High volume online hemodiafiltration: a global perspective and the Brazilian experience / Hemodiafiltração on-line de alto volume: uma perspectiva global e a experiência brasileira

ABSTRACT Online hemodiafiltration (HDF) is a rapidly growing dialysis modality worldwide. In Brazil, the number of patients with private health insurance undergoing HDF has exceeded the number of patients on peritoneal dialysis. The achievement of a high convection volume was associated with better clinical imprand patient - reported outcomes confirming the benefits of HDF. The HDFit trial provided relevant practical information on the implementation of online HDF in dialysis centers in Brazil. This article aims to disseminate technical information to improve the quality and safety of this new dialysis modality.

RESUMO A hemodiafiltração (HDF) on-line é uma modalidade dialítica em rápido crescimento no mundo. No Brasil, o número de pacientes com planos de saúde privados tratados por HDF já ultrapassa aquele de pacientes em diálise peritoneal. O alcance de um alto volume convectivo associado à redução de desfechos clínicos e do risco de morte confirmam os benefícios da HDF. Dados nacionais do estudo HDFit forneceram informações práticas relevantes sobre a implementação da HDF on-line em clínicas de diálise no Brasil. O objetivo desta publicação é a disseminação de informações técnicas que possam auxiliar na utilização, com qualidade e segurança, dessa nova modalidade dialítica.

Efficacy and Safety of Dapagliflozin in Patients With Chronic Kidney Disease Across the Spectrum of Frailty.

BACKGROUND: A sizeable proportion of patients with chronic kidney disease (CKD) are reported to be frail. Here we examined the safety and efficacy of dapagliflozin in patients with CKD by frailty level. METHODS: Adults with CKD, with/without type 2 diabetes, with an estimated glomerular filtration rate (eGFR) of 25-75 mL/min/1.73 m2, and urinary albumin-to-creatinine ratio 200-5 000 mg/g were randomized to dapagliflozin (10 mg/day) or placebo. The primary endpoint was a composite of sustained ≥50% eGFR decline, end-stage kidney disease (ESKD), or death from kidney or cardiovascular (CV) causes. RESULTS: Frailty index (FI), assessed by Rockwood cumulative deficit approach, was calculable in 4 303/4 304 (99.9%) patients: 1 162 (27.0%) in not-to-mildly frail (FI ≤0.210), 1 642 (38.2%) in moderately frail (FI 0.211-0.310), and 1 499 (34.8%) in severely frail categories (FI >0.311). Dapagliflozin reduced the risk of the primary composite endpoint across all FI categories (hazard ratios [95% confidence interval {CI}]: 0.50 [0.33-0.76], 0.62 [0.45-0.85], and 0.64 [0.49--0.83], respectively; p-interaction = 0.67). Results were similar for secondary outcomes including kidney composite outcome (sustained ≥50% eGFR decline, ESKD or death from kidney cause; p-interaction = 0.44), CV endpoint (heart failure hospitalization or CV death; p-interaction = 0.63), and all-cause mortality (p-interaction p = .42). Results were consistent when using FI as a continuous variable. Occurrence of serious adverse events was numerically lower in patients receiving dapagliflozin versus placebo in all FI categories (16.9% vs 20.1%, 26.3% vs 30.7%, and 42.9% vs 47.8%, in not-to-mildly, moderately, and severely frail categories, respectively). CONCLUSIONS: The relative benefit of dapagliflozin for all outcomes was consistent across all frailty categories, with no difference in associated safety.

Unveiling the Clinical Benefits of High-Volume Hemodiafiltration: Optimizing the Removal of Medium-Weight Uremic Toxins and Beyond.

Dialysis treatment has improved the survival of patients with kidney failure. However, the hospitalization and mortality rates remain alarmingly high, primarily due to incomplete uremic toxin elimination. High-volume hemodiafiltration (HDF) has emerged as a promising approach that significantly improves patient outcomes by effectively eliminating medium and large uremic toxins, which explains its increasing adoption, particularly in Europe and Japan. Interest in this therapy has grown following the findings of the recently published CONVINCE study, as well as the need to understand the mechanisms behind the benefits. This comprehensive review aims to enhance the scientific understanding by explaining the underlying physiological mechanisms that contribute to the positive effects of HDF in terms of short-term benefits, like hemodynamic tolerance and cardiovascular disease. Additionally, it explores the rationale behind the medium-term clinical benefits, including phosphorus removal, the modulation of inflammation and oxidative stress, anemia management, immune response modulation, nutritional effects, the mitigation of bone disorders, neuropathy relief, and amyloidosis reduction. This review also analyzes the impact of HDF on patient-reported outcomes and mortality. Considering the importance of applying personalized uremic toxin removal strategies tailored to the unique needs of each patient, high-volume HDF appears to be the most effective treatment to date for patients with renal failure. This justifies the need to prioritize its application in clinical practice, initially focusing on the groups with the greatest potential benefits and subsequently extending its use to a larger number of patients.

International practice patterns of dyslipidemia management in patients with chronic kidney disease under nephrology care: is it time to review guideline recommendations?

BACKGROUND: In contrast to guidelines related to lipid therapy in other areas, 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend conducting a lipid profile upon diagnosis of chronic kidney disease (CKD) and treating all patients older than 50 years without defining a target for lipid levels. We evaluated multinational practice patterns for lipid management in patients with advanced CKD under nephrology care. METHODS: We analyzed lipid-lowering therapy (LLT), LDL- cholesterol (LDL-C) levels, and nephrologist-specified LDL-C goal upper limits in adult patients with eGFR < 60 ml/min from nephrology clinics in Brazil, France, Germany, and the United States (2014-2019). Models were adjusted for CKD stage, country, cardiovascular risk indicators, sex, and age. RESULTS: LLT treatment differed significantly by country, from 51% in Germany to 61% in the US and France (p = 0.002) for statin monotherapy. For ezetimibe with or without statins, the prevalence was 0.3% in Brazil to 9% in France (< 0.001). Compared with patients not taking lipid-lowering therapy, LDL-C was lower among treated patients (p < 0.0001) and differed significantly by country (p < 0.0001). At the patient level, the LDL-C levels and statin prescription did not vary significantly by CKD stage (p = 0.09 LDL-C and p = 0.24 statin use). Between 7-23% of untreated patients in each country had LDL-C ≥ 160 mg/dL. Only 7-17% of nephrologists believed that LDL-C should be < 70 mg/dL. CONCLUSION: There is substantial variation in practice patterns regarding LLT across countries but not across CKD stages. Treated patients appear to benefit from LDL-C lowering, yet a significant proportion of hyperlipidemia patients under nephrologist care are not receiving treatment.

CVOT Summit 2022 Report: new cardiovascular, kidney, and glycemic outcomes.

The 8th Cardiovascular Outcome Trial (CVOT) Summit on Cardiovascular, Kidney, and Glycemic Outcomes was held virtually on November 10-12, 2022. Following the tradition of previous summits, this reference congress served as a platform for in-depth discussion and exchange on recently completed outcomes trials as well as key trials important to the cardiovascular (CV) field. This year's focus was on the results of the DELIVER, EMPA-KIDNEY and SURMOUNT-1 trials and their implications for the treatment of heart failure (HF) and chronic kidney disease (CKD) with sodium-glucose cotransporter-2 (SGLT2) inhibitors and obesity with glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonists. A broad audience of primary care physicians, diabetologists, endocrinologists, cardiologists, and nephrologists participated online in discussions on new consensus recommendations and guideline updates on type 2 diabetes (T2D) and CKD management, overcoming clinical inertia, glycemic markers, continuous glucose monitoring (CGM), novel insulin preparations, combination therapy, and reclassification of T2D. The impact of cardiovascular outcomes on the design of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) trials, as well as the impact of real-world evidence (RWE) studies on the confirmation of CVOT outcomes and clinical trial design, were also intensively discussed. The 9th Cardiovascular Outcome Trial Summit will be held virtually on November 23-24, 2023 ( http://www.cvot.org ).

Gout Prevalence, Practice Patterns, and Associations with Outcomes in North American Dialysis Patients.

INTRODUCTION: Gout occurs frequently in patients with kidney disease and can lead to a significant burden on quality of life. Gout prevalence, and its association with outcomes in hemodialysis (HD) and peritoneal dialysis (PD) populations located in North America, is unknown. METHODS: We used data from North America cohorts of 70,297 HD patients (DOPPS, 2012-2020) and 5117 PD patients (PDOPPS, 2014-2020). We used three definitions of gout for this analysis: (1) having an active prescription for colchicine or febuxostat; (2) having an active prescription for colchicine, febuxostat, or allopurinol; or (3) having an active prescription for colchicine, febuxostat, or allopurinol, or prior diagnosis of gout. Propensity score matching was used to compare outcomes among patients with versus without gout. Outcomes included erythropoietin resistance index (ERI=erythropoiesis stimulating agent dose per week/(hemoglobin×weight)), all-cause mortality, hospitalization, and patient-reported outcomes (PROs). RESULTS: The gout prevalence was 13% in HD and 21% in PD; it was highest among incident dialysis patients. Description of previous history of gout was rare, and identification of gout defined by colchicine (2%-3%) or febuxostat (1%) prescription was less frequent than by allopurinol (9%-12%). Both HD and PD patients with gout (versus no gout) were older, were more likely male, had higher body mass index, and had higher prevalence of cardiovascular comorbidities. About half of patients with a gout history were prescribed urate-lowering therapy. After propensity score matching, mean ERI was 3%-6% higher for gout versus non-gout patients while there was minimal evidence of association with clinical outcomes or PROs. CONCLUSION: In a large cohort of PD and HD patients in North America, we found that gout occurs frequently and is likely under-reported. Gout was not associated with adverse clinical or PROs.

Kidney outcomes with finerenone: an analysis from the FIGARO-DKD study.

BACKGROUND: In FIGARO-DKD, finerenone reduced the risk of cardiovascular events in patients with type 2 diabetes (T2D) and stage 1-4 chronic kidney disease (CKD). In FIDELIO-DKD, finerenone improved kidney and cardiovascular outcomes in patients with advanced CKD. This analysis further explores kidney outcomes in FIGARO-DKD. METHODS: FIGARO-DKD (NCT02545049) included patients with urine albumin-to-creatinine ratio (UACR) 30-<300 mg/g and estimated glomerular filtration rate (eGFR) 25-90 mL/min/1.73 m2 or UACR 300-5000 mg/g and eGFR ≥60 mL/min/1.73 m2. Outcomes included two composite kidney endpoints, a composite of ≥40% decrease in eGFR from baseline sustained over ≥4 weeks, kidney failure or renal death, and a composite of ≥57% decrease in eGFR from baseline sustained over ≥4 weeks, kidney failure or renal death. Changes in albuminuria and eGFR slope were also analyzed. Kidney and CV outcomes were evaluated by baseline UACR. RESULTS: A lower incidence rate for the eGFR ≥40% kidney composite endpoint was observed with finerenone compared with placebo, but the between-group difference was not significant [hazard ratio (HR) = 0.87; 95% confidence interval (CI): 0.76-1.01; P = .069]. A greater treatment effect was observed on the eGFR ≥57% kidney composite endpoint (HR = 0.77; 95% CI: 0.60-0.99; P = 0.041) with a 36% relative risk reduction for end-stage kidney disease. A larger magnitude of effect on kidney outcomes was observed with finerenone versus placebo for patients with severely increased albuminuria than with moderately increased albuminuria. Improvements in UACR, eGFR slope and cardiovascular risk were evident in both subgroups with finerenone. CONCLUSIONS: The present analyses suggest that finerenone protects against kidney disease progression and cardiovascular events in patients with T2D and early- or late-stage CKD.

Effect of hypoxia and uremia on oxidative stress on erythrocytes from hemodialysis patients.

Oxidative stress (OS) is essential in uremia-associated comorbidities, including renal anemia. Complications experienced by hemodialysis (HD) patients, such as hypoxemia and uremic toxins accumulation, induce OS and premature death of red blood cells (RBC). We aimed to characterize reactive oxygen species (ROS) production and antioxidant pathways in HD-RBC and RBC from healthy controls (CON-RBC) and evaluate the role of uremia and hypoxia in these pathways. ROS production, xanthine oxidase (XO) and superoxide dismutase (SOD) activities, glutathione (GSH), and heme oxygenase-1 (HO-1) levels were measured using flow cytometry or spectrophotometry in CON-RBC and HD-RBC (pre- and post-HD), at baseline and after 24 h incubation with uremic serum (S-HD) and/or under hypoxic conditions (5% O2 ). Ketoprofen was used to inhibit RBC uremic toxins uptake. HD-RBC showed higher ROS levels and lower XO activity than CON-RBC, particularly post-HD. GSH levels were lower, while SOD activity and HO-1 levels of HD-RBC were higher than control. Hypoxia per se triggered ROS production in CON-RBC and HD-RBC. S-HD, on top of hypoxia, increased ROS levels. Inhibition of uremic toxins uptake attenuated ROS of CON and HD-RBC under hypoxia and uremia. CON-RBC in uremia and hypoxia showed lower GSH levels than cells in normoxia and non-uremic conditions. Redox mechanisms of HD-RBC are altered and prone to oxidation. Uremic toxins and hypoxia play a role in unbalancing these systems. Hypoxia and uremia participate in the pathogenesis of OS in HD-RBC and might induce RBC death and thus compound anemia.

Kidney Function in Factory Workers Exposed to Heat Stress: A 2-Year Follow-up Study.

OBJECTIVES: The aims of the study are to re-evaluate kidney function in workers exposed and not exposed to heat stress after 2 years and to compare kidney function cross-shift using creatinine and cystatin C. METHODS: Participants were workers from a metallurgical industry. The clinical and biochemical markers of hydration and kidney function were evaluated before and after a single shift in work. RESULTS: We included 14 workers (6 in the heat group and 8 in the control group). The serum creatinine levels did not change during the follow-up period. Cross-shift, creatinine-based eGFR (estimated glomerular filtration rate) decreased, and cystatin C-based eGFR was maintained in the heat and control groups. CONCLUSIONS: Workers exposed to heat stress maintained their kidney function after a 2-year follow-up. Cystatin C is a better kidney function marker than creatinine for cross-shift assessments in this setting.

Kidney function and daily emtricitabine/tenofovir disoproxil fumarate pre-exposure prophylaxis against HIV: results from the real-life multicentric demonstrative project PrEP Brazil.

BACKGROUND: Pre-Exposure Prophylaxis (PrEP) has demonstrated efficacy in the reduction of sexually transmitted HIV infections. The prolonged use of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) co-formulation (TDF/FTC), however, may result in augmented risk of renal toxicity. We aimed to evaluate changes in the estimated Glomerular Filtration Rate (eGFR) in a real-world population setting of participants enrolled in PrEP Brazil, a 48-week prospective, open-label, demonstration study to assess the feasibility of daily oral TDF/FTC used by men who have sex with men and transgender women at high-risk of HIV infection, all over 18 years old. METHODS: Kidney function was assessed by serial measurement of serum creatinine and eGFR with the Modification of Diet in Renal Disease Study (MDRD) formula on weeks 4, 12, 24, 36 and 48. Adherence to PrEP was assessed by dosing TDF concentration in dried blood spots at weeks 4 and 48, measured by liquid chromatography-mass spectrometry or mass spectrometry. RESULTS: Of 392 participants completing the 48-week follow-up protocol with TDF blood detectable levels and eGFR measures, 43.1% were young adults, of Caucasian ethnic background (57.9%), with BMI below 30 kg/m2, without arterial hypertension. At screening, median eGFR was 93.0 mL/min/1.73 m2. At week 4 follow-up, 90 (23% of the study population) participants presented reductions in eGFR greater than 10 mL/min/1.73 m2 as compared to baseline eGFR, some as large as 59 mL/min/1.73 m2, but with no clinical outcomes (adverse events and renal adverse events) severe enough to demand TDF/FTC discontinuation. A negative relationship was observed between TDF blood levels and eGFR at weeks 4 (r = - 0.005; p < 0.01) and 48 (r = - 0.006; p < 0.01). CONCLUSIONS: These results suggest that the renal function profile in individuals on TDF/FTC may be assessed on week 4 and then only annually, allowing a more flexible medical follow-up in primary care centers.

Risk factors for incident kidney disease in older adults: an Australian prospective population-based study.

BACKGROUND AND AIM: To determine risk factors for incident chronic kidney disease (CKD) in a large population-based cohort. METHODS: This prospective opt-in population-based cohort study is based on the 45 and Up Study, where New South Wales residents aged ≥45 years were randomly sampled from the Services Australia database and agreed to complete the 45 and Up Study baseline questionnaire and have their responses linked to their health data in routinely collected databases. The primary outcome was the development of incident CKD, defined as eGFR < 60 mL/min/1.73 m2 . CKD incidence was calculated using Poisson regression. Risk factors for incident CKD were assessed using Cox regression in multivariable models. RESULTS: In 39 574 participants who did not have CKD at enrolment, independent factors associated with developing CKD included: older age, regional residence (HR 1.38 (1.27-1.50) for outer regional vs major city), smoking (1.13 (1.00-1.27) for current smoker vs non-smoker), obesity (1.25 (1.16-1.35) for obese vs normal body mass index), diabetes mellitus (1.41 (1.33-1.50)), hypertension (1.53 (1.44-1.62)), coronary heart disease (1.13 (1.07-1.20)), depression/anxiety (1.16 (1.09-1.24)) and cancer (1.29 (1.20-1.39)). Migrants were less likely to develop CKD compared with people born in Australia (0.88 (0.83-0.94)). Gender, partner status and socioeconomic factors were not independently associated with developing CKD. CONCLUSIONS: This large population-based study found multiple modifiable and non-modifiable factors were independently associated with developing CKD. In the Australian setting, the risk of CKD was higher with regional residence. Differences according to socioeconomic status were predominantly explained by age, comorbidities and harmful health-related behaviours.

Assessing the impact of screening, early identification and intervention programmes for chronic kidney disease: protocol for a scoping review.

INTRODUCTION: Chronic kidney disease (CKD) is a major threat to public health, especially in low-income and lower middle-income countries, where resources for treating patients with advanced CKD are scarce. Although early CKD identification and intervention hold promise for reducing the burden of CKD and risk factors, it remains unclear if an uniform strategy can be applicable across all income groups. The aim of this scoping review is to synthesise available evidence on early CKD identification programmes in all world regions and income groups. The study will also identify efforts that have been made to use interventions and implementation of early identification programmes for CKD across countries and income groups. METHODS AND ANALYSIS: This review will be guided by the methodological framework for conducting scoping studies developed by Arksey and O'Malley. Empirical (Medline, Embase, Cochrane Library, CINAHL, ISI Web of Science and PsycINFO) and grey literature references will be searched to identify studies on CKD screening, early identification and interventions across all populations. Two reviewers will independently screen references in consecutive stages of title/abstract screening and then full-text screening. We will use a general descriptive overview, tabular summaries and content analysis on extracted data. ETHICS AND DISSEMINATION: The findings from our planned scoping review will enable us to identify items in early identification programmes that can be used in developing screening toolkits for CKD. We will disseminate our findings using traditional approaches that include open-access peer-reviewed publication, scientific presentations and a white paper (call to action) report. Ethical approval will not be required for this scoping review as the data will be extracted from already published studies.

Serum Biomarkers of Iron Stores Are Associated with Increased Risk of All-Cause Mortality and Cardiovascular Events in Nondialysis CKD Patients, with or without Anemia.

BACKGROUND: Approximately 30%-45% of patients with nondialysis CKD have iron deficiency. Iron therapy in CKD has focused primarily on supporting erythropoiesis. In patients with or without anemia, there has not been a comprehensive approach to estimating the association between serum biomarkers of iron stores, and mortality and cardiovascular event risks. METHODS: The study included 5145 patients from Brazil, France, the United States, and Germany enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study, with first available transferrin saturation (TSAT) and ferritin levels as exposure variables. We used Cox models to estimate hazard ratios (HRs) for all-cause mortality and major adverse cardiovascular events (MACE), with progressive adjustment for potentially confounding variables. We also used linear spline models to further evaluate functional forms of the exposure-outcome associations. RESULTS: Compared with patients with a TSAT of 26%-35%, those with a TSAT ≤15% had the highest adjusted risks for all-cause mortality and MACE. Spline analysis found the lowest risk at TSAT 40% for all-cause mortality and MACE. Risk of all-cause mortality, but not MACE, was also elevated at TSAT ≥46%. Effect estimates were similar after adjustment for hemoglobin. For ferritin, no directional associations were apparent, except for elevated all-cause mortality at ferritin ≥300 ng/ml. CONCLUSIONS: Iron deficiency, as captured by TSAT, is associated with higher risk of all-cause mortality and MACE in patients with nondialysis CKD, with or without anemia. Interventional studies evaluating the effect on clinical outcomes of iron supplementation and therapies for alternative targets are needed to better inform strategies for administering exogenous iron.

Is a treat-to-target approach to lipid-lowering therapy appropriate in patients with chronic kidney disease? A prospective French cohort study.

BACKGROUND: Whereas European guidelines recommend adjusting lipid-lowering therapy (LLT) to meet prespecified targets ('treat-to-target') for low-density lipoprotein cholesterol (LDL-C), other guidelines do not ('fire and forget'). In a large observational prospective cohort, we sought to evaluate which strategy could be associated with better cardiovascular outcomes in chronic kidney disease (CKD). METHODS: In CKD-REIN, patients (CKD stages 3 and 4) on LLT were categorized according to achievement of LDL-C targets for high and very high cardiovascular risk (< 2.6 and < 1.8 mmol/L, respectively) at baseline. Primary outcome was fatal/non-fatal atheromatous cardiovascular disease (CVD). Secondary outcomes were non-atheromatous CVD, atheromatous or non-atheromatous CVD, and major adverse cardiovascular events. RESULTS: The population comprised 1521 patients (68 ± 12 years, 31% women, mean estimated glomerular filtration rate [eGFR] 35 mL/min/1.73 m2). Overall, 523 (34%) met their LDL-C targets at baseline. Median follow-up was 2.9 years (interquartile range 2.2-3.0). Incidence rates per 100 patient-years were 6.2% (95% confidence interval [CI] 5.5-7.0) for atheromatous CVD, 9.2% (8.3-10.1) for non-atheromatous CVD, 15.2% (14.0-16.4) for atheromatous/non-atheromatous CVD, and 6.3% (5.5-7.1) for major adverse cardiovascular events. Corresponding rates in patients who achieved targets were 6.6%, 9.8%, 16.1%, and 6.3%, respectively. Target achievement was not associated with risk of fatal/non-fatal atheromatous CVD (adjusted hazard ratio 1.04, 95% CI 0.76-1.44, p = 0.77) or fatal/non-fatal atheromatous or non-atheromatous CVD (0.98, 0.78-1.23, p = 0.91). CONCLUSIONS: These findings do not appear to support a treat-to-target approach in CKD patients on LLT, and may favor the hypothesis of an advantage of fire-and-forget. Randomized trials are needed to confirm this theory.

High prevalence of biochemical disturbances of chronic kidney disease - mineral and bone disorders (CKD-MBD) in a nation-wide peritoneal dialysis cohort: are guideline goals too hard to achieve? / Alta Prevalência de Distúrbios Bioquímicos Minerais e Ósseos na Doença Renal Crônica em uma coorte de diálise peritoneal nacional: as metas das diretrizes são muito difíceis de alcançar?

Abstract Introduction: Chronic kidney disease - mineral and bone disorders (CKD-MBD) are common in dialysis patients. Definition of targets for calcium (Ca), phosphorus (P), parathormone (iPTH), and alkaline phosphatase (ALP) and their treatment recommendations, are provided by international guidelines. There are few studies analyzing CKD-MBD in peritoneal dialysis (PD) patients and the impact of guidelines on mineral metabolism control. The aim of our study was to describe the prevalence of biomarkers for CKD-MBD in a large cohort of PD patients in Brazil. Methods: Data from the nation-wide prospective observational cohort BRAZPD II was used. Incident patients were followed between December 2004 and January 2011. According to KDOQI recommendations, reference ranges for total Ca were 8.4 to 9.5 mg/dL, for P, 3.5 to 5.5 mg/dL, for iPTH, 150-300 pg/mL, and for ALP, 120 U/L. Results: Mean age was 59.8 ± 16 years, 48% were male, and 43% had diabetes. In the beginning, Ca was 8.9 ± 0.9 mg/dL, and 48.3% were on the KODQI target. After 1 year, Ca increased to 9.1 ± 0.9 mg/dL and 50.4% were in the KDOQI preferred range. P at baseline was 5.2 ± 1.6 mg/dL, with 52.8% on target, declining to 4.9 ± 1.5 mg/dL after one year, when 54.7% were on target. Median iPTH at baseline was 238 (P25% 110 - P75% 426 pg/mL) and it remained stable throughout the first year; patients within target ranged from 26 to 28.5%. At the end of the study, 80% was in 3.5 meq/L Ca dialysate concentration, 66.9% of patients was taking any phosphate binder, and 25% was taking activated vitamin D. Conclusions: We observed a significant prevalence of biochemical disorders related to CKD-MBD in this dialysis population.

Resumo Introdução: Os distúrbios minerais e ósseos da doença renal crônica (DMO-DRC) são comuns em pacientes em diálise. A definição de metas para cálcio (Ca), fósforo (P), paratormônio (PTHi) e fosfatase alcalina (FA) e suas recomendações de tratamento são fornecidas por diretrizes internacionais. Há poucos estudos analisando o DMO-DRC em pacientes em diálise peritoneal (DP) e o impacto das diretrizes no controle do metabolismo mineral. O objetivo do nosso estudo foi descrever a prevalência de alterações nos marcadores para DMO-DRC em uma grande coorte de pacientes em DP no Brasil. Métodos: Foram utilizados dados da coorte observacional prospectiva nacional BRAZPD II. Pacientes incidentes foram acompanhados entre Dezembro de 2004 e Janeiro de 2011. De acordo com as recomendações do KDOQI, os intervalos de referência para Ca total foram de 8,4 a 9,5 mg/dL, para P, 3,5 a 5,5 mg/dL, para PTHi, 150-300 pg/mL, e para FA, 120 U/L. Resultados: A idade média foi de 59,8 ± 16 anos, 48% eram homens e 43% tinham diabetes. No início, o Ca era de 8,9 ± 0,9 mg/dL, e 48,3% estavam na meta do KODQI. Após 1 ano, o Ca aumentou para 9,1 ± 0,9 mg/dL e 50,4% estavam na faixa preferida do KDOQI. P basal era 5,2 ± 1,6 mg/dL, com 52,8% na meta, diminuindo para 4,9 ± 1,5 mg/dL após um ano, quando 54,7% estavam na meta. O PTHi basal mediano foi de 238 (P25% 110 - P75% 426 pg/mL) e permaneceu estável durante o primeiro ano; os pacientes dentro da meta variaram de 26 a 28,5%. No final do estudo, 80% estavam na concentração de 3,5 meq/L de Ca dialisato, 66,9% dos pacientes estavam tomando qualquer quelante de fosfato, e 25% estavam tomando vitamina D ativada. Conclusões: Observamos uma prevalência significativa de distúrbios bioquímicos relacionados ao DMO-DRC nesta população em diálise.

Urgent-start dialysis in patients referred early to a nephrologist-the CKD-REIN prospective cohort study.

BACKGROUND: The lack of a well-designed prospective study of the determinants of urgent dialysis start led us to investigate its individual- and provider-related factors in patients seeing nephrologists. METHODS: The Chronic Kidney Disease Renal Epidemiology and Information Network (CKD-REIN) is a prospective cohort study that included 3033 patients with CKD [mean age 67 years, 65% men, mean estimated glomerular filtration rate (eGFR) 32 mL/min/1.73 m2] from 40 nationally representative nephrology clinics from 2013 to 2016 who were followed annually through 2020. Urgent-start dialysis was defined as that 'initiated imminently or <48 hours after presentation to correct life-threatening manifestations' according to the Kidney Disease: Improving Global Outcomes 2018 definition. RESULTS: Over a 4-year (interquartile range 3.0-4.8) median follow-up, 541 patients initiated dialysis with a known start status and 86 (16%) were identified with urgent starts. The 5-year risks for the competing events of urgent and non-urgent dialysis start, pre-emptive transplantation and death were 4, 17, 3 and 15%, respectively. Fluid overload, electrolytic disorders, acute kidney injury and post-surgery kidney function worsening were the reasons most frequently reported for urgent-start dialysis. Adjusted odds ratios for urgent start were significantly higher in patients living alone {2.14 [95% confidence interval (CI) 1.08-4.25] or with low health literacy [2.22 (95% CI 1.28-3.84)], heart failure [2.60 (95% CI 1.47-4.57)] or hyperpolypharmacy [taking >10 drugs; 2.14 (95% CI 1.17-3.90)], but not with age or lower eGFR at initiation. They were lower in patients with planned dialysis modality [0.46 (95% CI 0.19-1.10)] and more nephrologist visits in the 12 months before dialysis [0.81 (95% CI 0.70-0.94)] for each visit. CONCLUSIONS: This study highlights several patient- and provider-level factors that are important to address to reduce the burden of urgent-start dialysis.

Beta-2 microglobulin and all-cause mortality in the era of high-flux hemodialysis: results from the Dialysis Outcomes and Practice Patterns Study.

BACKGROUND: Beta-2 microglobulin (ß2M) accumulates in hemodialysis (HD) patients, but its consequences are controversial, particularly in the current era of high-flux dialyzers. High-flux HD treatment improves ß2M removal, yet ß2M and other middle molecules may still contribute to adverse events. We investigated patient factors associated with serum ß2M, evaluated trends in ß2M levels and in hospitalizations due to dialysis-related amyloidosis (DRA), and estimated the effect of ß2M on mortality. METHODS: We studied European and Japanese participants in the Dialysis Outcomes and Practice Patterns Study. Analysis of DRA-related hospitalizations spanned 1998-2018 (n = 23 976), and analysis of ß2M and mortality in centers routinely measuring ß2M spanned 2011-18 (n = 5332). We evaluated time trends with linear and Poisson regression and mortality with Cox regression. RESULTS: Median ß2M changed nonsignificantly from 2.71 to 2.65 mg/dL during 2011-18 (P = 0.87). Highest ß2M tertile patients (>2.9 mg/dL) had longer dialysis vintage, higher C-reactive protein and lower urine volume than lowest tertile patients (≤2.3 mg/dL). DRA-related hospitalization rates [95% confidence interval (CI)] decreased from 1998 to 2018 from 3.10 (2.55-3.76) to 0.23 (0.13-0.42) per 100 patient-years. Compared with the lowest ß2M tertile, adjusted mortality hazard ratios (95% CI) were 1.16 (0.94-1.43) and 1.38 (1.13-1.69) for the middle and highest tertiles. Mortality risk increased monotonically with ß2M modeled continuously, with no indication of a threshold. CONCLUSIONS: DRA-related hospitalizations decreased over 10-fold from 1998 to 2018. Serum ß2M remains positively associated with mortality, even in the current high-flux HD era.

A pre-specified analysis of the DAPA-CKD trial demonstrates the effects of dapagliflozin on major adverse kidney events in patients with IgA nephropathy.

Immunoglobulin A (IgA) nephropathy is a common form of glomerulonephritis, which despite use of renin-angiotensin-aldosterone-system blockers and immunosuppressants, often progresses to kidney failure. In the Dapagliflozin and Prevention of Adverse Outcomes in Chronic Kidney Disease trial, dapagliflozin reduced the risk of kidney failure and prolonged survival in participants with chronic kidney disease with and without type 2 diabetes, including those with IgA nephropathy. Participants with estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m2 and urinary albumin-to-creatinine ratio 200-5000 mg/g (22.6-565 mg/mol) were randomized to dapagliflozin 10mg or placebo, as adjunct to standard care. The primary composite endpoint was a sustained decline in eGFR of 50% or more, end-stage kidney disease, or death from a kidney disease-related or cardiovascular cause. Of 270 participants with IgA nephropathy (254 [94%] confirmed by previous biopsy), 137 were randomized to dapagliflozin and 133 to placebo, and followed for median 2.1 years. Overall, mean age was 51.2 years; mean eGFR, 43.8 mL/min/1.73m2; and median urinary albumin-to-creatinine ratio, 900 mg/g. The primary outcome occurred in six (4%) participants on dapagliflozin and 20 (15%) on placebo (hazard ratio, 0.29; 95% confidence interval, 0.12, 0.73). Mean rates of eGFR decline with dapagliflozin and placebo were -3.5 and -4.7 mL/min/1.73m2/year, respectively. Dapagliflozin reduced the urinary albumin-to-creatinine ratio by 26% relative to placebo. Adverse events leading to study drug discontinuation were similar with dapagliflozin and placebo. There were fewer serious adverse events with dapagliflozin, and no new safety findings in this population. Thus, in participants with IgA nephropathy, dapagliflozin reduced the risk of chronic kidney disease progression with a favorable safety profile.

Serum biomarkers of iron stores are associated with worse physical health-related quality of life in nondialysis-dependent chronic kidney disease patients with or without anemia.

BACKGROUND: Iron deficiency (ID) is a common condition in nondialysis-dependent chronic kidney disease (NDD-CKD) patients that is associated with poorer clinical outcomes. However, the effect of ID on health-related quality of life (HRQoL) in this population is unknown. We analyzed data from a multinational cohort of NDD-CKD Stages 3-5 patients to test the association between transferrin saturation (TSAT) index and ferritin with HRQoL. METHODS: Patients from Brazil (n = 205), France (n = 2015) and the USA (n = 293) in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps, 2013-2019) were included. We evaluated the association of TSAT and ferritin (and functional and absolute ID, defined as TSAT ≤20% and ferritin ≥300 or <50 ng/mL) on pre-specified HRQoL measures, including the 36-item Kidney Disease Quality of Life physical component summary (PCS) and mental component summary (MCS) as the primary outcomes. Models were adjusted for confounders including hemoglobin (Hb). RESULTS: TSAT ≤15% and ferritin <50 ng/mL and ≥300 ng/mL were associated with worse PCS scores, but not with MCS. Patients with composite TSAT ≤20% and ferritin <50 or ≥300 ng/mL had lower functional status and worse PCS scores than those with a TSAT of 20-30% and ferritin 50-299 ng/mL. Patients with a lower TSAT were less likely to perform intense physical activity. Adjustment for Hb only slightly attenuated the observed effects. CONCLUSIONS: Low TSAT levels, as well as both low TSAT with low ferritin and low TSAT with high ferritin, are associated with worse physical HRQoL in NDD-CKD patients, even after accounting for Hb level. Interventional studies of iron therapy on HRQoL among NDD-CKD individuals are needed to confirm these findings.

Executive summary of the KDIGO 2021 Clinical Practice Guideline for the Management of Blood Pressure in Chronic Kidney Disease.

The Kidney Disease: Improving Global Outcomes (KDIGO) 2021 Clinical Practice Guideline for the Management of Blood Pressure in Chronic Kidney Disease for patients not receiving dialysis represents an update to the KDIGO 2012 guideline on this topic. Development of this guideline update followed a rigorous process of evidence review and appraisal. Guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence. The strength of recommendations is based on the "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) approach. The scope includes topics covered in the original guideline, such as optimal blood pressure targets, lifestyle interventions, antihypertensive medications, and specific management in kidney transplant recipients and children. Some aspects of general and cardiovascular health, such as lipid and smoking management, are excluded. This guideline also introduces a chapter dedicated to proper blood pressure measurement since all large randomized trials targeting blood pressure with pivotal outcomes used standardized preparation and measurement protocols adhered to by patients and clinicians. Based on previous and new evidence, in particular the Systolic Blood Pressure Intervention Trial (SPRINT) results, we propose a systolic blood pressure target of less than 120 mm Hg using standardized office reading for most people with chronic kidney disease (CKD) not receiving dialysis, the exception being children and kidney transplant recipients. The goal of this guideline is to provide clinicians and patients a useful resource with actionable recommendations supplemented with practice points. The burden of the recommendations on patients and resources, public policy implications, and limitations of the evidence are taken into consideration. Lastly, knowledge gaps and recommendations for future research are provided.