Efficacy and safety of aldosterone synthase inhibition with and without empagliflozin for chronic kidney disease: a randomised, controlled, phase 2 trial.

BACKGROUND: Excess aldosterone accelerates chronic kidney disease progression. This phase 2 clinical trial assessed BI 690517, an aldosterone synthase inhibitor, for efficacy, safety, and dose selection. METHODS: This was a multinational, randomised, controlled, phase 2 trial. People aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 30 to less than 90 mL/min/1·73 m2, a urine albumin to creatinine ratio (UACR) of 200 to less than 5000 mg/g, and serum potassium of 4·8 mmol/L or less, taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, were enrolled. Participants were randomly assigned (1:1) to 8 weeks of empagliflozin or placebo run-in, followed by a second randomisation (1:1:1:1) to 14 weeks of treatment with once per day BI 690517 at doses of 3 mg, 10 mg, or 20 mg, or placebo. Study participants, research coordinators, investigators, and the data coordinating centre were masked to treatment assignment. The primary endpoint was the change in UACR measured in first morning void urine from baseline (second randomisation) to the end of treatment. This study is registered with ClinicalTrials.gov (NCT05182840) and is completed. FINDINGS: Between Feb 18 and Dec 30, 2022, of the 714 run-in participants, 586 were randomly assigned to receive BI 690517 or placebo. At baseline, 33% (n=196) were women, 67% (n=390) were men, 42% (n=244) had a racial identity other than White, and mean participant age was 63·8 years (SD 11·3). Mean baseline eGFR was 51·9 mL/min/1·73 m2 (17·7) and median UACR was 426 mg/g (IQR 205 to 889). Percentage change in first morning void UACR from baseline to the end of treatment at week 14 was -3% (95% CI -19 to 17) with placebo, -22% (-36 to -7) with BI 690517 3 mg, -39% (-50 to -26) with BI 690517 10 mg, and -37% (-49 to -22) with BI 690517 20 mg monotherapy. BI 690517 produced similar UACR reductions when added to empagliflozin. Investigator-reported hyperkalaemia occurred in 10% (14/146) of those in the BI 690517 3 mg group, 15% (22/144) in the BI 690517 10 mg group, and 18% (26/146) in the BI 690517 20 mg group, and in 6% (nine of 147) of those receiving placebo, with or without empagliflozin. Most participants with hyperkalaemia did not require intervention (86% [72/84]). Adrenal insufficiency was an adverse event of special interest reported in seven of 436 study participants (2%) receiving BI 690517 and one of 147 participants (1%) receiving matched placebo. No treatment-related deaths occurred during the study. INTERPRETATION: BI 690517 dose-dependently reduced albuminuria with concurrent renin-angiotensin system inhibition and empagliflozin, suggesting an additive efficacy for chronic kidney disease treatment without unexpected safety signals. FUNDING: Boehringer Ingelheim.

Effect of medium cut-off and high-flux hemodialysis membranes on blood pressure assessed by ambulatory blood pressure monitoring.

BACKGROUND: Hypertension is one of the most critical risk factors for cardiovascular disease, which is the leading cause of death in hemodialysis (HD) patients. Medium cut-off (MCO) membrane increases the clearance of medium molecules, which could improve blood pressure (BP) control. This study aimed to compare the effect of MCO and high-flux hemodialysis membranes on BP assessed by ambulatory blood pressure monitoring (ABPM). METHODS: This is a pre-established secondary analysis of a 28-week, randomized, open-label crossover clinical trial. Patients were randomized to HD with MCO or high-flux membranes over 12 weeks, followed by a 4-week washout period, and then switched to the alternate membrane treatment for 12 weeks. ABPM was started before the HD session and ended at least 24 h later in weeks 1, 12, 16, and 28. RESULTS: 32 patients, 59% male, with a mean age of 52.7 years, and 40% with unknown CKD etiology, were enrolled. The dialysis vintage was 8 years, and more than 70% of the patients had hypertension. Regarding 24-h BP control, morning diastolic BP showed an increase in the high-flux compared to stability in the MCO group (interaction effect, p = 0.039). The adjusted ANOVA models showed no significant difference in the morning BP levels between the groups. Considering only the period of the HD session, patients in the MCO, compared to those in the high-flux membrane group, showed greater BP stability during dialysis, characterized by smaller variation in the pre-post HD systolic and minimum systolic BP (treatment effect, p = 0.039, and p = 0.023, respectively). CONCLUSIONS: MCO membrane seems to have a beneficial effect on morning BP and favors better BP stability during HD sessions.

Effect of Hemodialysis with Medium Cut-Off versus High-Flux Membranes on Endothelial Function of Patients with Chronic Kidney Disease.

INTRODUCTION: Endothelial dysfunction (ED) is considered a marker of vascular complications, especially in patients with end-stage kidney disease (ESKD). Inflammation and the uremic state contribute to ED in patients undergoing hemodialysis (HD). Recently, the medium cut-off (MCO) dialysis membrane has been proposed to efficiently remove inflammatory cytokines and large, middle-sized uremic toxins, with the potential effect to improve endothelial function. This study aimed to compare the effect of dialysis with MCO or high-flux membranes on the endothelial function of patients on chronic HD. METHODS: A prospective, randomized, crossover study in which 32 patients with ESKD were dialyzed for 12 weeks with each membrane, including a 4-week washout period between treatments. Endothelial function was assessed by flow-mediated dilation (FMD) using brachial artery ultrasound at weeks 1, 12, 16, and 28. RESULTS: The population consisted of 59% men, 52.7 ± 13.4 years, 16% non-black, on HD for 8.8 (4.1-15.1) years, and 72% with arteriovenous fistula. Hypertension was the most common etiology of chronic kidney disease, and 34% of patients had previous cardiovascular disease. Patients were grouped, regardless of treatment sequence, into MCO or high-flux groups, since no carryover (p = 0.634) or sequence (p = 0.998) effects were observed in the FMD assessment. The ANOVA model with repeated measures showed no effects of treatment (p = 0.426), time (p = 0.972), or interaction (p = 0.413) in the comparison of FMD between the MCO and high-flux groups. CONCLUSION: Dialysis performed with MCO, or high-flux membranes, had no influence on endothelial function in patients undergoing HD. However, a trend towards increased FMD was observed with the use of the MCO membrane.

Leptin Levels and Appetite Score in Patients on Hemodialysis Using High Flux or Medium Cutoff Membranes.

OBJECTIVES: Chronic kidney disease (CKD) patients on hemodialysis may have a modified appetite due to several factors including a lack of uremic toxins elimination. The use of medium cutoff (MCO) dialysis membranes has been suggested as an alternative to improve the removal of toxins, especially those of medium and high molecular weight. This study aimed to compare the effect of hemodialysis using MCO and high-flux membranes on the appetite and leptin levels of CKD patients. DESIGN AND METHODS: This is a predefined exploratory analysis of a randomized, open study, with a crossover design of 28 weeks of follow-up, which compared the effects of MCO and high-flux membranes in 32 CKD patients on hemodialysis. Appetite assessments were performed using the Appetite and Food Satisfaction Questionnaire. RESULTS: The MCO group had an appetite score of 3.00 (1.00-5.50) and 3.00 (1.00-5.00) at the beginning and at the end of the treatment period, respectively, while the high-flux group had 1.00 (0.25-6.00) and 2.00 (0.75-3.25). There were no effects of treatment (P = .573), time (P = .376), and interaction (P = .770) between the MCO and high-flux groups. Leptin levels, at the beginning and at the end of the treatment period, were 2,342.30 (1,156.50-4,091.50) and 2,571.50 (1,619.40-4,036.47) pg/mL in the MCO group, respectively, and 2,183.15 (1,550.67-3,656.50) and 2,685.65 (1,458.20-3,981.08) pg/mL in the high-flux group. There was a time effect (P = .014), showing an increase in leptin levels in both groups, while treatment (P = .771) or interaction (P = .218) effects were not observed. CONCLUSIONS: There is no difference between the effects of MCO or high-flux membranes on leptin levels or appetite of CKD patients on hemodialysis.

Characteristics and predictors of mortality on haemodialysis in Brazil: a cohort of 5,081 incident patients.

BACKGROUND: Although Brazil has one of the largest populations on haemodialysis (HD) in the world, data regarding patients' characteristics and the variables associated with risk of death are scanty. METHODS: This is a retrospective analysis of all adult patients who initiated on maintenance HD at 23 dialysis centres in Brazil between 2012 and 2017. Patients were censored after 60 months of follow-up or at the end of 2019. RESULTS: A total of 5,081 patients were included in the analysis. The median age was 59 years, 59.4% were men, 37.5% had diabetes as the cause of kidney failure. Almost 70% had a central venous catheter (CVC) as the initial vascular access, about 60% started dialysis in the hospital, and fluid overload (FO) by bioimpedance assessment was seen in 45% of patients. The 60-month survival rate was 51.4%. In the Cox regression analysis, being older (P<0.0001), starting dialysis in the hospital (P=0.016), having diabetes as the cause of kidney failure (P=0.001), high alkaline phosphatase (P=0.005), CVC as first vascular access (P=0.023), and FO (P<0.0001) were associated with higher death risk, whereas higher body mass index (P=0.015), haemoglobin (P=0.004), transferrin saturation (P=0.002), and serum albumin (P<0.0001) were associated with better survival. The same variables, except initial CVC use (P=0.14), were associated with death risk in an analysis of subdistribution proportional hazards ratio including the competing outcomes. CONCLUSIONS: The present study gives an overview of a large HD population in a developing country and identifies the main predictors of mortality, including some potentially modifiable ones, such as unplanned initiation of dialysis in the hospital and fluid overload.

Effect of fructooligosaccharide on endothelial function in CKD patients: a randomized controlled trial.

BACKGROUND: Microbiota-derived uremic toxins have been associated with inflammation that could corroborate with endothelial dysfunction (ED) and increase cardiovascular risk in patients with chronic kidney disease (CKD). This trial aimed to evaluate the effect of the prebiotic fructooligosaccharide (FOS) on endothelial function and arterial stiffness in nondialysis CKD patients. METHODS: In a double-blind controlled trial, 46 nondiabetic CKD patients were randomized to receive 12 g/day of FOS or placebo (maltodextrin) for 3 months. Total p-cresyl sulfate (PCS) and indoxyl sulfate by high-performance liquid chromatography, urinary trimethylamine N-oxide by mass spectrometry, C-reactive protein, interleukin-6 (IL-6), serum nitric oxide and stroma-derived factor-1 alfa were measured at baseline and at the end of follow-up; endothelial function was assessed through flow-mediated dilatation (FMD) and arterial stiffness by pulse wave velocity (PWV). RESULTS: The mean (± standard deviation) age of the study participants was 57.6 ± 14.4 years, with an estimated glomerular filtration rate of 21.3 ± 7.3 mL/min/1.73 m2. During the follow-up, regarding the inflammatory markers and uremic toxins, there was a significant decrease in IL-6 levels (3.4 ± 2.1 pg/mL versus 2.6 ± 1.4 pg/mL; P = 0.04) and a trend toward PCS reduction (55.4 ± 38.1 mg/L versus 43.1 ± 32.4 mg/L, P = 0.07) only in the prebiotic group. Comparing both groups, there was no difference in FMD and PWV. In an exploratory analysis, including a less severe ED group of patients (FMD ≥2.2% at baseline), FMD remained stable in the prebiotic group, while it decreased in the placebo group (group effect P = 0.135; time effect P = 0.012; interaction P = 0.002). CONCLUSIONS: The prebiotic FOS lowered circulating levels of IL-6 in CKD patients and preserved endothelial function only in those with less damaged endothelium. No effect of FOS in arterial stiffness was observed.

Effect of hemodiafiltration on measured physical activity: primary results of the HDFIT randomized controlled trial.

BACKGROUND: Dialysis patients are typically inactive and their physical activity (PA) decreases over time. Uremic toxicity has been suggested as a potential causal factor of low PA in dialysis patients. Post-dilution high-volume online hemodiafiltration (HDF) provides greater higher molecular weight removal and studies suggest better clinical/patient-reported outcomes compared with hemodialysis (HD). METHODS: HDFIT was a randomized controlled trial at 13 clinics in Brazil that aimed to investigate the effects of HDF on measured PA (step counts) as a primary outcome. Stable HD patients (vintage 3-24 months) were randomized to receive HDF or high-flux HD. Treatment effect of HDF on the primary outcome from baseline to 3 and 6 months was estimated using a linear mixed-effects model. RESULTS: We randomized 195 patients (HDF 97; HD 98) between August 2016 and October 2017. Despite the achievement of a high convective volume in the majority of sessions and a positive impact on solute removal, the treatment effect HDF on the primary outcome was +538 [95% confidence interval (CI) -330 to 1407] steps/24 h after dialysis compared with HD, and was not statistically significant. Despite a lack of statistical significance, the observed size of the treatment effect was modest and driven by steps taken between 1.5 and 24.0 h after dialysis, in particular between 20 and 24 h (+197 steps; 95% CI -95 to 488). CONCLUSIONS: HDF did not have a statistically significant treatment effect on PA 24 h following dialysis, albeit effect sizes may be clinically meaningful and deserve further investigation.

Soluble Fas affects erythropoiesis in vitro and acts as a potential predictor of erythropoiesis-stimulating agent therapy in patients with chronic kidney disease.

Serum soluble Fas (sFas) levels are associated with erythropoietin (Epo) hyporesponsiveness in patients with chronic kidney disease (CKD). Whether sFas could predict the need for erythropoiesis-stimulating agent (ESA) usage and its influence in erythropoiesis remain unclear. We evaluated the relation between sFas and ESA therapy in patients with CKD with anemia and its effect on erythropoiesis in vitro. First, we performed a retrospective cohort study with 77 anemic patients with nondialysis CKD. We performed in vitro experiments to investigate whether sFas could interfere with the behavior of hematopoietic stem cells (HSCs). HSCs were isolated from umbilical cord blood and incubated with recombinant sFas protein in a dose-dependent manner. Serum sFas positively correlated with Epo levels (r = 0.30, P = 0.001) but negatively with hemoglobin (r = -0.55, P < 0.001) and glomerular filtration rate (r = -0.58, P < 0.001) in patients with CKD at baseline. Elevated sFas serum levels (4,316 ± 897 vs. 2,776 ± 749, P < 0.001) with lower estimated glomerular filtration rate (26.2 ± 10.1 vs. 33.5 ± 14.3, P = 0.01) and reduced hemoglobin concentration (11.1 ± 0.9 vs. 12.5 ± 1.2, P < 0.001) were identified in patients who required ESA therapy compared with patients with non-ESA. Afterward, we detected that the sFas level was slight correlated with a necessity of ESA therapy in patients with nondialysis CKD and anemia. In vitro assays demonstrated that the erythroid progenitor cell frequency negatively correlated with sFas concentration (r = -0.72, P < 0.001). There was decreased erythroid colony formation in vitro when CD34+ HSCs were incubated with a higher concentration of sFas protein (1.56 ± 0.29, 4.33 ± 0.53, P < 0.001). Our findings suggest that sFas is a potential predictor for ESA therapy in patients with nondialysis CKD and that elevated sFas could affect erythropoiesis in vitro.

Effect of Hemodiafiltration on Self-Reported Sleep Duration: Results from a Randomized Controlled Trial.

INTRODUCTION: Dialysis patients suffer from poor sleep duration and quality. We examined the self-reported sleep duration in patients randomized to either high-volume hemodiafiltration (HDF) or high flux hemodialysis (HD). METHODS: Patients from 13 Brazilian dialysis clinics were enrolled in the HDFIT randomized controlled trial (RCT) investigating the impact of HDF on physical activity and self-reported outcomes. Self-reported sleep duration was taken from patient diaries recording sleep start and end time over a week during baseline, months 3 and 6, respectively. Sleep duration was analyzed by shift and nights relative to dialysis. RESULTS: The HDFIT study enrolled 197 patients; sleep data were available in 173 patients (87 HD; 86 HDF). Patients' age was 53 ± 15 years, 57% were white, 72% were male, 34% had diabetes, Kt/V was 1.54 ± 0.40, and albumin 3.97 ± 0.36 g/dL. Most patients reported sleeping 510-530 min/night. At 3 months, HDF patients slept 513 ± 71 min/night, HD patients 518 ± 76 min/night. At 6 months, HDF patients slept 532 ± 74 min/night, HD patients 519 ± 80 min/night. At baseline, 1st shift patients slept 406 ± 86 min the night before HD, 534 ± 64 min the night after HD, and 496 ± 99 min the night between 2 non-HD days. Compared to patients in the 2nd and 3rd shifts, patients dialyzed in the 1st shift slept less in the night before dialysis. Similar patterns were seen after 3 and 6 months. CONCLUSION: In our RCT, the dialysis modality (HDF vs. HD) had no effect on self-reported sleep duration. In both groups, dialysis in the 1st shift adversely affected self reported sleep duration.

Patient perception of vitality and measured physical activity in patients receiving haemodialysis.

AIM: Fatigue in haemodialysis (HD) patients can be captured in quality of life questionnaires and by the dialysis recovery time (DRT) question. The associations between fatigue and measured physical activity has not been explored until the present. We tested our hypothesis that the patient perception of chronic and post dialysis fatigue would be associated with lower physical activity. METHODS: This study was a cross sectional evaluation of baseline data from HD patients recruited in the HDFIT trial. Vitality scores from the Kidney Disease Quality of Life (KDQOL-36) and the dialysis recovery time (DRT) question were used as indicators of chronic and post dialysis fatigue, respectively. Granular physical activity was measured by accelerometers as part of the study protocol. RESULTS: Among 176 patients, Vitality score was 63 ± 21 and the DRT was ≤30 minutes in 57% of patients. The mean number of steps was 5288 ± 3540 in 24 hours after HD and 953 ± 617 in the 2-hour post-HD period. The multivariable analysis confirmed Vitality scores were associated with physical activity in the 24-hour post-HD period. In contrast, DRT was not associated with physical activity captured by the accelerometer in the period immediately (2 hours) after the HD session. CONCLUSION: Chronic fatigue was negatively associated with step counts, while patient perception of post-dialysis fatigue was not associated with physical activity. These patterns indicate limitations in interpretation of DRT. Since physical activity is an important component of a healthy life, our results may partially explain the associations between fatigue and poor outcomes in HD patients.

Cortical unlike trabecular bone loss is not associated with vascular calcification progression in CKD patients.

BACKGROUND: Vascular calcification progression has been associated with the loss of trabecular bone in chronic kidney disease (CKD) patients. There are few data evaluating the relationship between cortical bone loss and vascular calcification in this population. The aim of this study was to prospectively evaluate the association between changes in cortical bone density and coronary artery calcification (CAC) progression in non-dialyzed CKD patients. METHODS: Changes of cortical and trabecular bone, and changes of calcium score, were analyzed using vertebral tomographic images from a prospective study. Automatic delineation of the cortical bone layer was performed by Image J software, and trabecular bone was determined by selecting a region of interest using Vitrea 2® software. Cortical and trabecular bone density (BD) were expressed in Hounsfield Units (HU), and coronary artery calcium score in Agatston Units (AU). RESULTS: Seventy asymptomatic patients [57.8 ± 10.2 years, 63% males, 20% diabetic, estimated glomerular filtration rate (eGFR) = 37.3 (24.8-51.3) mL/min/1.73m2] were followed for 24 months. The mean cortical and trabecular BD did not change over time. While 49 patients lost either bone, 29 (41%) patients lost cortical [- 4.4%/year (ranging from - 7.15 to - 0.5)] and 39 (56%) lost trabecular bone [- 3.15%/year (- 13.7 to - 0.25)]. There was no association between cortical and trabecular BD changes (p = 0.12). CAC was observed in 33 (46%) patients at baseline, and 30 (91%) of them showed CAC progression. While an inverse correlation between trabecular bone and calcium score changes was observed (p = 0.001), there was no correlation between cortical bone and calcium score changes (p = 0.34). CONCLUSION: CKD patients experience either cortical or trabecular bone loss over time, but these changes do not take place simultaneously in all patients. Cortical, unlike trabecular bone loss, is not associated with vascular calcification progression in these patients.

Impact of hemodialysis and post-dialysis period on granular activity levels.

BACKGROUND: Physical activity (PA) is typically lower on hemodialysis (HD) days. Albeit intradialytic inactivity is expected, it is unknown whether recovery after HD contributes to low PA. We investigated the impact of HD and post-HD period on granular PA relative to HD timing. METHODS: We used baseline data from the HDFIT trial conducted from August 2016 to October 2017. Accelerometry measured PA over 1 week in patients who received thrice-weekly high-flux HD (vintage 3 to 24 months), were clinically stable, and had no ambulatory limitations. PA was assessed on HD days (0 to ≤24 h after start HD), first non-HD days (> 24 to ≤48 h after start HD) and second non-HD day (> 48 to ≤72 h after start HD). PA was recorded in blocks/slices: 4 h during HD, 0 to ≤2 h post-HD (30 min slices), and > 2 to ≤20 h post-HD (4.5 h slices). Blocks/slices of PA were captured at concurrent/parallel times on first/second non-HD days compared to HD days. RESULTS: Among 195 patients (mean age 53 ± 15 years, 71% male), step counts per 24-h were 3919 ± 2899 on HD days, 5308 ± 3131 on first non-HD days (p < 0.001), and 4926 ± 3413 on second non-HD days (p = 0.032). During concurrent/parallel times to HD on first and second non-HD days, patients took 1308 and 1128 more steps (both p < 0.001). Patients took 276 more steps and had highest rates of steps/hour 2-h post-HD versus same times on first non-HD days (all p < 0.05). Consistent findings were observed on second non-HD days. CONCLUSIONS: PA was higher within 2-h of HD versus same times on non-HD days. Lower PA on HD days was attributable to intradialytic inactivity. The established PA profiles are of importance to the design and development of exercise programs that aim to increase activity during and between HD treatments. TRIAL REGISTRATION: HDFIT was prospectively registered 20 April 2016 on ClinicalTrials.gov (NCT02787161).

Bowel Habits and the Association With Uremic Toxins in Non-Dialysis-Dependent Chronic Kidney Disease Patients.

OBJECTIVE: The aim of this study is to evaluate the association between bowel habits and microbial-derived uremic toxins p-cresyl sulfate (PCS) and indoxyl sulfate (IS) in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). DESIGN AND METHODS: This is a cross-sectional analysis including 43 nondiabetic NDD-CKD patients (58% men; 59.0 ± 13.5 years; estimated glomerular filtration rate, 21.3 ± 7.9 mL/min/1.73 m2). Bowel habit was assessed by the Bristol Stool Scale (BSS <3, characterized by hard consistency of stools and/or low frequency of evacuation and BSS ≥3, representing a more regular bowel habit) and by the Rome III criteria. PCS and IS (serum, free and total; urinary, total) were determined by high-performance liquid chromatography. Dietary intake was assessed by the 3-day food records. RESULTS: The frequency of constipation assessed by BSS and Rome III criteria was 33% (n = 14/43) and 35% (n = 15/43), respectively. The BSS <3 exhibited higher PCS, independent of renal function and dietary protein-fiber ratio (ß [95% confidence interval {CI}]: serum, total PCS = 1.54 [1.06-2.23], P = .02; serum free PCS = 1.40 [1.00-1.97], P = .05; urinary PCS = 1.78 [1.10-2.90], P < .02). According to the Rome III criteria, a tendency for a higher serum total PCS (ß [95% CI]: 1.39 [0.95-2.03 µmol/L], P = .09) and a significantly higher urinary PCS (ß [95% CI]: 1.80 [1.11-2.94 µmol/24 h], P = .02) was found in constipated participants. No effect of a compromised bowel habit (Rome III criteria or BSS) was found on IS. CONCLUSION: Constipation may lead to production of PCS in nondiabetic NDD-CKD patients.

Effect of prebiotic (fructooligosaccharide) on uremic toxins of chronic kidney disease patients: a randomized controlled trial.

BACKGROUND: Microbial-derived uremic toxins, p-cresyl sulfate (PCS), indoxyl sulfate (IS) and indole 3-acetic acid (IAA), have been associated with the burden of chronic kidney disease (CKD). Prebiotics have emerged as an alternative to modulate the gut environment and to attenuate toxin production. This trial aims to investigate the effect of a prebiotic fructooligosaccharide (FOS) on uremic toxins of non-dialysis-dependent CKD (NDD-CKD) patients. METHODS: A double-blind, placebo-controlled, randomized trial was conducted for 3 months. In all, 50 nondiabetic NDD-CKD patients [estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m2], aged 18-80 years, were allocated to prebiotic (FOS, 12 g/day) or placebo (maltodextrin, 12 g/day) groups. Primary outcomes were changes in serum (total and free) and urinary (total) PCS. Secondary outcomes included changes in IS, IAA, serum markers of intestinal permeability (zonulin), gut-trophic factors (epidermal growth factor and glucagon-like peptide-2), eGFR, inflammation (high sensitive c-reactive protein and interleukin-6), homeostatic model assessment-insulin resistance, lipid profile and gastrointestinal symptoms. RESULTS: From 50 participants (54% men, 57.3 ± 14.6 years and eGFR 21.4 ± 7.6 mL/min/1.73 m2), 46 completed the follow-up. No changes in dietary intake or gastrointestinal symptoms were observed. There was a trend in the difference of serum total ΔPCS (treatment effect adjusted for baseline levels: -12.4 mg/L; 95% confidence interval (-5.6 to 0.9 mg/L; P = 0.07) and serum-free Δ%PCS [intervention -8.6 (-41.5 to 13.9%) versus placebo 3.5 (-28.8 to 85.5%); P = 0.07] between the groups. The trend in the difference of serum total ΔPCS was independent of eGFR and dietary protein:fiber ratio intake. No difference was found in urinary PCS. Aside from the decreased high-density lipoprotein cholesterol in the intervention, no differences were observed in the change of IS, IAA or other secondary outcome between the groups. CONCLUSIONS: Our result suggests the potential of FOS in reducing serum total and free PCS in nondiabetic NDD-CKD patients.

Design and methodology of the impact of HemoDiaFIlTration on physical activity and self-reported outcomes: a randomized controlled trial (HDFIT trial) in Brazil.

BACKGROUND: End stage renal disease (ESRD) patients require a renal replacement therapy (RRT) to filter accumulated toxins and remove excess water, which are associated with impaired physical function. Hemodialysis (HD) removes middle-molecular weight (MMW) toxins less efficiently compared to hemodiafiltration (HDF); we hypothesized HDF may improve physical function. We detailed the design and methodology of the HDFIT protocol that is testing whether changing from HD to HDF effects physical activity levels and various outcomes. METHODS: HDFIT is a prospective, multi-center, unblinded, randomized control trial (RCT) investigating the impact of dialysis modality (HDF verses HD) on objectively measured physical activity levels, self-reported quality of life, and clinical/non-clinical outcomes. Clinically stable patients with HD vintage of 3 to 24 months without any severe limitation ambulation were recruited from sites throughout southern Brazil. Eligible patients were randomized in a 1:1 ratio to either: 1) be treated with high volume online HDF for 6 months, or 2) continue being treated with high-flux HD. This study includes run-in and randomization visits (baseline), 3- and 6-month study visits during the interventional period, and a 12-month observational follow up. The primary outcome is the difference in the change in steps per 24 h on dialysis days from baseline to the 6-month follow up in patients treated with HDF versus HD. Physical activity is being measured over one week at study visits with the ActiGraph ( www.actigraphcorp.com ). For assessment of peridialytic differences during the dialysis recovery period, we will analyze granular physical activity levels based on the initiation time of HD on dialysis days, or concurrent times on non-dialysis days and the long interdialytic day. DISCUSSION: In this manuscript, we provide detailed information about the HDFIT study design and methodology. This trial will provide novel insights into peridialytic profiles of physical activity and various self-reported, clinical and laboratory outcomes in ESRD patients treated by high volume online HDF versus high-flux HD. Ultimately, this investigation will elucidate whether HDF is associated with patients having better vitality and quality of life, and less negative outcomes as compared to HD. TRIAL REGISTRATION: Registered on ClinicalTrials.gov on 20 April 2016 ( NCT02787161 ).

The Effect of Long-Term Cholecalciferol Supplementation on Vascular Calcification in Chronic Kidney Disease Patients With Hypovitaminosis D.

OBJECTIVE: The role of vitamin D supplementation on vascular calcification (VC) in patients with chronic kidney disease (CKD) is controversial. The objective of this study was to evaluate the effects of long-term cholecalciferol supplementation on VC in nondialysis patients with CKD stages 3-4 with hypovitaminosis D. DESIGN AND METHODS: Eighty patients aged 18-85 years with creatinine clearance between 15 and 60 mL/min/1.73 m2 and serum 25(OH)D level < 30 ng/mL were enrolled in a 18-month prospective study. Individuals with vitamin D insufficiency (25-hydroxyvitamin D [25(OH)D] level between 16 and 29 ng/mL) were included in a randomized, double-blind, two-arm study to receive cholecalciferol or placebo. Patients with vitamin D deficiency [25(OH)D < 15 ng/mL] were included in an observational study and mandatorily received cholecalciferol. The coronary artery calcium score was obtained by multislice computed tomography at baseline and the 18th month. RESULTS: During the study, VC did not change in the treated insufficient group (418 [81-611] to 364 [232-817] AU, P = 0.25) but increased in the placebo group (118 [37-421] to 199 [49-490] AU, P = 0.01). The calcium score change was inversely correlated with 25(OH)D change (r = -0.45; P = 0.037) in the treated insufficient group but not in the placebo group. Renal function did not change in the insufficient, treated, and placebo groups. In multivariate analysis, there was no difference in VC progression between the treated and placebo insufficient groups (interaction P = 0.92). In the deficient group, VC progressed (265 [84-733] to 333 [157-745] AU; P = 0.006) and renal function declined (33 [26-43] to 23 [17-49] mL/min/1.73 m2; P = 0.04). The calcium score change was inversely correlated with cholecalciferol cumulative doses (r = -0.41; P = 0.048) and kidney function change (r = -0.43; P = 0.033) but not with 25(OH)D change (r = -0.08; P = 0.69). CONCLUSION: Vitamin D supplementation did not attenuate VC progression in CKD patients with hypovitaminosis D. CONCLUSION: Vitamin D supplementation did not attenuate VC progression in CKD patients with hypovitaminosis D.

Obstructive sleep apnea is associated with interdialytic weight gain and increased long-term cardiovascular events in hemodialysis patients.

BACKGROUND: Obstructive sleep apnea (OSA) is common in hemodialysis (HD) patients. The reasons for the high prevalence and whether OSA is associated with vascular impairment, end-organ damage, and prognosis are not completely clear. METHODS: We evaluated patients with low cardiovascular risk on HD, not treated by CPAP. Laboratory tests, sleep questionnaires (Berlin and Epworth) and polysonography studies, echocardiography, and markers of arterial stiffness and atherosclerosis were performed. After the initial evaluation, patients were followed up until cardiovascular events, renal transplantation, or death. RESULTS: Fifty-five patients (49% male, 50 ± 9 years, body mass index 24.7 ± 4.5 kg/m2) were included. OSA (apnea-hypopnea index ≥ 5 events/h) occurred in 73% of the patients. The proportion of patients with interdialytic weight gain > 2 kg was higher in patients with OSA than those without OSA (96 vs. 55%; p = 0.002). Left ventricular (LV) posterior wall thickness (10.0 ± 1.9 vs. 11.3 ± 1.8 mm; p = 0.04) and LV diastolic diameter (48 ± 5 vs. 53 ± 5 mm; p = 0.003) were higher in patients with OSA than in patients without OSA, respectively. Sleep questionnaires did not predict OSA. No significant differences were found in pulse wave velocity, carotid intima-media thickness, and ankle-brachial index between the groups. Multivariate analysis showed that interdialytic weight gain > 2 kg and LV diastolic diameter were independently associated with OSA. On follow-up (median 45 months), OSA was found to be associated with a higher incidence of cardiovascular (CV) events (28 vs. 7%, log-rank = 0.042). CONCLUSIONS: OSA was associated with increased risk of CV events. Significant (> 2 kg) interdialytic weight gain was independently associated with OSA.

Apolipoprotein E polymorphism modulation of asymmetric dimethylarginine in hypertensive patients is determined by renal function.

BACKGROUND: Endothelial dysfunction is considered an early step of atherosclerotic vascular disease. Asymmetric dimethylarginine (ADMA), the main endogenous inhibitor of nitric oxide synthase (NOS), plays a critical role in the process of atherosclerosis in a uremic environment. Increased plasma ADMA not only works as a cardiovascular morbidity biomarker but it is also involved in the genesis of atherosclerosis in renal disease. Considering the relationships of apolipoprotein E(ApoE) polymorphism with LDL cholesterol (LDL-C) levels and coronary risk, it is possible that it brings on susceptibility to endothelial dysfunction and atherogenesis seen on uremia. METHODS: Six hundred twenty patients were stratified according to glomerular filtration rate (GFR) estimated by Chronic Kidney Disease Epidemiology Collaboration (CKDEPI) formula: group I > 60 mL/min, group II ≤ 60 mL/min and > 15 mL/min, and group III ≤ 15 mL/min or in hemodialysis. Polymorphic ApoE analysis was performed by polymerase chain reaction amplification (PCR). Plasma ADMA levels were measured by high performance liquid chromatography (HPLC). Groups were compared on clinical and laboratory characteristics as well as allele and genotype distribution towards. RESULTS: The ε2 allele of ApoE was present in 62 (10.3 %) patients, ε3 allele in 581 (96.2 %), and ε4 allele in 114 (18.9 %). Their distribution among the 3 groups was uniform. Such uniformity was not observed when we considered endothelial function measured by asymmetric dimethylarginine. In group III, the frequency of ε4 allele was significantly lower in the third tertile compared with the first tertile (14.7 versus 53.3 %, P = 0.000; Pearson chi-square). In groups I and II, there was no difference in allele frequency according to ADMA levels. This association remained significant even after confouding factors corrections (OR 0.329, 95 % CI 0.155 - 0.699, P = 0.004). CONCLUSIONS: The results of this study shows that the frequency of ε4 allele of ApoE is significantly lower among hypertensive patients on hemodialysis with the highest levels of ADMA. Uremia is capable of determining lower plasma ADMA levels in hypertensive ε4 allele carriers.

Icodextrin reduces insulin resistance in non-diabetic patients undergoing automated peritoneal dialysis: results of a randomized controlled trial (STARCH).

BACKGROUND: Insulin resistance is a common risk factor in chronic kidney disease patients contributing to the high cardiovascular burden, even in the absence of diabetes. Glucose-based peritoneal dialysis (PD) solutions are thought to intensify insulin resistance due to the continuous glucose absorption from the peritoneal cavity. The aim of our study was to analyse the effect of the substitution of glucose for icodextrin on insulin resistance in non-diabetic PD patients in a multicentric randomized clinical trial. METHODS: This was a multicenter, open-label study with balanced randomization (1:1) and two parallel-groups. Inclusion criteria were non-diabetic adult patients on automated peritoneal dialysis (APD) for at least 3 months on therapy prior to randomization. Patients assigned to the intervention group were treated with 2L of icodextrin 7.5%, and the control group with glucose 2.5% during the long dwell and, at night in the cycler, with a prescription of standard glucose-based PD solution only in both groups. The primary end-point was the change in insulin resistance measured by homeostatic model assessment (HOMA) index at 90 days. RESULTS: Sixty patients were included in the intervention (n = 33) or the control (n = 27) groups. There was no difference between groups at baseline. After adjustment for pre-intervention HOMA index levels, the group treated with icodextrin had the lower post-intervention levels at 90 days in both intention to treat [1.49 (95% CI: 1.23-1.74) versus 1.89 (95% CI: 1.62-2.17)], (F = 4.643, P = 0.03, partial η(2) = 0.078); and the treated analysis [1.47 (95% CI: 1.01-1.84) versus 2.18 (95% CI: 1.81-2.55)], (F = 7.488, P = 0.01, partial η(2) = 0.195). CONCLUSIONS: The substitution of glucose for icodextrin for the long dwell improved insulin resistance measured by HOMA index in non-diabetic APD patients.

High volume online hemodiafiltration: a global perspective and the Brazilian experience.

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.