trials for the other treatments included, we are unable to comment on their efficacy. Risk of bias in most studies was high. LIMITATIONS: Heterogeneity in design, treatments, and outcome measures rendered comparisons difficult and precluded meta-analysis. CONCLUSIONS: Despite the acknowledged importance of uremic pruritus to patients, with the exception of gabapentin, the current evidence for treatments is weak. Large, simple, rigorous, multiarm RCTs of promising therapies are urgently needed.

The Effect of Erythropoietin-Stimulating Agents on Health-Related Quality of Life in Anemia of Chronic Kidney Disease: A Systematic Review and Meta-analysis.

BACKGROUND: The efficacy of erythropoietin-stimulating agents (ESAs) for improving health-related quality of life (HRQOL) in anemia of chronic kidney disease (CKD) is unclear. PURPOSE: To determine the effect of ESAs on HRQOL at different hemoglobin targets in adults with CKD who were receiving or not receiving dialysis. DATA SOURCES: Searches of PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov from inception to 1 November 2015, supplemented with manual screening. STUDY SELECTION: Randomized, controlled trials that evaluated the treatment of anemia with ESAs, including erythropoietin and darbepoetin, targeted higher versus lower hemoglobin levels, and used validated HRQOL metrics. DATA EXTRACTION: Study characteristics, quality, and data were assessed independently by 2 reviewers. Outcome measures were scores on the Short Form-36 Health Survey (SF-36), Kidney Dialysis Questionnaire (KDQ), and other tools. DATA SYNTHESIS: Of 17 eligible studies, 13 reported SF-36 outcomes and 4 reported KDQ outcomes. Study populations consisted of patients not undergoing dialysis (n = 12), those undergoing dialysis (n = 4), or a mixed sample (n = 1). Only 4 studies had low risk of bias. Pooled analyses showed that higher hemoglobin targets resulted in no statistically or clinically significant differences in SF-36 or KDQ domains. Differences in HRQOL were further attenuated in studies at low risk of bias and in subgroups of dialysis recipients. LIMITATION: Statistically significant heterogeneity among studies, few good-quality studies, and possible publication bias. CONCLUSION: ESA treatment of anemia to obtain higher hemoglobin targets does not result in important differences in HRQOL in patients with CKD. PRIMARY FUNDING SOURCE: KRESCENT and Manitoba Health Research Council Establishment.

Lab-on-a-Chip Platforms for Detection of Cardiovascular Disease and Cancer Biomarkers.

Cardiovascular disease (CVD) and cancer are two leading causes of death worldwide. CVD and cancer share risk factors such as obesity and diabetes mellitus and have common diagnostic biomarkers such as interleukin-6 and C-reactive protein. Thus, timely and accurate diagnosis of these two correlated diseases is of high interest to both the research and healthcare communities. Most conventional methods for CVD and cancer biomarker detection such as microwell plate-based immunoassay and polymerase chain reaction often suffer from high costs, low test speeds, and complicated procedures. Recently, lab-on-a-chip (LoC)-based platforms have been increasingly developed for CVD and cancer biomarker sensing and analysis using various molecular and cell-based diagnostic biomarkers. These new platforms not only enable better sample preparation, chemical manipulation and reaction, high-throughput and portability, but also provide attractive features such as label-free detection and improved sensitivity due to the integration of various novel detection techniques. These features effectively improve the diagnostic test speed and simplify the detection procedure. In addition, microfluidic cell assays and organ-on-chip models offer new potential approaches for CVD and cancer diagnosis. Here we provide a mini-review focusing on recent development of LoC-based methods for CVD and cancer diagnostic biomarker measurements, and our perspectives of the challenges, opportunities and future directions.

Rapid and Low-Cost CRP Measurement by Integrating a Paper-Based Microfluidic Immunoassay with Smartphone (CRP-Chip).

Traditional diagnostic tests for chronic diseases are expensive and require a specialized laboratory, therefore limiting their use for point-of-care (PoC) testing. To address this gap, we developed a method for rapid and low-cost C-reactive protein (CRP) detection from blood by integrating a paper-based microfluidic immunoassay with a smartphone (CRP-Chip). We chose CRP for this initial development because it is a strong biomarker of prognosis in chronic heart and kidney disease. The microfluidic immunoassay is realized by lateral flow and gold nanoparticle-based colorimetric detection of the target protein. The test image signal is acquired and analyzed using a commercial smartphone with an attached microlens and a 3D-printed chip-phone interface. The CRP-Chip was validated for detecting CRP in blood samples from chronic kidney disease patients and healthy subjects. The linear detection range of the CRP-Chip is up to 2 µg/mL and the detection limit is 54 ng/mL. The CRP-Chip test result yields high reproducibility and is consistent with the standard ELISA kit. A single CRP-Chip can perform the test in triplicate on a single chip within 15 min for less than 50 US cents of material cost. This CRP-Chip with attractive features of low-cost, fast test speed, and integrated easy operation with smartphones has the potential to enable future clinical PoC chronic disease diagnosis and risk stratification by parallel measurements of a panel of protein biomarkers.