Cohort Of Peritoneal Dialysis Patients Research Articles

#2103 Accuracy of a continuous glucose monitor in people with diabetes on peritoneal dialysis

Abstract Background and Aims Globally 40% of people receiving peritoneal dialysis (PD) have a diagnosis of diabetes. Good glycaemic control can by complicated by the obligate glucose load associated with PD. Monitoring and treatment of people with diabetes (PwD) on PD has been limited by reduced reliability of traditional markers of glycaemia such as HbA1c in end-stage kidney disease. Continuous glucose monitors (CGMs) have been increasingly used in the care of PwD over the last 20 years. Monitors worn on the upper arm or abdomen measure glucose in interstitial fluid at regular intervals over the 24 hour period. CGMs are currently unlicensed in PD populations as they have not been tested in large scale studies. Concerns remain around accuracy in the presence of potentially interfering substances generated by the breakdown of osmotic agents used in PD fluid (e.g. Icodextrin). We aimed to assess the analytical and clinical accuracy of the FreeStyle Libre(FSL) CGM system in PwD on maintenance PD. Method We conducted a single centre observational study of 10 PwD who had been on PD for at least 3 months. For the 10 day study period participants wore a blinded research model FSL monitor which measured interstitial glucose levels every 15 minutes. Results from the FSL were compared with; Analytical accuracy was assessed using three methods; Clinical accuracy was assessed using the Parkes consensus error grid to assign each pair of readings to one of five risk zones and quantify the clinical implications of any difference between the two measurements. The International Organisation for Standardisation guidelines stipulates 99% of pairs should be in zones A and B, denoting little or no effect on clinical actions. Results Of 11 recruited participants, 10 completed the 10 day study period resulting in 76 paired CGM-YSI measurements and 375 paired CGM-CBG measurements. 7 participants were on APD and 3 on CAPD. All participants were prescribed a PD regime that included one daily dwell with Icodextrin. The aggregate MARD was 9.4% (95% CI 7.9, 10.4) for CGM-YSI matched pairs and 17.6% (95% CI 17, 19.3) for CGM-CBG matched pairs. Spearman's r was 0.94 (p < 0.0001) for CGM-YSI and 0.89 (p < 0.0001) for CGM-CBG. From Bland-Altman analysis, the systematic error of the CGM compared with YSI and CBG was −0.81 mmol/l (SD 0.81) and −1.6 mmol/l (SD 1.9) respectively. Parkes consensus error grid analysis showed that compared with YSI and CBG respectively, 100% and 99.9% of sensor values were in the clinically acceptable zones A and B (Fig. 1). Conclusion We have demonstrated satisfactory performance of the FSL monitoring system by both analytical and clinical metrics in this cohort of PD patients using treatment regimens including Icodextrin based fluids. CGMs provide much more information for the PwD and their clinical care team compared with random CBGs (which in themselves have been shown to exhibit significant between user variability) and time averaged markers such as HbA1c. They allow detection of asymptomatic hypoglycaemia and direct monitoring of the systemic effects of any change to the PD prescription resulting in a larger or smaller glucose load. These results should be reassuring for clinicians wishing to utilise the greater depth of information provided by CGMs to improve clinical care for their patients with diabetes on PD.

Attention-Based Deep Learning Model for Prediction of Major Adverse Cardiovascular Events in Peritoneal Dialysis Patients.

Major adverse cardiovascular events (MACE) encompass pivotal cardiovascular outcomes such as myocardial infarction, unstable angina, and cardiovascular-related mortality. Patients undergoing peritoneal dialysis (PD) exhibit specific cardiovascular risk factors during the treatment, which can escalate the likelihood of cardiovascular events. Hence, the prediction and key factor analysis of MACE have assumed paramount significance for peritoneal dialysis patients. Current pathological methodologies for prognosis prediction are not only costly but also cumbersome in effectively processing electronic health records (EHRs) data with high dimensionality, heterogeneity, and time series. Therefore in this study, we propose the CVEformer, an attention-based neural network designed to predict MACE and analyze risk factors. CVEformer leverages the self-attention mechanism to capture temporal correlations among time series variables, allowing for weighted integration of variables and estimation of the probability of MACE. CVEformer first captures the correlations among heterogeneous variables through attention scores. Then, it analyzes the correlations within the time series data to identify key risk variables and predict the probability of MACE. When trained and evaluated on data from a large cohort of peritoneal dialysis patients across multiple centers, CVEformer outperforms existing models in terms of predictive performance.

Comorbidity and in-hospital mortality in peritoneal dialysis patients: data of the Emilia Romagna region of Italy.

Kidney failure increases in-hospital mortality (IHM); however, comorbidity is crucial for predicting mortality in dialysis patients. Our aim was to evaluate the impact of comorbidity, assessed by modified Elixhauser index (mEI), Charlson Comorbidity Index (CCI), and age-adjusted CCI, on IHM in a cohort of peritoneal dialysis patients admitted to hospitals of the Emilia Romagna region (ERR) of Italy. All hospital admissions of peritoneal dialysis patients recorded between 2007 and 2021 in the ERR database were analyzed. The International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) was used for detecting diagnoses and procedures, and the inclusion criterion was code 5498. Comorbidity burden was evaluated by three different scores, and hemodialysis (HD) treatment need was considered. IHM was our outcome. During the 15 years of the study, 3,242 hospitalized peritoneal dialysis patients (62.7% males) were evaluated. Mean age was 62.8±20.6 years, 9.6% underwent HD, and IHM was 5.9% (n=192). IHM mortality was stable throughout the study period. Deceased subjects were older, were hospitalized longer, had a higher comorbidity burden, and had a higher percentage of HD treatment needs than survivors. Age, male sex, comorbidity burden, and HD treatment were predictors of IHM. Receiver operating characteristics (ROC) analysis confirmed the impact of comorbidity burden on IHM, especially when age was considered. We conclude that in male, elderly hospitalized peritoneal dialysis patients with failing dialysis technique, comorbidity burden should be considered being a predictor of IHM.

Peritoneal dialysis related non-infectious complications: Asingle-center experience over 20 years.

Non-infectious complications of peritoneal dialysis (NICPD) are common and could be an important cause of technical failure, especially in the early period of peritoneal dialysis (PD) initiation. NICPD are also center- and provider-dependent. This study aimed to investigate the frequency, etiology, and associated outcomes of NICPD in a single center over a period of 20 years. Data were retrospectively collected in 262 patients who were initiated on PD between April 2001 and April 2021. Inclusion criteria were age 18 years or older and a minimum follow-up period of 3 months. Patients were grouped according to the reason of NICPD: catheter-related, increased intra-abdominal pressure-related, metabolic, and other complications. There were 142 females and 120 males in the study, with a mean age of 44±16.9 years. The mean time on PD was 52.6±40 months. During the follow-up period, 185 (71%) patients experienced 382 NICPD episodes. 26 patients (9.9%) were switched to maintenance hemodialysis (HD) due to NICPD. Outflow failure was the most common NICPD (n=97). It was also the most common reason for catheter revision (n=23) and PD discontinuation (n=12). Catheter intervention was required in 32 patients (12.2%). Prior HD treatment and male gender were independent risk factors for NICPD and catheter-related complications (OR 2.076; p=0.037; OR: 1.797, p=0.042, respectively). Early-start PD was associated with a lower risk for NICPD development (OR: 0.393, p=0.013). In this select cohort of PD patients, we found that NICPD are common and outflow failure is the most common cause of NICPD. NICPD are associated with major complications requiring catheter removal or transfer to in-center HD. Early recognition and appropriate management of NICPD are essential to prolonging time on PD in end-stage renal disease patients.

#4905 PERITONEAL CLEARANCE OF TRACE ELEMENTS IN PERITONEAL DIALYSIS PATIENTS

Abstract Background and Aims Both accumulations and deficiencies of trace elements (TE) could be seen in peritoneal dialysis (PD) patients. Peritoneal clearance remains major route of elimination for many solutes including TE, in PD patients. Imbalances of TE may have deleterious effects on the patients. Data on TE balances in PD patients are inadequate. Here, we present some data from a larger study. We aimed to analyze peritoneal clearance of Boron (B), Cupper (Cu), Zinc (Zn), Selenium (Se), Strontium (Sr) and Molybdenum (Mo) in a cohort of PD patients. Method This cross-sectional study included three female and five male PD patients giving consent for the study. Mean age was 43,6±5,6 and patients were on continuous ambulatory PD for at least three months. Patients with recent peritonitis were excluded. Peritoneal solutions were individualized, so had different osmolarities. A sample of plasma and 24-hour spent dialysate was analyzed by inductively coupled plasma mass spectrometry (ICP-MS) (Thermo Scientific™ iCAP Q ICP-MS, USA). Sensitivity was on the order of ppb (μg/L). A control group (CG) with glomerular filtration rate ≥ 90 ml/min were used for comparison of plasma levels of TE. Peritoneal clearances were calculated by the following formula: ${{24 \!-\! hour \, spent\, dialysate\, volume \!\times\! \displaystyle\frac{{dialysate\ concentration\ of\ the\ trace\ element}}{{plasma\ concentration\ of\ the\ trace\ element}}}}$ Results Data on plasma levels, clearances and daily loss of TE are shown in the Table 1. The clearances were ordered from smallest to largest as follows: Zn, Cu, Se, Sr, Mo, Ni, B. On the other hand, spent dialysate daily element losses were ordered from smallest to highest as follows: Cr, Ni, Se, Mo, Cu, Sr, Zn, B Conclusion Our study provides data on elimination of some trace elements, which may help to better understand the TE balance in PD patients. Data suggest that B has the highest and Zn the lowest peritoneal clearance values.

#4387 LIQUID BIOPSY IN PATIENTS TREATED WITH BIOCOMPATIBLE PERITONEAL DIALYSIS FLUIDS – ITS RELATIONSHIP WITH CYTOLOGICAL AND HISTOLOGICAL FINDINGS

Abstract Background and Aims Peritoneal fibrosis can limit long term peritoneal membrane function in peritoneal dialysis (PD) patients. It has been related to bioincompatible PD fluids and peritoneal infections. There are no prospective studies regarding correlation between effluent biomarkers and peritoneal biopsy findings. Our aim was to study the possible relation of peritoneal effluent biomarkers and peritoneal morphology alterations. Method Multicenter prospective study in a cohort of stable PD patients treated with biocompatible PD fluids who received a kidney transplant. We collected in each patient peritoneal biopsy samples and peritoneal effluent fluid. We analyzed the relation between effluent biomarkers, phenotype of mesothelial cells (MC) cultured ex vivo, and peritoneal biopsy parameters (mesothelial integrity, fibrosis and hyalinizing vasculopathy). We compared them with patient characteristics, including peritoneal transport parameters. The biomarkers tested were Collagen-1 (COL-1), Fibronectin (FN), Collagen-13 (COL-13), Interleukin-6 (IL-6), Trombospondin-1, Cadherin 13 (CDH-13), CA-125, Gremlin-1 (GREM-1), Matrix metalloproteinase 2 (MMP-2), CC chemokine ligand 18 (CCL18), Plasminogen activator inhibitor 1 (PAI-1) and Vascular endothelial growth factor A (VEGF-A). Results Forty patients were included (mean age 54.5±15 years, 64% male, 24.1% diabetics). Mean time on PD was 25.5±27 months, 62.1% were on automated PD (APD) and 17.2% had prior peritonitis episodes. A normal MC culture phenotype was observed in 78% of patients. In peritoneal biopsies samples we found partial or total mesothelium preservation in 39%, submesothelial thickness in 42% and vasculopathy in 14% of cases. Effluent PAI-1 levels were significantly lower in patients with mesothelial cell loss than in those with mesothelial preservation (21.62 vs. 38.59 pg/ml respectively; p = 0.031). Patients with peritoneal fibrosis showed significantly higher effluent CDH-13 levels (3.51 vs. 2.32 pg/ml; p = 0.048) and supernatant PAI-1 levels (1183 vs. 72.73; p = 0.000) than those without fibrosis. No other statistical differences were found in other biomarkers analysed. Conclusion Most patients treated with biocompatible peritoneal dialysis fluids showed normal mesothelial cell phenotype in peritoneal effluent culture. Lower PAI-1 effluent levels were associated with mesothelial cell loss and higher effluent CDH-13 levels were related to peritoneal fibrosis.

Outcomes of COVID-19 in peritoneal dialysis patients: A report by the European Renal Association COVID-19 Database

The clinical course of COVID-19 in peritoneal dialysis (PD) patients has so far only been analysed in relatively small, often single-centre case series. Therefore, we studied patient- and disease-related characteristics and outcomes of COVID-19 in a larger European cohort of PD patients. We used data from the European Renal Association COVID-19 Database (ERACODA) on PD and haemodialysis (HD) patients with COVID-19 (presentation between February 2020 and April 2021). Hazard ratios (HR) for mortality at 3 months were calculated using Cox proportional-hazards regression. In addition, we examined functional and mental health status among survivors at this time point as determined by their treating physician. Of 216 PD patients with COVID-19, 80 (37%) were not hospitalised and 136 (63%) were hospitalised, of whom 19 (8.8%) were admitted to an intensive care unit. Mortality at 3 months for these subgroups was 18%, 40%, and 37%, respectively (p = 0.0031). Compared with HD patients, PD patients had higher mortality (crude HR: 1.49; 95% CI: 1.33-1.66), even when adjusted for patient characteristics and disease severity (adjusted HR: 1.56; 95% CI: 1.39-1.75). Follow-up data on 67 of 146 patients who survived COVID-19 showed functional recovery to pre-COVID-19 levels in 52 (78%) and mental recovery in 58 patients (87%) at 3 months after the COVID-19 diagnosis. The mortality rate in the first 3 months after presentation with COVID-19 is high, especially among PD patients who were hospitalised. PD patients with COVID-19 had a higher mortality risk than HD patients. The majority of surviving patients recovered both functionally and mentally from COVID-19 within 3 months.

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

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. 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). 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. 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.

Serum myostatin levels are associated with physical function and hospitalization in peritoneal dialysis patients.

Myostatin functions as a negative regulator of skeletal muscle growth. The association of myostatin with muscle parameters in dialysis patients is inconsistent, and there are no studies associating myostatin with physical function and outcomes in peritoneal dialysis (PD) patients. Therefore, we assessed the association of serum myostatin with lean mass, physical function, and hospitalization in a prospective cohort of PD patients. Lean mass, physical function, and serum myostatin were assessed at baseline. Patients were followed up for at least 24 months and hospitalization was recorded. Serum myostatin levels were positively correlated with handgrip strength and Appendicular Lean Mass Index among male patients. Binary logistic regression models were performed including myostatin levels and physical function parameters as independent variables. Serum myostatin, handgrip strength, gait speed, and Short Physical Performance Battery were associated with hospitalization. Lower serum myostatin and physical function were associated with hospitalization in PD patients.

Influence of peritoneal dialysis catheter type on dislocations and laxative use: a retrospective observational study

BackgroundThere is currently no consensus regarding the optimal type of peritoneal dialysis (PD) catheter. Although few studies showed that weighted catheters result in lower complication rates and superior long-term outcomes than non-weighted catheters, there are no studies on the use of laxatives linked to catheter malfunction, a patient-related outcome potentially affecting the quality of life. Thus, we compared the burden of acute and chronic laxative use in a cohort of PD patients having either weighted or non-weighted catheters.MethodsWe performed a single-center, retrospective, observational study in two renal units, comparing acute and chronic laxative therapy related to catheter drainage failure in a cohort of 74 PD patient,s divided by peritoneal dialysis catheter type. In addition, we evaluated the number of patients who experienced minor and major dislocations, catheter-related infection rate, hospitalization for catheter malfunctioning, episodes of catheter repositioning, and dropout from PD.ResultsLaxative use was significantly more common among patients in the non-weighted catheter group (acute: 30.3% vs. 9.8%, p = 0.03; chronic: 36.4% vs. 12.2%; p≤0.02). Furthermore, weighted catheters were superior to non-weighted catheters for all the secondary outcomes (dislocations: 12.2% vs. 45.5%; p = 0.001).ConclusionsWeighted self-locating catheters have lower drainage failure, thus reducing the need and burden of acute and chronic laxative use among PD patients.Graphical abstract

MO699: Investigating Longer Term Antibody Response Following Covid-19 Vaccination in Patients Receiving Peritoneal Dialysis—a Single-Center Observational Study

BACKGROUND AND AIMSIndividuals with end-stage kidney disease (ESKD) have a greater susceptibility towards coronavirus disease 2019 (COVID-19) infection compared to those without chronic kidney disease or ESKD, and these patients are more vulnerable to poor clinical outcomes. The introduction of COVID-19 vaccination programs displayed efficacy to improving clinical outcomes. A study based in the UK reported excellent humoral responses to the Pfizer BNT162b2 vaccine, but suboptimal responses to the Oxford AstraZeneca ChAdOx1-nCoV-19(AZD1222) vaccine amongst hemodialysis patients. High rate of humoral responses to two doses of the COVID-19 vaccination has been reported within small cohorts of peritoneal dialysis (PD) patients 3 to 8 weeks post vaccination, whilst one study confirmed maintenance of significant humoral responses 6 months post vaccination with the Pfizer BNT162b2 vaccine. Our study aimed at evaluating longer-term antibody responses—6 months after a two-dose regimen of the Pfizer BNT162b2 and Oxford AstraZeneca ChAdOx1-nCoV-19 (AZD1222) vaccines in patients receiving PD.METHODThis is a single-center observational study conducted for PD patients who were offered both doses of the COVID-19 vaccine [either Pfizer BNT162b2 or Oxford AstraZeneca ChAdOx1-nCoV-19(AZD1222)] since universal introduction of the vaccination program in our local area in December 2020. COVID-19 antibody testing was performed using the Siemens’ immunoassay targeting the spike protein S1 RBD (an index ≥ 1.0 was deemed as a positive result) between October and November 2021. Demographic and baseline clinical data were collected for each patient, and analysis focused on comparing the characteristics between PD patients with positive and negative COVID-19 antibody statuses. Statistical analysis was performed using SPSS version 24.RESULTSEighty-six patients were included in this study. The median age was 62 years (47–71) with a predominance of males (61.6%) and Caucasian ethnicity (75.6%). The majority of patients have hypertension (84.8%) with 38% having a history of cardiovascular disease and 34% being diabetic. Ten patients (11.6%) previously received a kidney transplant with 7 patients (8.2%) currently on immunosuppressive treatment, and 15 patients (17.4%) previously receiving such treatments. A total of 81 patients received both doses of the COVID-19 vaccine, of which 57 (70.4%) received Pfizer BNT162b2, 16 (19.7%) received Oxford AstraZeneca ChAdOx1-nCoV-19 (AZD1222) and the type of vaccine was unknown in 8 patients (9.9%). A total of 72 patients were COVID-19 antibody tested between October and November 2021 in which 68 (94.4%) had a positive antibody and 4 (5.6%) had a negative antibody test. The median time between first dose of the COVID-19 vaccination and antibody testing was 9 (8.6–9.5) months and the median time between second dose of the COVID-19 vaccination and antibody testing was 6.3 (5.8–6.7) months. Comparing the demographic and clinical characteristics between patients with positive and negative antibodies, a higher proportion of patients with history of receiving immunosuppression (currently or previously; P = 0.004) had a negative antibody status despite receiving two doses of COVID-19 vaccination. There were no further significant differences observed. Full study results are presented in Tables 1 and 2.CONCLUSIONIn our cohort of PD patients, detectable humoral response to COVID-19 vaccination was sustained 6 months following vaccination irrespective of the type of vaccination received. A higher proportion of patients with a history of receiving immunosuppression (current or past) had a poor antibody response following COVID-19 vaccinations, highlighting the importance of considering focused COVID-19 vaccination strategies in the context of immunosuppression.

MO706: The Peritoneal Equilibration Test at the Start of Peritoneal Dialysis and Patient Outcome. Analysis in the Presence of Competing Events

Abstract BACKGROUND AND AIMS The success of peritoneal dialysis (PD) depends on the integrity of the peritoneal membrane. The most common peritoneal functional alteration is an impaired ultrafiltration caused by fast peritoneal solute transfer rate. This situation can be present at start of PD and compromise the durability of the membrane through the stay on PD. If the patient leaves PD for another reason, as in the case of a kidney transplant, it affects the probability of a membrane dysfunction appearance. It is known as a competitive event. The aim of this study was to determine whether baseline peritoneal transport status was a risk factor of mortality and technique failure in a cohort of Spanish PD patients using a statistical competing risk model. METHOD The multicenter retrospective cohort study included adult patients of the Levante Registry PD Work Group in Spain who started PD between February 1993 and June 2020. All patients needed to have a peritoneal equilibration test (PET) performed within the first 6 months after PD start. Patients were followed until technique failure, transplantation, renal function recovery, death, or until September 2020. Peritoneal transport status was considered both as a continuous (D/PCr4h) and as a categorical variable, according to the four groupings of D/PCr values defined by Twardoski. We analysed the effect of peritoneal transport over mortality, peritonitis and technique failure by a competing risk model. Kidney transplantation and renal function recovery were considered competing events. RESULTS A total of 4848 patients were enrolled. Baseline PET measurements were available in 2.307 (47.6%). The median follow-up time was 22.2 months (IQR 11.5–40.5). The main characteristics according to the peritoneal transport status are summarized in Table 1. When peritoneal membrane transport was analysed as a continuous variable, D/PCr was an independent risk factor of technique failure. The hazard ratio subdistribution for technique failure was 1.08 [(1.01; 1.16), P-value = 0.018] for every 0.1 increase in D/P Cr ratio. This effect disappeared when the use of icodextrin was included in the model. Baseline peritoneal transport was not associated with a higher mortality or peritonitis risk. CONCLUSION Basal peritoneal transport rate is an independent risk factor for death-censored technique failure in the Levante DP incident population. The use of icodextrin in these patients seems to mitigate this negative effect and may improve the outcomes in PD in patients with initial fast transport. Conventional methods for survival analysis ignoring the competing events may be inappropriate this cohort of patients.

Pleiotropic effects of atorvastatin in peritoneal dialysis patients: A retrospective-prospective observational cohort study

Abstract. Recent studies demonstrate a large number of non-lipid modifiable effects of statins in various diseases. However, although atherogenic dyslipidemia is a common feature in peritoneal dialysis (PD) patients, statins use is supported by limited data and there is a general lack of research on their pleiotropic effects in this patients’ cohort. The present study aimed to evaluate the possible pleiotropic effects of atorvastatin in PD patients.
 Methods. A total of 114 PD patients with an average age of 55 (48-65) years and a dialysis vintage of 31 (14-50) months were included in this combined retrospective and prospective multicentre cohort study. PD patients (n = 54) who had started receiving atorvastatin before or after dialysis initiation and been treated with atorvastatin no less than 12 months were included in the Atorvastatin Group. PD patients (n = 60) who have never taken statins consisted of Atorvastatin-free Group.
 In addition to routine clinical and PD adequacy tests, concentrations of interleukins -6, -10, tumor necrosis factor-alpha, and monocyte chemoattractant protein-1 in PD effluent (PDE) were evaluated in all study participants at the start of the follow-up period. The primary outcomes were the 3-year PD technique survival and the all-cause mortality of PD patients during the follow-up period.
 Results. Atorvastatin users had lower serum phosphate and parathyroid hormone concentrations, higher weekly creatinine clearance, peritoneal weekly Kt/V urea, and, accordingly, total weekly Kt/V compared to the Atorvastatin-free Group. PDE cytokines assessment demonstrated significantly lower concentrations of all studied cytokines in the Atorvastatin Group compared with the Atorvastatin-free Group. In the Cox regression models, atorvastatin use was significantly associated with better PD technique survival (HR = 0.28 (95% CI 0.15; 0.54), p = 0.003) and mortality reduction in the PD patients regardless of their age, diabetes, anuric status, albumin and C-reactive protein levels, and history of PD peritonitis (HR = 0.24 (95% CI 0.15; 0.44), p < 0.0001).
 Conclusions. Atorvastatin treatment was associated with the normalization of phosphate-calcium metabolism, low intraperitoneal inflammation and incidence of PD-associated peritonitis, and better dialysis adequacy in our cohort of PD patients. These pleiotropic effects of atorvastatin may be one of the reasons for the lower all‐cause mortality in PD patients. Further studies are needed to determine the necessity of statins prescribing in PD patients.

Prevalence and correlates of low plasma selenium concentrations in peritoneal dialysis patients

ObjectiveSelenium is a key component in multiple enzyme systems, and dialysis patients with lower levels have been reported to have increased mortality. Low selenium levels were commonly reported in historic hemodialysis patients, but not in recent studies. There have been very few studies in peritoneal dialysis (PD) patients, and with the increasing age and frailty of our PD population we wished to review factors associated with lower selenium in PD patients. Design & methodsWe retrospectively reviewed plasma selenium, normal laboratory >0.8 umol/L, measurements from a cohort of PD patients, attending for routine peritoneal membrane assessments, along with measurement of dialysis adequacy (Kt/Vurea), and normalized nitrogen appearance rate (nPNA) and bioimpedance measured extracellular water (ECW)/total body water (TBW), and skeletal muscle mass indexed for height (SMMI). ResultsThe median plasma selenium was 0.84 (IQR-0.72–1.01) umol/L in 406 PD patients, 61.1 % male, mean age 59.0 ± 15.5 years, 44.9 % diabetic with 15.8 % designated as clinically frail (CFS). 41.4 % had selenium deficiency (<0.8 umol/L), and was more common with increasing CFS (χ2−6.8, p < 0.009), comorbidity grade(χ2−26.74, p < 0.001).Plasma selenium correlated with serum total protein (TP) (r = 0.352), albumin (r = 0.358), nPNA (r = 0.263), and negatively with ECW/TBW (r= -0.321) all p < 0.001, and positively with SMMI (rho = 0.109, p = 0.03). On multivariable analysis selenium was independently associated with TP (β 0.799 ± 0.15,95 % confidence limits (95CL) (0.505−1.093), p=<0.001), and negatively with C reactive protein (CRP) (β -0.02 ± 0.01, (95CL -0.047 to -0.005) p = 0.01), and ECW/TBW (β -1.499 ± 0.42 (95CL -2.33 to -0.666) p=<0.001). ConclusionsCompared to recent studies in hemodialysis patients, we report a 41 % prevalence for low selenium levels. Plasma selenium was positively associated with total serum protein, and negatively with CRP and ECW/TBW. Thus, lower selenium concentrations were linked to reduced dietary protein intake, and increasing frailty, inflammation and ECW/TBW ratios.

The Association of Circulating CD14++CD16+ Monocytes, Natural Killer Cells and Regulatory T Cells Subpopulations With Phenotypes of Cardiovascular Disease in a Cohort of Peritoneal Dialysis Patients

The altered expression of immune cells including monocyte subsets, natural killer (NK) cells and CD4+CD25+ regulatory T cells (Tregs) in end-stage kidney disease, affect the modulation of inflammation and immunity with significant clinical implications. The aim of this study was to investigate the profile of specific immune cells subpopulations and their correlations with phenotypes of established cardiovascular disease (CVD), including coronary artery disease (CAD) and heart failure (HF) in peritoneal dialysis (PD) patients.Materials and Methods: 29 stable PD patients and 13 healthy volunteers were enrolled. Demographic, laboratory, bioimpedance measurements, lung ultrasound and echocardiography data were collected. The peripheral blood immune cell subsets analysis was performed using flow cytometry.Results: PD patients compared to normal controls had lower total lymphocytes (22.3 ± 6.28 vs. 31.3 ± 5.54%, p = <0.001) and B-lymphocytes (6.39 ± 3.75 vs. 9.72 ± 3.63%, p = 0.01) as well as higher CD14++CD16+ monocytes numbers (9.28 ± 6.36 vs. 4.75 ± 2.75%, p = 0.0002). PD patients with prevalent CAD had NK cells levels elevated above median values (85.7 vs. 40.9%, p = 0.04) and lower B cells counts (3.85 ± 2.46 vs. 7.2 ± 3.77%, p = 0.03). Patients with increased NK cells (>15.4%) had 3.8 times higher risk of CAD comparing with patients with lower NK cell levels (95% CI, 1.86 – 77.87; p = 0.034). B cells were inversely associated with the presence of CAD (increase of B-lymphocyte by 1% was associated with 30% less risk for presence of CAD (95% CI, −0.71 – 0.01; p = 0.05). Overhydrated patients had lower lymphocytes counts (18.3 ± 4.29% vs. 24.7 ± 6.18%, p = 0.006) and increased NK cells [20.5% (14.3, 23.6) vs. 13.21% (6.23, 19.2), p = 0.04)]. In multiple logistic regression analysis the CRP (OR 1.43; 95% CI, 1.00 – 2.05; p = 0.04)] and lymphocytes counts (OR 0.79; 95% CI, 0.63–0.99; p = 0.04)] were associated with the presence of lung comets. Patients with higher NK cells (>15.4%, n = 15) were more likely to be rapid transporters (D/P creatinine 0.76 ± 0.1 vs. 0.69 ± 0.08, p = 0.04). Patients displaying higher Tregs (>1.79%) were older (70.8 ± 10.7 years vs. 57.7 ± 14.7years, p = 0.011) and had higher nPCR (0.83 ± 0.14 vs. 0.91 ± 0.17, p = 0.09).Conclusion: Future research is required to evaluate the role of immune cells subsets as potential tools to identify patients at the highest risk for complications and guide interventions.

616BMI and SBP impact on survival of dialytic patients: multivariate joint model approach

Abstract Background Studies on impact of routine clinical parameters on mortality of patients on peritoneal dialysis (PD), especially among elderly, are inconsistent. Although association between body mass index (BMI) and systolic blood pressure (SBP) is well known, their joint role on PD patient evolution is not clear. We aimed to model the joint impact of BMI and SBP trajectories on a cohort of incident elderly PD patients. Methods Prospective multicenter cohort study with 674 patients. Repeated measurements were modeled by random effects multivariate linear model. For the time-to-event outcome, used Cox proportional hazards model with log-Gaussian frailty. Stochastic dependence is captured by allowing random effects of the linear model to be correlated with the frailty term of the survival model, allowing for different clinical interpretations. All sub-models were adjusted for age in years. Results Isolated current values effects of increased BMI and BPS showed both as protective factors (1% and 2% risk reduction, respectively, for each unitary increase). When jointly modeled BMI changed its effect to 5% risk reduction while BPS remained the same, showing great impacts on survival depending on the combination of trajectories. Conclusions Clinical parameters association and its impact on survival is complex, and estimation of isolated effects may provide biased survival curves leading to unrealistic prognosis. A multivariate joint modeling can be seen as a valuable tool for clinical protocols on patient evolution. Key message Modern clinical epidemiology must foster use of modern statistics

MO695THE ASSOCIATION OF CIRCULATING CD14++CD16+ MONOCYTES, NATURAL KILLER CELLS AND REGULATORY T CELLS SUBPOPULATIONS WITH CARDIOVASCULAR DISEASE IN A COHORT OF PERITONEAL DIALYSIS PATIENTS

Abstract Background and Aims Advanced chronic kidney disease (CKD) is characterized by elevated expression of the proinflammatory and pro-atherogenic CD14++CD16+ monocytes subset. The role of lymphocyte subpopulations including natural killer (NK) cells and CD4+CD25+ regulatory T cells (Tregs) in the modulation of inflammation and immunity and subsequent cardiovascular implications have received increasing attention. The role of immune cell subpopulations remains to be determined in peritoneal dialysis (PD) patients. The aim of this pilot study was to investigate potential correlations between blood levels of CD14++CD16+ monocytes, NK cells and Tregs with phenotypes of established cardiovascular disease (CVD), including coronary artery disease (CAD) and heart failure (HF) in a cohort of PD patients. Method 29 stable PD patients (mean age 66.96 years ±14.5, 62% males) were enrolled. Exclusion criteria were a history of malignancy, autoimmune disease, active or chronic infections and a recent (&amp;lt; 3 months) cardiovascular event. Demographic, laboratory and bioimpedance measurements data (overhydration, extracellular and total body water and their ratios) were collected. The analysis of peripheral blood immune cell subsets was performed using flow cytometry (FC). Additionally, in 7 PD patients the distribution of the immune cells was evaluated by FC at two time points: T0 (before initiation of PD - CKD stage G5) and T1 (after PD start). Results The median dialysis vintage was 34.5 (range 3.2-141) months. Overall, PD patients had 527 ± 199 monocytes and 1731 ± 489 lymphocytes while mean percentage of CD14++CD16+ monocytes was 9.3 ±6.36% (normal range 2-8%), NK cells 16.6±10.3% (normal range 5-15%) and Tregs 2.1±1.76% (normal range 1-3%). There was no correlation of either of these cell subpopulations with age, PD vintage, inflammation markers (CRP, fibrinogen, albumin, hsTroponin-I), overhydration markers or comorbidities. Only increased NK cells were associated with the presence of HF in PD (24.87 vs 14.92%, p 0.047). In multiple regression analysis, NK cells levels were strongly associated with the presence of edema (beta coef=13.7, p&amp;lt;0.001) and CAD (beta coef=7.1, p=0.046). At T0 mean percentage of CD14++CD16+ monocytes, NK cells and Tregs were 9.7 ±4.5%, 17.1 ±3.84% and 2.38± 1.26% respectively whereas at T1 mean percentage of CD14++CD16+ monocytes was 13.3% ±8.4, NK cells 19.8±6.47% and Tregs 1.5±0.6%. Paired t-test of cell subpopulations (T0 vs T1) showed that only the Tregs were significantly decreased (p =0.018), while the other subpopulations did not differ and remained increased. Conclusion Our study is the first to evaluate the potential association between specific immune cell subsets and cardiovascular disease in long-term PD patients. Increased NK cells levels directly correlate both with the presence of HF and CAD in PD patients. Longitudinal results suggest that CD14++CD16+ and NK cells remain increased after PD start, while Tregs decrease further. The state of pro-inflammation and immune deregulation appear to persist after initiating PD. Future research is required to evaluate the role of immune cells subsets as potential tools to identify patients who are at the highest risk for complications and to guide interventions that may improve clinical outcomes.

MO700EPIDEMIOLOGICAL ADMISSIONS IN PERITONEAL DIALYSIS IN A SINGLE DIALYSIS CENTER

Abstract Background and Aims The knowledge of the impact of peritoneal dialysis (PD) program in terms of hospitalization rate can provide solid guidance for nephrologists for management purpose. In a historical cohort of adult PD patients, we examined the hospitalization rates and causes of hospital admissions. Method One hundred ninety-one consecutive PD patients between January 1st 2000 to December 31st 2018 were enrolled. The maximum follow up was 194 months. Their mean age was 65±15 years, 110 were males, 56 had co-morbidities and 67 were diabetics. The median PD vintage was 35 months (interquartile range 20-63 months). Results During the follow-up, 163 out of 191 patients (85%) underwent hospital admission for a total of 356 hospitalizations [57 hospitalizations per 100-person-years]. The most frequent cause of admission was infection (20 hospitalizations per 100-person-years) mainly due to peritonitis (12 hospitalizations per 100-person-years) followed by cardiovascular diseases (17 hospitalizations per 100-person-years). Hospitalizations due to miscellaneous causes were 21 per 100-person-years. In the whole group, high NYHA score [Incidence Rate Ratio (IRR): 1.52, 95%CI 1.21-1.89, P&amp;lt;0.001], residual diuresis &amp;lt;500 ml/die (IRR: 1.43, 95%CI 1.13-1.82, P=0.002), malnutrition (IRR: 1.47, 95%CI 1.08-1.99, P=0.01) and older age (&amp;gt;65 years) (IRR 1.26, 95%CI 1.02-1.56, P=0.03) and were associated to all-cause hospitalizations. In an analysis by hospitalization type, the factors related to admission for infection diseases was malnutrition (IRR: 1.91, 95%CI 1.16-3.03, P=0.005) and high NYHA score (IRR: 1.52, 95%CI 1.03-2.22, P=0.02). As expected, hospitalizations due to cardiovascular causes were strongly related to older age (&amp;gt;65 years) (IRR 2.02, 95%CI 1.35-3.03, P&amp;lt;0.001), diabetes (IRR 2.13, 95%CI 1.43-3.18, P&amp;lt;0.001), high NYHA score (IR 2.14, 95%CI 1.43-3.21, P=0.001], residual diuresis &amp;lt;500 ml/die (IRR: 1.65, 95%CI 1.06-2.55, P=0.02) and previous cardiovascular events (IRR: 1.50, 95%CI 0.98-2.25, P=0.05). Conclusion Analyzing the causes and the rate of hospitalization in PD patients allows more accurate management of these high risk category of patients and contributes to a more efficient organization of a renal department.

MO696INCREMENTAL PERITONEAL DIALYSIS: BENEFICIAL EFFECTS

Abstract Background and Aims Incremental peritoneal dialysis (Incr_Dial) is a renal replacement therapy strategy based on lower dose prescription rather than the standard “full dose” (Full_Dial). Individualized clearance goals were achieved combining residual renal function (RRF) and peritoneal clearance. Maintaining RRF is a crucial issue to peritoneal dialysis (PD) patients and the best PD strategy to preserve it is subject to debate. The aim of this study is to compare Incr_Dial and Full_Dial in terms of RRF preservation and other clinical outcomes. Method This was a single-center, retrospective descriptive study. We included a cohort of incident and prevalent adult PD patients in the PD Unit between January – December of 2020. Patients without a follow-up &amp;lt; six months and who started PD at another center were excluded. Patients were assigned according to their first PD protocol in two groups – Group A: Incr_Dial protocol (continuous ambulatory PD: less than four dwells daily, less than 2 L dwell volumes, less than seven days a week treatment, or some combination of these; automated PD: without a long dwell, less than 10 L daily delivered by cycler and day dwells, treatment for less than 7 days a week or some combination of these); Group B: Full_Dial protocol. Statistical analysis was performed using SPSS 20.0. Statistical significance level p &amp;lt;0.05. Results Among 84 PD patients, 68% underwent incremental PD (Group A) and 31% underwent conventional full-dose PD (Group B). The mean age was 55.9±15.4 years, 60.7% were male and 32.5% diabetic. There were no statistically significant differences between the two groups regarding: demographic characteristics, comorbidities (diabetes, hypertension, cardiac insufficiency or ischemic heart disease) and drugs (angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and/or loop diuretics). The median Incr_Dial duration to achieve PD full dose was 10.2 months (IQ 5.1-17). At the beginning of PD, there was no statistically significant difference in diuresis between both groups (A: 1.79L vs B: 1.2L, p=0.07), however after 6 months of PD there was a superior urinary output in Group A (A: 1.67L vs B: 1.1L, p=0.037). Group A (Incr_Dial) was also associated with a superior renal clearance of creatinine at the beginning (A: 81 L/sem/1.73m2 vs B: 56.8L/sem/1.73m2, p=0.021) and after 12 months (A: 70.7L/sem/1.73m2 vs B: 26.3 L/sem/1.73m2, p&amp;lt;0.01); and superior Kt/V renal/week at the beginning (A: 1.48 vs B: 1.02, p=0.02) and after 12 months (A: 1.28 vs B: 0.49, p&amp;lt;0.001). There are no differences between mortality (A: 1.9% vs B: 12%, p=0.094), peritonitis-free time (A: 158 days vs B: 236 days, p=0.133) and the numbers of peritonitis per year (A: 0.32 vs B: 0.5, p=0.940). However, the rate of hospital admissions per year was lower in Group A (A: 0.22 vs B: 0.70, p=0.001). Conclusion Incremental PD is a safe strategy of renal replacement therapy to start PD. In our PD population, it showed similar patient survival rates and a significantly less hospital admissions. Incremental PD was also beneficial for preserving RRF when compared to full-dose PD.

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?

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.