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BackgroundChronic kidney disease (CKD) is characterized by dysbiosis, elevated levels of uremic toxins, systemic inflammation, and increased markers of oxidative stress. These factors lead to an increased risk of cardiovascular disease (CVD) which is common among CKD patients. Supplementation with high amylose maize resistant starch type 2 (RS-2) can change the composition of the gut microbiota, and reduce markers of inflammation and oxidative stress in patients with end-stage renal disease. However, the impact of RS-2 supplementation has not been extensively studied in CKD patients not on dialysis. Aerobic exercise training lowers certain markers of inflammation in CKD patients. Whether combining aerobic training along with RS-2 supplementation has an additive effect on the aforementioned biomarkers in predialysis CKD patients has not been previously investigated.MethodsThe study is being conducted as a 16-week, double-blind, placebo controlled, parallel arm, randomized controlled trial. Sixty stage 3-4 CKD patients (ages of 30-75 years) are being randomized to one of four groups: RS-2 & usual care, RS-2 & aerobic exercise, placebo (cornstarch) & usual care and placebo & exercise. Patients attend four testing sessions: Two baseline (BL) sessions with follow up visits 8 (wk8) and 16 weeks (wk16) later. Fasting blood samples, resting brachial and central blood pressures, and arterial stiffness are collected at BL, wk8 and wk16. A stool sample is collected for analysis of microbial composition and peak oxygen uptake is assessed at BL and wk16. Blood samples will be assayed for p-cresyl sulphate and indoxyl sulphate, c-reactive protein, tumor necrosis factor α, interleukin 6, interleukin 10, monocyte chemoattractant protein 1, malondialdehyde, 8-isoprostanes F2a, endothelin-1 and nitrate/nitrite. Following BL, subjects are randomized to their group. Individuals randomized to conditions involving exercise will attend three supervised moderate intensity (55-65% peak oxygen uptake) aerobic training sessions (treadmills, bikes or elliptical machine) per week for 16 weeks.DiscussionThis study has the potential to yield information about the effect of RS-2 supplementation on key biomarkers believed to impact upon the development of CVD in patients with CKD. We are examining whether there is an additive effect of exercise training and RS-2 supplementation on these key variables.Trial registrationClinicaltrials.gov Trial registration# NCT03689569 . 9/28/2018, retrospectively registered.

Background: Chronic kidney disease (CKD) is a progressive and usually irreversible disease. Different types of outcomes are of interest in the course of CKD such as time-to-dialysis, transplantation or decline of the glomerular filtration rate (GFR). Statistical analyses aiming at investigating the association between these outcomes and risk factors raise a number of methodological issues. The objective of this study was to give an overview of these issues and to highlight some statistical methods that can address these topics. Methods: A literature review of statistical methods published between 2002 and 2012 to investigate risk factors of CKD outcomes was conducted within the Scopus database. The results of the review were used to identify important methodological issues as well as to discuss solutions for each type of CKD outcome. Results: Three hundred and four papers were selected. Time-to-event outcomes were more often investigated than quantitative outcome variables measuring kidney function over time. The most frequently investigated events in survival analyses were all-cause death, initiation of kidney replacement therapy, and progression to a specific value of GFR. While competing risks were commonly accounted for, interval censoring was rarely acknowledged when appropriate despite existing methods. When the outcome of interest was the quantitative decline of kidney function over time, standard linear models focussing on the slope of GFR over time were almost as often used as linear mixed models which allow various numbers of repeated measurements of kidney function per patient. Informative dropout was accounted for in some of these longitudinal analyses. Conclusions: This study provides a broad overview of the statistical methods used in the last ten years for investigating risk factors of CKD progression, as well as a discussion of their limitations. Some existing potential alternatives that have been proposed in the context of CKD or in other contexts are also highlighted. [ABSTRACT FROM AUTHOR]

Background: The vasoconstricting peptide endothelin-1 (ET-1) is associated with endothelial dysfunction. The aim of this paper was to investigate whether circulating ET-1 levels predicts chronic kidney disease (CKD) in a prospective population study.Methods: In 2002-2005, 2816 participants (30-74 years) were randomly selected from two municipalities in South-Western Sweden and followed up in a representative sample of 1327 individuals after 10 years. Endothelin-1 levels were assessed at baseline. Outcome was defined as CKD stage 3 or above based on eGFR < 60 mL/min/1.73m2. Those 1314 participants with successful analysis of ET-1 were further analyzed using binary logistic regression.Results: At follow-up, 51 (8%) men and 47 (7,8%) women had CKD stage 3 and above. Based on levels of ET-1 the population was divided into quintiles showing that women in the highest quintile (n = 132) had a significantly increased risk of developing CKD during the follow up period (OR = 2.54, 95% CI:1.19-5.45, p = 0.02) compared with the other quintiles (1-4). The association was borderline significant after adjusted for age, current smoking, alcohol consumption, hypertension, diabetes, BMI, high- sensitive CRP and LDL-cholesterol (OR = 2.25, 95% CI:0.97-5.24, p = 0.06). No significant differences were observed between quintiles of ET-1 and development of CKD in men (NS).Conclusions: High levels of ET-1 are associated with development of CKD in women. [ABSTRACT FROM AUTHOR]

Background: Understanding the patient perspective of frailty is critical to offering holistic patient-centred care. Rehabilitation strategies for patients with advanced chronic kidney disease (CKD) and frailty are limited in their ability to overcome patient-perceived barriers to participation, resulting in high rates of drop-out and non-adherence. The aim of this study was to explore patient perspectives and preferences regarding experiences with rehabilitation to inform a CKD/Frailty rehabilitation model. Methods: This qualitative study involved two focus groups, six individual semi-structured interviews and three caregiver semi-structured interviews with lived experience of advanced kidney disease and frailty. Interviews were recorded, transcribed, and coded for meaningful concepts and analysed using inductive thematic analysis using constant comparative method of data analysis employing Social Cognitive Theory. Results: Six major themes emerged including accommodating frailty is an act of resilience, exercise is endorsed for rehabilitation but existing programs have failed to meet end-users' needs. Rehabilitation goals were framed around return to normative behaviours and rehabilitation should have a social dimension, offering understanding for "people like us". Participants reported on barriers and disruptors to frailty rehabilitation in the CKD context. Participants valued peer-to-peer education, the camaraderie of socialisation and the benefit of feedback for maintaining motivation. Patients undertaking dialysis described the commodity of time and the burden of unresolved symptoms as barriers to participation. Participants reported difficulty envisioning strategies for frailty rehabilitation, maintaining a focus on the immediate and avoidance of future uncertainty. Conclusions: Frailty rehabilitation efforts in CKD should leverage shared experiences, address comorbidity and symptom burden and focus on goals with normative value. [ABSTRACT FROM AUTHOR]

Background: Frailty increases risk of morbidity and mortality in hemodialysis patients. Frailty assessments could trigger risk reduction interventions if broadly adopted in clinical practice. We aimed to assess the clinical feasibility of frailty assessment among Veteran hemodialysis patients. Methods: Hemodialysis patients' ≥50 years were recruited from a single dialysis unit between 9/1/2021 and 3/31/2022.Patients who consented underwent a frailty phenotype assessment by clinical staff. Five criteria were assessed: unintentional weight loss, low grip strength, self-reported exhaustion, slow gait speed, and low physical activity. Participants were classified as frail (3–5 points), pre-frail (1–2 points) or non-frail (0 points). Feasibility was determined by the number of eligible participants completing the assessment. Results: Among 82 unique dialysis patients, 45 (52%) completed the assessment, 13 (16%) refused, 18 (23%) were not offered the assessment due to death, transfers, or switch to transplant or peritoneal dialysis, and 6 patients were excluded because they did not meet mobility criteria. Among assessed patients, 40(88%) patients were identified as pre-frail (46.6%) or frail (42.2%). Low grip strength was most common (90%). Those who refused were more likely to have peripheral vascular disease (p = 0.001), low albumin (p = 0.0187), low sodium (p = 0.0422), and ineligible for kidney transplant (p = 0.005). Conclusions: Just over half of eligible hemodialysis patients completed the frailty assessment suggesting difficulty with broad clinical adoption expectations. Among those assessed, frailty and pre-frailty prevalence was high. Given patients who were not tested were clinically high risk, our reported prevalence likely underestimates true frailty prevalence. Providing frailty reduction interventions to all hemodialysis patients could have high impact for this group. [ABSTRACT FROM AUTHOR]

BackgroundPrior papers have been inconsistent regarding how much creatinine clearance (CrCl) overestimates glomerular filtration rate (GFR). A recent cross-sectional study suggested that measurement error alone could entirely account for the longstanding observation that CrCl/GFR ratio is larger when GFR is lower among patients with chronic kidney disease (CKD); but there have been no validation of this in other cohorts.MethodsTo fill these gaps in knowledge regarding the relation between CrCl and GFR, we conducted cross-sectional and longitudinal analysis of the Modification of Diet in Renal Disease study (MDRD) and African American Study of Kidney Disease and Hypertension (AASK); and cross-sectional analysis of a clinical dataset from the Mayo Clinic of four different patient populations (CKD patients, kidney transplant recipients, post kidney donation subgroup and potential kidney donors). In the cross-sectional analyses (MDRD, AASK and Mayo Clinic cohort), we examined the relation between the CrCl/iothalamate GFR (iGFR) ratio at different categories of iGFR or different levels of CrCl. In the MDRD and AASK longitudinal analyses, we studied how the CrCl/iGFR ratio changed with those who had improvement in iGFR (CrCl) over time versus those who had worsening of iGFR (CrCl) over time.ResultsObserved CrCl/iGFR ratios were generally on the lower end of the range reported in the literature for CKD (median 1.24 in MDRD, 1.13 in AASK and 1.25 in Mayo Clinic cohort). Among CKD patients in whom CrCl and iGFR were measured using different timed urine collections, CrCl/iGFR ratio were higher with lower iGFR categories but lower with lower CrCl categories. However, among CKD patients in whom CrCl and iGFR were measured using the same timed urine collections (which reduces dis-concordant measurement error), CrCl/iGFR ratio were higher with both lower iGFR categories and lower CrCl categories.ConclusionsThese data refute the recent suggestion that measurement error alone could entirely account for the longstanding observation that CrCl/GFR ratio increases as GFR decreases in CKD patients. They also highlight the lack of certainty in our knowledge with regard to how much CrCl actually overestimates GFR.

Background: An important aspect of end-of-life decisions in dialysis patients is elective withdrawal from dialysis therapy. Several studies have shown that clinical factors, such as comorbidity, play a role in dialysis withdrawal. The role of symptoms of anxiety and depression is largely unknown. The. Methods: A prospective multi-center study has been set up to investigate anxiety and depressive symptoms longitudinally in dialysis patients. Anxiety and depressive symptoms were investigated using the Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI) as baseline. Adverse events, including dialysis withdrawal and mortality were registered during follow-up. Multivariable cox proportional hazard models were used with anxiety and depression as the independent variable and dialysis withdrawal as the outcome variable. Models included age, sex, ethnicity and a set of clinical comorbidities. Results: A total of 687 patients were included between 2012 and 2017, with a median follow-up of 3.2 years. A total of 48 patients (7%) withdrew from dialysis therapy, and subsequently deceased. Anxiety and depressive symptoms at baseline showed an association with dialysis withdrawal with hazard ratios of 2.31 (1.09–4.88) for anxiety and 2.56 (1.27–5.15) for depressive symptoms, independent of somatic comorbidities. Discussion: Withdrawal from dialysis therapy is associated with anxiety and depressive symptoms. Dialysis patients with more severe depressive and anxiety symptoms were more vulnerable for dialysis withdrawal. Insight in factors that play a role in dialysis withdrawal could aid patients and clinicians making an informed decision and develop clinical guidelines. [ABSTRACT FROM AUTHOR]

A recent article in the journal reported analyses of KDQOL-36™ survey data collected from 240,343 adults (330,412 surveys) dialyzed at a large dialysis organization in the United States during 2014-2016. The authors concluded that the KDQOL-36™ Symptoms and Problems of Kidney Disease scale had the highest mean score of the KDQOL-36™ scales. We note that this inference was erroneous because the scales are not scored on the same numeric scale. In addition, the authors found that responses to a general health perceptions item ("In general, would you say your health is excellent, very good, good, fair, or poor") was not significantly associated with any of the 5 KDQOL-36 scale scores. In contrast, we find significant and noteworthy correlations in two other datasets. These analytic issues call into question the accuracy and validity of the conclusions of this paper.

Background: Cardiovascular (CV) disease is the leading cause of mortality in patients with end-stage kidney disease (ESKD). The aim of the present study was to determine whether Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9) could be an independent predictor of CV events and all-cause mortality in black African haemodialysis patients.Methods: We carried out a prospective cohort study of all consecutive hemodialysis (HD) patients between August 2016 and July 2020, admitted in six hemodialysis centers of Kinshasa, Democratic Republic of Congo. Independent determinants of plasma PCSK-9 measured by ELISA were sought using multiple linear regression analysis. Kaplan-Meier's method described the incidence of CV events while competitive and proportional risk models looked for independent risk factors for death at the .05 significance level.Results: Out of 207 HD patients, 91 (43.9%) died; 116 (56.1%) have survived. PCSK9 level was significantly higher in deceased patients compared to survivors: 28.0 (24.0-31.0) ng/l vs 9.6 (8.6-11.6) ng/ml (p <  0.001). Patients with plasma PCSK9 levels in tertile 3 had a higher incidence of CV events and mortality compared to patients with plasma PCSK9 levels in tertile 2 or tertile 1 (p <  0.001). Tertile 3 negatively influence survival rates (26.6%) compared to tertile 2 (54.7%) and tertile 1 (85.3%). Patients in tertile 3 and tertile 2 had a 4-fold higher risk of death than patients in tertile 1. After adjustment for all parameters, competitive risk analysis showed that mortality was 2 times higher in patients with stroke. Similarly, serum albumin < 3.5 g/dL or PCSK9 in tertile 3 were respectively associated with 2 or 6 times higher rates of deaths.Conclusion: Elevated plasma PCSK9 level is an independent major predictor of incident CV events and all-cause mortality in black African HD patients. [ABSTRACT FROM AUTHOR]

Background: End stage kidney disease (ESKD) is associated with many losses, subsequently impacting mental wellbeing. Few studies have investigated the efficacy of psychosocial interventions for people with ESKD and none exist for Indigenous people, a population in which the ESKD burden is especially high.Methods: This three-arm, waitlist, single-blind randomised controlled trial examined efficacy of the Stay Strong App in improving psychological distress (Kessler distress scale; K10), depressive symptoms (adapted Patient Health Questionnaire; PHQ-9), quality of life (EuroQoL; EQ. 5D) and dialysis adherence among Indigenous Australians undergoing haemodialysis in central and northern Australia (Alice Springs and Darwin), with follow up over two 3-month periods. Effects of immediate AIMhi Stay Strong App treatment were compared with those from a contact control app (The Hep B Story) and treatment as usual (TAU). Control conditions received the Stay Strong intervention after 3 months.Results: Primary analyses of the full sample (N = 156) showed statistically significant decreases in K10 and PHQ-9 scores at 3 months for the Hep B Story but not for the Stay Strong app or TAU. Restricting the sample to those with moderate to severe symptoms of distress or depression (K10 > =25 or PHQ-9 > =10) showed significant decreases in K10 and PHQ-9 scores for both Stay Strong and Hep B Story. No significant differences were observed for the EQ-5D or dialysis attendance.Conclusions: Findings suggest that talking to people about their wellbeing and providing information relevant to kidney health using culturally adapted, locally relevant apps improve the wellbeing of people on dialysis. Further research is required to replicate these findings and identify active intervention components.Trial Registration: ACTRN12617000249358 ; 17/02/2017. [ABSTRACT FROM AUTHOR]

Background: The renal vasculature plays important roles in both homeostasis and pathology. In this study, we examined pathological changes in the renal microvascular in mouse models of kidney diseases.Methods: Glomerular lesions (GLs) in autoimmune disease-prone male BXSB/MpJ-Yaa (Yaa) mice and tubulointerstitial lesions (TILs) in male C57BL/6 mice subjected to unilateral ureteral obstruction (UUO) for 7 days were studied. Collected kidneys were examined using histopathological techniques. A nonparametric Mann-Whitney U test (P < 0.05) was performed to compare healthy controls and the experimental mice. The Kruskal-Wallis test was used to compare three or more groups, and multiple comparisons were performed using Scheffe's method when significant differences were observed (P < 0.05).Results: Yaa mice developed severe autoimmune glomerulonephritis, and the number of CD34+ glomerular capillaries decreased significantly in GLs compared to that in control mice. However, UUO-treated mice showed severe TILs only, and CD34+ tubulointerstitial capillaries were decreased significantly in TILs with the progression of tubulointerstitial fibrosis compared to those in untreated control kidneys. Infiltrations of B-cells, T-cells, and macrophages increased significantly in the respective lesions of both disease models (P < 0.05). In observations of vascular corrosion casts by scanning electron microscopy and of microfil rubber-perfused thick kidney sections by fluorescence microscopy, segmental absences of capillaries were observed in the GLs and TILs of Yaa and UUO-treated mice, respectively. Further, transmission electron microscopy revealed capillary endothelial injury in the respective lesions of both models. The numbers of CD34+ glomerular and tubulointerstitial capillaries were negatively correlated with all examined parameters in GLs (P < 0.05) and TILs (P < 0.01), respectively.Conclusions: From the analysis of mouse models, we identified inverse pathological correlations between the number of local capillaries in GLs and TILs and the severity of kidney diseases. [ABSTRACT FROM AUTHOR]

Background: Advances in technology and the ability to interrogate disease pathogenesis using systems biology approaches are exploding. As exemplified by the substantial progress in the personalized diagnosis and treatment of cancer, the application of systems biology to enable precision medicine in other disciplines such as Nephrology is well underway. Infrastructure that permits the integration of clinical data, patient biospecimens and advanced technologies is required for institutions to contribute to, and benefit from research in molecular disease classification and to devise specific and patient-oriented treatments.Methods and Results: We describe the establishment of the Biobank for the Molecular Classification of Kidney Disease (BMCKD) at the University of Calgary, Alberta, Canada. The BMCKD consists of a fully equipped wet laboratory, an information technology infrastructure, and a formal operational, ethical and legal framework for banking human biospecimens and storing clinical data. The BMCKD first consolidated a large retrospective cohort of kidney biopsy specimens to create a population-based renal pathology database and tissue inventory of glomerular and other kidney diseases. The BMCKD will continue to prospectively bank all kidney biopsies performed in Southern Alberta. The BMCKD is equipped to perform molecular, clinical and epidemiologic studies in renal pathology. The BMCKD also developed formal biobanking procedures for human specimens such as blood, urine and nucleic acids collected for basic and clinical research studies or for advanced diagnostic technologies in clinical care. The BMCKD is guided by standard operating procedures, an ethics framework and legal agreements with stakeholders that include researchers, data custodians and patients. The design and structure of the BMCKD permits its inclusion in a wide variety of research and clinical activities.Conclusion: The BMCKD is a core multidisciplinary facility that will bridge basic and clinical research and integrate precision medicine into renal pathology and nephrology. [ABSTRACT FROM AUTHOR]

Background: Patients with chronic kidney disease (CKD) commonly have unmet information needs. Greater patient participation in healthcare discussions can address these needs and improve health outcomes. We developed a patient-centered question prompt sheet (QPS) to engage CKD patients in healthcare conversations. Methods: We conducted a two phase, mixed-methods, cross-sectional study involving semi-structured telephone interviews. Patients with an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m², on dialysis, or with a kidney transplant were recruited from one Veterans Affairs (VA) nephrology clinic. Phase 1 interviews included open-ended questions assessing patients' CKD-related information needs and generated a preliminary 67-item QPS. Phase 2 interview participants rated the importance of asking each question on a 5-point Likert scale and provided open-ended feedback. All participants rated their willingness to use a CKD-QPS. Input from patient ratings, a multidisciplinary team, and from members of the National Kidney Disease Education Program (NKDEP) Coordinating Panel helped to shorten and refine the QPS. A qualitative thematic approach was used to analyze open-ended responses. Quantitative data were analyzed for means and proportions. Results: Eighty-five patients participated. Most were male (97 %), non-Hispanic white (71 %), and mean age was 67 years. Patients desired more information about CKD, particularly dialysis/transplant, and the relationship between CKD and comorbid medical conditions. The final QPS included 31-questions divided into 7 CKD subtopics. Most patients (88 %) reported being 'completely' or 'very' willing to use a CKD-QPS in future doctor visits. Conclusions: CKD patients have unmet information needs. We developed a QPS to engage CKD patients in healthcare discussions and to facilitate patient-centered care. Future research should assess whether the CKD-QPS addresses patients' information needs, enhances doctor-patient communication, and improves health outcomes. [ABSTRACT FROM AUTHOR]

Background: Low protein diets (LPD) have long been prescribed to chronic kidney disease patients with the goals of improving metabolic abnormalities and postpone the start of maintenance dialysis.Methods: We reviewed the recent literature addressing low protein diets supplemented with ketoacids/essential aminoacids prescribed during chronic kidney disease and their effects on metabolic, nutritional and renal parameters since 2013.Results: We show new information on how to improve adherence to these diets, on metabolic improvement and delay of the dialysis needs, and preliminary data in chronic kidney disease associated pregnancy. In addition, data on incremental dialysis have been reviewed, as well as potential strategies to reverse protein energy wasting in patients undergoing maintenance dialysis.Conclusion: These recent data help to better identify the use of low protein diets supplemented with ketoacids/essential aminoacids during chronic kidney disease. [ABSTRACT FROM AUTHOR]

Background: The number of elderly people over the age of 65 commencing dialysis in NZ has increased by almost 400% in the past decade. Few data are available about health related outcomes and survival on dialysis in the elderly to help the individual, their family, clinicians and health planners with decision-making. Methods/design: This study will provide the first comprehensive longitudinal survey of health-related quality of life (HRQOL) and other patient centred outcomes for individuals aged ⩾65 years on, or eligible for, dialysis therapy and will link these data to survival outcomes. Data collected by yearly structured interviews with participants will be linked to co-morbidity data, health service use, and laboratory information collected from health records, and analysed with respect to HRQOL and survival. The information obtained will inform the delivery of dialysis services in New Zealand and facilitate improved decision-making by individuals, their family and clinicians, about the appropriateness and impact of dialysis therapy on subsequent health and survival. Discussion: Results from this study will make possible more informed decision-making by future elderly patients and their families as they contemplate renal replacement therapy. Results will also allow health professionals to more accurately describe the impact of dialysis therapy on quality of life and outcomes for patients. [ABSTRACT FROM AUTHOR]