Although hypomagnesemia is theoretically induced by the peritoneal dialysis (PD) environment, its real-world risk and clinical correlates remain unclear, and its association with atrial fibrillation (AF) has not been evaluated. We conducted a cross-sectional study using nationwide data from the 2019 annual survey of the Japanese Society for Dialysis Therapy. Adults (≥ 20years) undergoing hemodialysis (HD) or PD were included. Serum magnesium (sMg) was categorized into five groups (≤ 1.5, > 1.5- ≤ 2.0, > 2.0- ≤ 2.5, > 2.5- ≤ 3.0, and > 3.0mg/dL). The prevalence of hypomagnesemia (≤ 1.5mg/dL) was compared among PD-only, hybrid, and HD patients. Among PD-only and hybrid patients, the association between sMg and AF was examined using logistic regression. Factors associated with sMg levels were further analyzed using a general linear model. A total of 2,347 PD, 806 hybrid, and 177,779 HD patients were analyzed. The prevalence of hypomagnesemia was 6.2% in PD-only, 3.6% in hybrid, and 0.5% in HD patients. Hypomagnesemia was significantly associated with AF (adjusted OR 2.96, 95% CI 1.64-5.33). Lower sMg levels were associated with higher renal Kt/V, higher total daily dialysate volume, use of icodextrin, and higher peritoneal equilibration test dialysate-to-plasma ratio, whereas higher sMg levels were associated with greater ultrafiltration volume, use of automated PD, and hybrid dialysis. Hypomagnesemia is common in PD and is associated with an increased prevalence of AF. Further studies are warranted to identify the optimal sMg range for AF prevention and to develop PD prescription strategies for maintaining appropriate sMg levels.

Abstract Background and Aims Volume overload is associated with increased mortality in dialysis patients, making it essential to maintain euvolemia. Currently, several methods have been developed to help manage the volume including clinical and paraclinical parameters. The primary objective of this study is to describe the relationship between parameters associated with hypervolemia in patients enrolled in a peritoneal dialysis (PD) program. The secondary objective is to characterize these patients using point-of-care ultrasound (PoCUS) and composite congestion score (CCS) as methods to complement the assessment of congestion phenotypes. Method A cross-sectional observational comparative study was conducted involving PD patients. Patients were divided into two groups based on the results of congestion assessed by bioelectrical impedance: non-congestive (Group 1, n = 15) and congestive by bioelectrical impedance (Group 2, n = 7). Additionally, an ultrasound examination was performed twice (Lung US, inferior vena cava diameter, portal vein pulsatility) during the visit for the peritoneal equilibration test (PET) and afterward. Results are presented as means ± standard deviation for variables exhibiting a normal distribution and as medians for variables displaying a non-normal distribution. Normality was assessed using the Shapiro-Wilk test. Group comparisons were conducted using the Mann-Whitney and Kruskal-Wallis tests for variables with a non-normal distribution. Relationships between parameters were examined using Spearman's correlation test. Significance was established at P < 0.05. The statistical software used was SPSS version 30. Results We found that patients in Group 2 had hypertension, heart failure, and valvulopathies: mitral and aortic regurgitation. Additionally, statistically significant differences were identified in intraperitoneal pressure and interventricular septum thickness, which were greater in this group. However, Group 1 showed higher residual diuresis (Table 1). A relationship was identified between residual diuresis and the CHARLSON score (P = 0.035) as well as pulmonary artery systolic pressure (P = 0.023). Additionally, BNP values were correlated with Ca-125 (P = 0.05) and the vena cava diameter during PET and post-PET (P = 0.005), but no significant correlations were found with the rest of the variables analyzed. In the group analysis, the Composite Congestion Score showed a significant correlation with age (P = 0.043) and Ca-125 (P = 0.042), as well as hypervolemia determined by bioimpedance and residual diuresis (P = 0.033). Conclusion In the Group 2, the CCS did not show a significant correlation with any of the variables analyzed. Additionally, the US assessment before and after PET did not reveal significant variations. Ca-125 and NT-proBNP levels were higher in Group 2, but without statistical significance. Given the complexity of maintaining euvolemia in dialysis patients, analyzing the characteristics of congestive patients is key to adjusting depletive treatment.

Abstract Background and Aims The decline in peritoneal salt and water clearance is a major cause of dropout in peritoneal dialysis (PD). This study evaluated changes in fluid and solute transport in incident PD patients over first four years using the peritoneal equilibration test (PET). Method A retrospective single-center study was conducted on incident PD patients who underwent 4-hour 3.86% glucose PET with ultrafiltration (UF) measured at 1 hour, assessed at ≥3 months post-initiation and annually for four years. Transport parameters included D/P creatinine (D/P), UF, fluid total removal (FTR), sodium sieving (ΔDNa), free water transport (FWT), small-pore ultrafiltration (SPUF), and sodium removal (RNa). Serum CA-125 was also measured. Statistical analysis was performed using SPSS (Version 29). Results Fifty-nine patients were included: 32.2% female (n = 19), 33.9% diabetic (n = 20), and 74.6% (n = 44) on automated PD. Mean age was 56.7 ± 11.5 years. Diabetic kidney disease accounted for 23.7% (n = 14) of renal disease etiologies. Initial PET showed a weekly Kt/V of 2.53 ± 0.75, urine volume of 1.84 ± 0.85 L/24 h. High-average transporters comprised 55.9% (n = 33). Mean UF at 4 h was 0.87 ± 0.30 L, UF at 1 h 0.58 ± 0.23 L, SPUF 0.32 ± 0.21 L, FWT 0.27 ± 0.08 L, % FWT 48.7 ± 13.3%, ΔDNa 10.8 ± 3.9 mmol/L, RNa 50.47 ± 28.91 mmol/L, D/P 0.06 ± 0.12, TFR 2.31 ± 0.805 and CA-125 59.3 ± 125.6 U/mL. At 1 year (n = 40), FWT (0.25 ± 0.06 L, P = 0.046) and TFR (2.00 ± 0.68 L, P = 0.006) significantly decreased. Non-significant increases were observed in % FWT (46.60 ± 15.06%), SPUF (0.33 ± 0.18 L) and D/P (0.69 ± 0.14) while reductions were noted in ΔDNa (10.62 ± 3.35 mmol/L), RNa (47.92 ± 20.68 mmol/L), diuresis (1.59 ± 0.72 L/24 h) and CA-125 (39.50 ± 25.70 U/mL). In the second PET (n = 23), ΔDNa (10.00 ± 3.00 mmol/L, P = 0.003), FWT (0.22 ± 0.06 L) and diuresis (1.39 ± 0.79 L, P = 0.001) significantly declined. Non-significant decreases were seen in SPUF (0.31 ± 0.27 L), % FWT (43.14 ± 16.81), RNa (42.25 ± 41.40 mmol/L), D/P (0.68 ± 0.13 mmol/L) and TFR (1.86 ± 1.32 L) while CA-125 increased (42.00 ± 20.50 U/mL). At 3 years (n = 11), significant declines were noted in FWT (0.19 ± 0.07 L, P = 0.035), ΔDNa (8.00 ± 6.00 mmol/L, P = 0.032), and diuresis (1.25 ± 0.74 L, P = 0.046). SPUF (0.32 ± 0.17 L), CA-125 (48.47 ± 15.66 U/mL), and D/P creatinine increased non-significantly. At 4 years (n = 10), ΔDNa (9.00 ± 2.50 mmol/L, P = 0.050) and diuresis (1.238 ± 0.828 L, P = 0.047) significantly decreased. Non-significant increases were observed in SPUF (0.30 ± 0.12 L), RNa (41.42 ± 17.62 mmol/L), and CA125 (41.14 ± 18.42 U/mL). Non-significant decreases were noted in TBW (0.23 ± 0.10 L), %TBW (40.76 ± 30.37%) and Kt/V (2.07 ± 0.45). The Friedman test revealed a statistically significant variation in sodium sieving (ΔDNa) across the 5-year follow-up (X2(4) = 9.472; P = 0.050). Statistically significant correlations were identified between ΔDNa variation and UF at 1h (r = 0.719, P = 0.019). Variation in FWT showed significant correlations with UF at 1h (r = 0.773, P = 0.009), sodium removal (r = 0.937, P < 0.001), D/P creatinine (r = −0.691, P = 0.027), and Kt/V (r = 0.719, P = 0.019). Additionally, sodium removal was significantly correlated with Kt/V variation (r = 0.726, P = 0.017). Conclusion This study showed a significant decline in diuresis and ultrafiltration over four years, reflecting reduced residual renal function and sodium sieving. These changes may be explained by progressive fibrosis and neovascularization of the peritoneal membrane, favoring small-solute transport over free water transport. This emphasizes the importance of individualized dialysis strategies and early monitoring to improve patient outcomes.

Abstract Background and Aims Peritoneal protein loss (PPL) through peritoneal effluent is a well-established complication of peritoneal dialysis (PD) and has been linked with malnutrition and mortality. However, the perspective is changing. The association of PPL with malnutrition and sarcopenia has been refuted in recent studies. Moreover, recently, fluid overload and venous congestion have been associated with PPL uncovering the importance of hydrostatic convection in protein transport. The aim of this study was to explore the relation of PPL with fluid overload, sarcopenia and nutritional markers in prevalent PD patients. Method We performed a single-center cross-sectional study that included all PD patients of our unit submitted to a modified peritoneal equilibration test (PET) during the year 2024. Demographic and clinical data were collected from clinical records. Biochemical data, evaluation of sarcopenia and bioelectrical impedance assessment (BIA) were evaluated at the same time as PET. PPL was measured in a 24h dialysate effluent collection and the PET’s dialysate effluent (4 h). NTproBNP, CA 125 and extracellular water excess in BIA were used as fluid overload markers, and albumin, total proteins, handgrip strength, ultrasound evaluation of rectus femoris and BIA parameters as nutritional and sarcopenia markers. Statistical analyses were done in SPSS. Univariable analysis were performed with linear regression model and a p value ≤ 0.05 was considered significant. Results Our study included 61 patients, 39 (64%) male, with a mean age of 59 ± 13 years, and 20 (33%) were diabetic. Cause of renal failure was diabetes in 15 patients (24.6%), ADPKD in 7 (11.5%), hypertension in 6 (9.8%), IgA nephropathy in 5 (8.2%) and cardiorenal syndrome in 4 (6.5%), other causes were less frequent. Most patients (73%) were on continuous ambulatory peritoneal dialysis (CAPD). Median PPL was 0.081g/dL (0.055–0.099) in the 24h dialysate and 0.046 g/dL (0.039–0.063) in the 4 h dialysate. Regarding fluid overload, median NTproBNP was 1260 pg/mL (517–3702), median CA125 was 13 U/mL (9–23) and mean extracellular water excess was 1.5 L ± 1.6. Average handgrip strength was 28 and 26kg, right and left arm, respectively, with a mean rectus femoris muscle thickness of 13.7 mm ± 4.4. Remaining data, including PET parameters, are detailed in Table 1. Univariable analysis showed a positive association between 4h PPL and NTproBNP (P = 0.001), extracellular water excess (P = 0.018) and lean tissue mass (LTM) (P = 0.006). A negative association was found between 4h PPL and fat mass in BIA (P = 0.015). Albumin, total proteins, handgrip strength, muscle thickness and other BIA parameters did not correlate with PPL. Conclusion Our study coincides with recent data reinforcing an absence of causality and relationship between PPL sarcopenia and malnutrition markers. A positive correlation between LTM and 4 h PPL might be justified by a higher metabolic rate and more significant protein turnover in patients with more lean tissue mass. The same rationale explains a negative association between fat mass and 4 h PPL, as these patients tend to have lower protein turnover. On the other hand, a fluid overload status appears to play a role in PPL as evidenced by a significant relationship between 4 h PPL and NTproBNP and extracellular water excess.

Abstract Background and Aims The peritoneal equilibration test (PET) is essential for understanding peritoneal membrane transport in peritoneal dialysis (PD) treatment. However, peritoneal membrane function can be influenced by numerous factors, including fluid status. The aim of this study was to investigate whether tissue hydration influences PET results, including D/P creatinine and D/D0 glucose. Method Standard PET was performed with 2.5% glucose and 2 L of dialysate for a 4-hour dwell. Whole body and calf bioimpedance (Hydra 4200, Xitron Technologies, San Diego, CA) were measured in a sitting position, both pre- and post-PD treatment. Whole body extracellular volume (wECV) was estimated using the Xitron program. Calf normalized resistivity (CNR = resistance *cross-sectional area / body mass index) was defined (Fig. 1) as a hydration marker to evaluate fluid status in dialysis patients in our previous study (Zhu et al. Physiol Meas, 32:887–902, 2011). The concentrations of creatinine and glucose in blood plasma (P) and dialysate (D) samples were measured using standard methods. P/D creatinine and D/D0 glucose ratios were calculated to assess the function of peritoneal membrane transport. Linear regression analysis was used to determine the relationship between CNR and transport parameters. One-way ANOVA was used to identify differences in the changes of wECV (∆wECV) and CNR (∆CNR) during PD among different transport groups of patients. Results Sixteen PD patients (age 56.3 ± 11.9 years; nine females; weight 78.2 ± 20.3 kg) were studied. The transport types of the patients were divided into Low-average (n = 5), High-average (n = 9), and High (n = 2) based on P/D. CNR significantly increased from pre- to post-PD treatment in all patients (14.6 ± 2.1 vs 16.2 ± 2.9, 10−1*Ω*m3/kg, P < 0.0001). The study demonstrated that D/D0 and D/P significantly associated with CNR in pre-PD (Fig. 2a, R2 = 0.33, P < 0.05; Fig. 2b R2 = 0.43, P < 0.01) and post PD (Fig. 2c, R2=0.39, P < 0.01; Fig. 2d, R2 = 0.43, P < 0.01) respectively. In addition, water removal (∆wECV) was significantly greater in the Low-average group than in the High-average and High transport groups (P < 0.05; Fig. 3A) using One-way ANOVA. Meanwhile, ∆CNR was significantly lower in the High transport group compared to the High-average and Low-average groups of patients by One-way ANOVA (P < 0.05; Fig. 3B). Conclusion This study demonstrates that CNR is associated with peritoneal transport functions. Although the relationship between body hydration and peritoneal transport characteristics is not fully understood, the hydration state of the surrounding tissues in the peritoneal cavity could influence water removal from the tissue to the peritoneal cavity due to hydrostatic pressure (Fig. 3). Currently, it is still unclear whether variations in tissue hydration are a consequence of membrane function or its driving factor. If it is the latter, tissue hydration should be considered when using the standard PET to evaluate peritoneal membrane function. Further studies in a larger number of patients are warranted to corroborate our findings.

Abstract Background and Aims Osteoporosis and osteopenia are prevalent in patients with chronic kidney disease (CKD). They may represent an interaction between pathophysiological phenomena related to age and mineral-bone disorders. These overarching entities are complex and not fully understood despite their association with clinically significant outcomes. Our study aimed to evaluate bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) in prevalent PD patients and identify associations with potentially relevant variables. Method We conducted a retrospective study in our PD unit. Demographical and clinical data, results from routine blood analysis (including intact parathyroid hormone [iPTH] and bone alkaline phosphatase [bAP]), modified peritoneal equilibration test (PET), DXA, bioelectrical impedance analysis (BIA), muscle strength and nutritional parameters were evaluated. We also examined the concentrations of proteins, calcium (Ca), phosphorus (P), and magnesium (Mg) in serum, peritoneal fluid (at 0, 2 and 4 hours, during PET), and urine (24 hours). Results A total of 59 patients were included, with a median time on PD of 46 months, of which 66.1% were male, with a mean age of 59 ± 13 years. Regarding the aetiology of CKD, 23.7% of the cases were attributed to diabetic kidney disease and 11.9% to autosomal dominant polycystic kidney disease. When it comes to comorbidities, 32.2% of the patients had diabetes, 13.6% had coronary artery disease (CAD), 8.5% had cerebrovascular disease (CVD), and 11.9% had peripheral artery disease (PAD). Most patients (73.8%) performed continuous ambulatory PD (CAPD). A prevalence of 39% of osteoporosis and 36.6% of osteopenia was identified using DXA. Regarding trabecular bone score (TBS), we found a fully or partially degraded microarchitecture in 22.5% and 27.5% of the patients, respectively. We found no differences in TBS and BMD categories according to the presence or absence of diabetes, CAD, CVD, or PAD. There were also no statistically significant differences in the Z-scores (femoral neck, total femoral, and lumbar) between patients on different Ca concentrations on the dialysate and those receiving Ca or vitamin D supplementation or calcimimetics. We found a negative correlation between femoral and lumbar Z-scores and the dialysate-to-plasma (D/P) ratio of creatinine in univariable analysis, confirmed by linear regression (p < 0.005) adjusted for sex and diabetes. This association was also confirmed when both variables were transformed into nominal categories. Moreover, both Z-scores and Mg levels in peritoneal fluid also had a negative association. However, no significant associations were identified with other parameters, namely serum Ca, P, Mg, iPTH and bAP. A negative association between calcium ingestion and femoral and lumbar Z-scores was also found. Regarding body composition, we observed a significant association between lower Z-scores and higher fat mass (both using DXA and BIA), but no association with muscle strength or lean tissue in any of the methods. Conclusion Our findings suggest that the prevalence of osteoporosis and osteopenia in PD patients is significant, and high-transporters seem to be more vulnerable to low BMD. The driving mechanism appears to be related to higher Mg losses in the peritoneal fluid. The reason for this is unclear, although it might be related to decreased activation of calcium-sensing receptors and subsequent bone turnover. Lower Ca ingestion was also associated with low BMD. Moreover, in our study adipose tissue seems to have a protective role regarding BMD disorders. On the other hand, associations with protein losses and lean tissue were not found in our study. Further investigation is undoubtedly necessary to clarify these findings.

Abstract Background and Aims Tradition markers of dialysis adequacy in peritoneal dialysis (PD) correlate poorly with both patient symptoms and outcomes, and residual kidney function remains the better determinant of each. Largely in response to these findings, guidelines now recommend focusing on patient-reported outcome measures (PROMs) where they have been shown to predict mortality, technique survival and hospitalisations. We aim to assess whether PROMs correlated with traditional markers of dialysis adequacy and predicted future patient outcomes. Method This was a retrospective study on adult PD patients who underwent a Palliative care Outcome Scale Symptom (POS-S)-renal questionnaire within 2-weeks of their routine Peritoneal Equilibrium Test (PET)-Adequest test. We assessed for the association between POS-S renal scores with adequacy measures (Kt/V and creatinine clearance or CCr) and whether POS-S renal scores predicted future outcomes (remaining on PD, transition to haemodialysis, kidney transplantation or death on PD). Results There were 107 patients with at least one paired PET-Adequest and POS-S questionnaire. There was no correlation between markers of dialysis adequacy (CCr and Kt/V) and symptom burden measured by POS-S renal questionnaire. Higher symptom burden predicted less favourable outcomes including technique failure, hospitalisations and death (P < 0.05). There was also an association between a higher symptom burden and a lower serum albumin level (P < 0.001). Conclusion There was no association between dialysis adequacy markers and PROMs, but PROMs were able to predict technique failure, hospitalisations and death compared to markers of dialysis adequacy. The measurement of PROMs may provide a beneficial addition to dialysis assessment in routine PD care.

Abstract Background and Aims Technique survival on peritoneal dialysis (PD) is limited by treatment-related infections, mechanical catheter problems, psychosocial challenges, and/or peritoneal membrane failure. Traditionally, the evaluation of the peritoneal membrane function involves the time- and resource-consuming peritoneal equilibrium test (PET). Our group recently suggested that a glucose-corrected ultrafiltration (gcUF), calculated from cycler machine-readouts, may serve as a valuable and cost-effective biomarker for real-time peritoneal membrane monitoring. The aim of this study therefore was to evaluate this biomarker alongside other real-world treatment response measures in context of dialysis prescription to predict adverse outcomes in a large single-center cohort of patients on automated PD (APD). Method For this retrospective study we collected and analyzed daily APD cycler treatment response measures (as direct machine readouts) and prescription data of adult patients on APD treated between 2000–2022 at the Medical University of Vienna. Prescription data (i.e., daily glucose load, prescribed dialysis fluid volume) and subsequent treatment response measures (i.e., gcUF, cycler ultrafiltration) was evaluated at an extended baseline period during the first three months of APD in daily, weekly or monthly intervals for the prediction of technique failure (death or transfer to hemodialysis) and major adverse peritoneal events (MAPE, first occurrence of either PD-associated peritonitis or transfer to hemodialysis). This analysis was conducted with Kaplan Meier curves and Cox proportional hazard regression with empirical covariate selection ( compared to a stepwise forward selection procedure). Receiver operating characteristic analysis was conducted to analyze model performance and calculate area under the curve (AUC) measurements with respective 95% confidence intervals (95% CIs), sensitivity, specificity, and to find optimal thresholds for endpoint prediction in selected models. Results A total of 171/308 (56%) of patients treated with APD for home dialysis for 2.5 ± 1.9 years at mean (± standard deviation) were included. The analyzed patients were in 61% male, 54 ± 15 years of age at mean, and in 27% diabetic. 29% of patients were transferred to hemodialysis, and 29% of patients died on APD, corresponding to an all-cause technique failure-rate of 58%. Daily and weekly machine-readout cycler ultrafiltration at baseline significantly (P = 0.04 and P = 0.02, respectively) predicted transfer to hemodialysis, with an AUC of 0.6. While gcUF at baseline displayed the same AUC, covariate-adjusted Cox regression resulted only in a predictive trend (P = 0.08). Surprisingly, daily prescribed glucose loads were significant predictors of MAPE in the empirically adjusted and covariate forward selection procedure models (P = 0.03 and P = 0.02), with an AUC of 0.68. In addition, daily glucose loads were higher at baseline in patients who died on APD than in patients transferred to HD later during their treatment course (P = 0.05). Conclusion These data support the value of extended baseline measures, such as treatment response measures (as direct machine readouts) and prescription data for potential stratification of patients on APD with higher risk for adverse treatment trajectories and outcomes. Adding prescription data (such as the daily glucose load) to remote cloud-based APD analysis software thereby holds the potential to improve patient outcomes by providing the hospital-based dialysis team with the necessary toolkit for timely and rigorous treatment analysis and subsequent intervention.

Abstract Background and Aims Carry Life UF is a novel peritoneal dialysis (PD) technology for improved fluid management using steady concentration PD (SCPD). The Carry Life UF treatment starts with a manual peritoneal fill of a 1.36% glucose PD fluid, followed by a 5-hour treatment where small amounts of glucose are continuously added to maintain a stable intraperitoneal glucose concentration, thereby enabling effective ultrafiltration (UF) throughout the duration of the dwell. A recent in-center clinical study using the Carry Life UF system demonstrated increased UF volumes, more efficient use of glucose (increased UF/gram of glucose absorbed), and greater sodium removal with the Carry Life UF treatments compared with a 2.27% glucose continuous ambulatory PD (CAPD) dwell (CJASN 2024; 19: 224–32). The aim of this study is to compare efficacy and safety of the Carry Life UF system with a standard CAPD prescription in the home setting. Method A prospective, multicenter (Italy, Sweden, the UK), randomized, crossover study where 19 adult participants will complete the investigation. End-stage kidney disease patients with a CAPD prescription of 2–4 exchanges per day, unchanged for a minimum of two weeks, including at least one 2.27% glucose dwell daily, will be eligible for the study. After inclusion, an in-clinic dose determination phase will be performed. A 2.27% glucose peritoneal equilibration test will be performed for determination of peritoneal solute transfer rate, followed by two Carry Life UF treatments (11 g/h and 15 g/h glucose dose). The in-clinic phase is followed by the home treatment phase, where participants will be randomized to start with the control arm or the Carry Life UF arm, each of four weeks. During the control arm, participants will receive their standard CAPD treatment, including at least one 2.27% glucose dwell daily. During the Carry Life UF arm, one 2.27% glucose dwell will be replaced by a Carry Life UF treatment (11 g/h or 15 g/h glucose dose) three days per week. The remaining four days of the week, one 2.27% glucose dwell per day will be replaced by a 1.36% glucose dwell to avoid excessive UF (Fig. 1). Results The primary endpoint is UF volume, comparing the control CAPD 2.27% glucose dwell with the Carry Life UF treatment, measured at two specific treatments during each arm of the home treatment phase. An increase in UF volume with the Carry Life UF treatment vs. the control CAPD dwell of ≥ 250 mL is considered clinically relevant. The mean difference per patient will be determined and a t-test will be used to show superiority. Secondary endpoints are adverse event rates, peritoneal sodium removal, glucose UF efficiency, and peak dialysate glucose concentration. Conclusion This study sets out to evaluate a novel PD technology based on SCPD in the home setting. The execution of the study in the home environment entails challenges both in ensuring accurate endpoint data and in providing necessary support to the participants in the use of the technology. The protocol has been carefully designed to consider important parameters for precise UF volume measurements, and provides detailed weighing and sampling instructions to the study team to ensure accurate data quality and consistency between study centers. Research nursing support will be provided for training of participants and to support endpoint data collection in the participants’ home. Device trials in the home environment typically cause a considerable burden for participants with respect to time and effort. In this study participants are restricted to their homes during the 5-hour intervention treatments (12 times during four weeks) and are requested to complete a daily PD diary over eight weeks. Due to the significant burden associated with the study and to enable a smooth recruitment process, participants will be offered a fair compensation, in accordance with local regulations. Trial registration number NCT05874804 (ClinicalTrials.gov).

Introduction: Chronic kidney disease (CKD) significantly impacts global health, with dialysis patients often experiencing reduced quality of life. Incremental start peritoneal dialysis (INPD) has emerged as a promising individualized treatment strategy, offering potential benefits for both patient outcomes and environmental sustainability compared to the standard peritoneal dialysis (STPD). This study aimed to evaluate the impact of incremental start continuous ambulatory peritoneal dialysis (CAPD) on quality of life, clinical outcomes, and environmental metrics, such as plastic waste generation, compared to conventional CAPD. Methods: A multicenter study involving two groups (incremental start CAPD – INPD and standard dose conventional CAPD – STPD groups) was conducted. The baseline and 6-month follow-up data were collected, including laboratory parameters, treatment-related plastic waste, glucose load, residual renal function, and quality of life assessed using the Kidney Disease Quality Of Life Short Form (KDQOL-SF). Results: There was no statistically significant difference in median age and gender between the two groups (p > 0.05). In the third month of the study, a significant difference was observed in peritoneal equilibrium test ultrafiltration volume, with higher values in the STPD group (p = 0.020). There were no statistically significant differences between study groups according to permeability groups (p = 0.714) or KtV (p = 0.743). In the sixth month of the study, the INPD group demonstrated significantly better residual renal function (p < 0.001) and reduced weekly polypropylene and polyvinyl chloride plastic waste (p < 0.001) and glucose load (p < 0.001) in both the baseline and sixth months of the study. KDQOL-SF scores were significantly higher in the INPD group (p < 0.001). Conclusion: INPD demonstrated superior outcomes in maintaining residual renal function, reducing treatment burden, and improving quality of life while significantly lowering environmental impact compared to STPD. These findings support the adoption of INPD as an individualized and sustainable strategy in CKD management. Further research is needed to validate these findings in larger cohorts and explore long-term outcomes.

Empagliflozin and Ultrafiltration Volume in Patients Undergoing Peritoneal Dialysis

Introduction: Unwanted glucose exposure and absorption during peritoneal dialysis (PD) remain clinical challenges. Recent studies have attempted to reduce glucose absorption in PD via use of selective sodium-glucose cotransporter 2 (SGLT2) inhibitors, but results have been inconsistent and even paradoxical. We aimed to (i) explore whether both SGLT1 and SGLT2 are expressed and their respective anatomical localizations and proportions in the peritoneum and (ii) elucidate whether dual SGLT1/SGLT2 inhibition could reduce glucose absorption and improve ultrafiltration using a uremia chronic PD rat model. Methods: Twenty-four male Sprague-Dawley rats were randomly divided into four groups (each n = 6): the sham operation group, uremia group, uremia PD group, and sotagliflozin-treated group (a dual SGLT1+2 inhibitor). The expression levels of both SGLT1 and SGLT2 were determined by immunohistochemistry and Western blot analysis. Peritoneal transport function was monitored via a peritoneal equilibration test. Results: Both SGLT1 and SGLT2 are comparably expressed in the rat peritoneum and are prominently located in the vascular endothelium and peritoneal mesothelium. Compared with sham controls, uremia rats presented significantly increased expressions of both SGLT1 and SGLT2, and their expressions were further significantly increased after high-glucose PDF exposure for 5 weeks but markedly reversed by sotagliflozin cotreatment. Compared with the sham controls, uremia rats were characterized by greater glucose absorption, increased blood glucose levels, a lower D/D0 glucose ratio, a higher D/P cr ratio, a higher D/P urea ratio, and less net ultrafiltration. After infusion of high-glucose PDF for 5 weeks, these changes were more marked and were substantially ameliorated by sotagliflozin cotreatment. Conclusions: High-glucose PDF significantly increased the peritoneal expressions of both SGLT1 and SGLT2, which in turn facilitated more glucose absorption, eventually leading to a vicious cycle. Sotagliflozin may emerge as a novel strategy in PD to reduce glucose diffusion and enhance ultrafiltration.

This study aimed to assess the extent of vitamin B1 and B6 vitamer loss during a single peritoneal dialysis (PD) session using a combination of chromatographic techniques and chemometric analysis. Dialysis effluent samples were collected from 41 PD patients (22 on continuous ambulatory peritoneal dialysis (CAPD) and 19 on automated peritoneal dialysis (APD)) during a standardised peritoneal equilibration test. Concentrations of thiamine monophosphate, thiamine diphosphate (ThDP), pyridoxine, pyridoxal (PL), and pyridoxamine were determined using high-performance liquid chromatography with a fluorescence detector. The analytical method was validated in terms of sensitivity, linearity, accuracy, and recovery. Multiple regression analysis was employed to identify potential clinical and demographic predictors of vitamin washout. All vitamers except pyridoxal 5-phosphate (PLP) were detectable in dialysis effluents. ThDP exhibited the greatest loss among the B1 forms (ca. 0.05-0.57 mg/24 h), while PL exhibited the most significant loss among the B6 forms (ca. 0.01-0.19 mg/24 h). Vitamin losses varied depending on the dialysis modality (continuous ambulatory peritoneal dialysis, or CAPD, versus automated peritoneal dialysis, or APD) and the peritoneal transport category. Regression analysis identified body weight, haemoglobin, and haematocrit as independent predictors of ThDP washout (R2 = 0.58). No statistically robust models were established for the other vitamers. Even short medical procedures (such as single PD) can result in measurable losses of water-soluble vitamins, particularly ThDP and PL. The results emphasise the importance of personalised vitamin supplementation for PD patients and suggest that body composition and haematological parameters significantly influence the loss of thiamine.

There is a large person-to-person variability in ultrafiltration volume with peritoneal dialysis (PD), most of which cannot be accounted for by demographic and clinical differences. Herein we tested the hypothesis that common genetic variants are associated with peritoneal ultrafiltration and explored one mechanistic pathway identified by genetic studies. We generated estimates of heritability and undertook genome-wide and gene-wise studies, adjusted for peritoneal solute transfer rate (PSTR), to test associations of genetic variation with ultrafiltration on peritoneal equilibration test (PET) done at PD initiation in 2723 participants in the international Bio-PD study. We used a mouse model of PD to study the mechanistic basis for the association of PTGES gene with peritoneal ultrafiltration. PET was done at a median of 61 days (IQR 38-118) from PD start with a median 4-hour ultrafiltration volume of 250 mL (IQR 25-465). The heritability of peritoneal ultrafiltration was estimated to be 50% (p=0.001). In single nucleotide variant (SNV)-wise multi-ancestry GWAS using TRACTOR software, one SNV reached genome-wide significance in participants with European local ancestry (rs72631501, CRK intron, p=2.6x10-8) and one in participants with South Asian local ancestry (rs1416265, intergenic, p=4.2x10-8). Gene-wise analyses showed significant association of 21 genes at false discovery rates (FDRs) <0.10 in the European strata, notably PTGES (FDR=0.053), SLC24A3 (FDR=0.0003) and CRK (FDR=0.04). SLC24A3 remained significant (FDR=0.03) in meta-analysis of the four ancestry strata. Using scRNAseq, PTGES localized in peritoneal adipocytes. In a mouse PD model, pharmacological modulation of PTGES altered dialysate prostaglandin E2 (PGE2) levels with changes in adipocyte volume, peritoneal small solute transfer rate, and ultrafiltration volume. Common genetic variants accounted for a substantial proportion of the variability in peritoneal ultrafiltration with potential associations with 21 genes, including CRK, PTGES and SLC24A3. Functional studies substantiated a potential role for PTGES/PGE2 in regulating peritoneal ultrafiltration.

BackgroundTraditional markers of dialysis adequacy in peritoneal dialysis (PD) correlate poorly with both patient symptoms and outcomes, and residual kidney function remains the better determinant of each. Largely in response to these findings, guidelines now recommend focussing on patient-reported outcome measures (PROMs) in addition to assessing dialysis adequacy, where they have been shown to predict mortality, technique survival and hospitalisations. We aim to assess whether symptom burden measured by Palliative care Outcome Scale Symptom (POS-S)-renal questionnaire correlate with traditional markers of dialysis adequacy and is associated with future patient outcomes.HypothesisWe hypothesise that the POS-S renal score does not correlate with traditional markers of dialysis adequacy but that it might be associated with future outcomes including mortality, technique survival and hospitalisations.MethodThis was a retrospective study on adult PD patients who underwent a POS-S-renal questionnaire within 2-weeks of their routine Peritoneal Equilibrium Test (PET)-Adequest test. We assessed for the association between POS-S renal scores with adequacy measures (Kt/V and creatinine clearance or CCr) and whether POS-S renal scores were associated with future outcomes (remaining on PD, transition to haemodialysis, kidney transplantation or death on PD).ResultsThere were 107 patients with at least one paired PET-Adequest and POS-S renal questionnaire. There was no correlation between markers of dialysis adequacy (CCr and Kt/V) and symptom burden measured by POS-S renal questionnaire. Higher symptom burden was associated with less favourable outcomes including technique failure, hospitalisations and death (p < 0.05). There was also an association between a higher symptom burden and a lower serum albumin level (p < 0.001).ConclusionThere was no association between markers of dialysis adequacy and the POS-S renal score; however, a higher POS-S renal score was associated with technique failure, hospitalisations and death compared to traditional markers. The measurement of PROMs may provide a beneficial addition to dialysis assessment in routine PD care.Clinical trial numberNot applicable.

The main treatment for end-stage renal disease (ESRD) is renal replacement therapy, among which peritoneal dialysis (PD) is easy to perform, inexpensive, and widely used. The internationally adopted Peritoneal Equilibration Test (PET) categorizes peritoneal function into four types based on the dialysate-to-plasma creatinine ratio (D/Pcr). In some patients undergoing long-term PD, changes in peritoneal function lead to a decline in dialysis adequacy, which ultimately results in withdrawal from PD. Among these patients, those with high-transport peritoneal function exhibit higher mortality rates and poorer prognoses compared to patients with low-transport peritoneal function. However, PET fails to identify underlying pathologies (e.g., fibrosis, inflammation). Similarly, dialysis adequacy tests also fail to reveal the underlying causes of changes in dialysis adequacy. Therefore, early identification of the underlying causes of peritoneal function changes and timely clinical interventions may prolong the duration of PD. This review lists biomarkers related to peritoneal transport function that may indicate the causes of altered peritoneal function and could guide clinical treatment protocols in the future.

Background/Objectives: Phosphate level is a critical factor in the health of dialysis patients, as it is linked to cardiovascular risk. In peritoneal dialysis (PD), phosphate removal is related to residual kidney function, dietary intervention, and the ability of the visceral peritoneum to transport phosphate. The role of dialysis prescriptions in phosphate management is not sufficiently enhanced. Standardizing a phosphate removal propensity marker could optimize the peritoneal dialytic program. Our preliminary report aims to evaluate a simple model of phosphate handling and to assess which marker during the peritoneal equilibration test (PET) could better describe the propensity of phosphate removal through the peritoneal membrane. Methods: We hypothesized a simple two-compartment model to describe phosphate removal driven by diffusion. We performed an explorer study on 10 PD patients to assess the reliability of the two-compartment model. In each patient, we evaluated the basal condition and performed a PET with 2 L of 3.86% glucose exchange to assess phosphate handling. We collected blood and peritoneal effluent samples at the beginning of the test (t0), after 1 h (t1), and after 4 h (t4). We proposed and examined the following biomarkers: the ratio between dialysis effluent phosphate and plasma at t4 (PHO-D/P4); the difference between dialysis effluent phosphate at t0 and t4 (PHOΔd0-d4); and phosphate permeability–area product at t4 (PHO-PxA4). Results: 9 men and one woman with a mean age of 58.7 ± 16.7 years and a mean dialysis vintage of 25 ± 18.3 months were enrolled. The PHO-D/P4 mean was 0.68 ± 0.18, the PHO-Δd0-d4 median was 0.89 mmol/L [0.7–1.19], and the PHO-PxA4 mean was 1.7 ± 0.85. PHO-D/P4was significantly related to creatinine D/P4 (beta 1.49, p &lt; 0.001), PHO-Δd0-d4 was significantly influenced by plasma phosphate at t0 (beta 0.56, p &lt; 0.001), and the PHO-PxA4 was significantly influenced by ultrafiltration (beta 0.003, p &lt; 0.001). Conclusions: In our two-compartment model, we observed the independence of the PHO-D/P4marker, which could serve as a potential marker for standardizing phosphate handling. However, PHO-Δd0-d4 and PHO-PxA4 normalized by plasma phosphate at t0 and ultrafiltration rate were able to reserve a potential good performance as markers in phosphate handling standardization.

Background The peritoneal equilibration test (PET) assesses peritoneal membrane characteristics in patients undergoing peritoneal dialysis (PD). This study aims to assess the prevalence of PET testing, describe membrane characteristics, and evaluate PET’s impact on PD prescriptions and patient outcomes. Materials and Methods This retrospective cohort study included all PD patients treated at our center between 2006 and 2023. We analyzed membrane characteristics, PET result-based changes in PD prescriptions, and PET prognostic value for PD discontinuation, cardiovascular events, mortality, and hospitalizations. Results Of 240 patients, 82 (33%) had a PET, with a decrease in prevalence after 2017. Membrane characteristics differed between patients with fast and slow peritoneal solute transfer rates, influencing PD prescription, particularly ultrafiltration management. Indication-based PET led to more targeted prescription adjustments. FTs tend to be hospitalized more frequently than STs (74% vs. 56%, p=0.115). Cardiovascular events affected 50.7% of patients, with no significant difference between the two groups (p=0.844). We saw that 30% of patients discontinued PD, with no notable difference between RTs and STs. All-cause mortality was recorded in 37.8% of patients, with more among FTs (40%) compared to STs (30%), although this difference was not statistically significant (p=0.392). Conclusion Indication-based PET allows tailored adjustments in PD prescriptions without compromising patient outcomes. PET remains a valuable tool with prognostic value for PD management.

Plain Language SummaryPeritoneal dialysis (PD) is a treatment for kidney failure that removes waste and excess fluids from the body using the patient’s own peritoneal membrane as a natural filter. Over time, the function of this membrane can change, affecting how well PD works. The peritoneal equilibration test (PET) measures how efficiently the peritoneal membrane filters waste. However, how PET results change over time and whether certain biological markers in the drained fluid can help predict these changes remain unclear. This study tracked PET changes in PD patients from 2016 to 2020 and examined their association with serious complications, such as transfer to hemodialysis or death. Patients were divided into four groups based on how their PET results evolved over time. Researchers also measured specific biological markers (MMP2 and PAI-1) in PD fluid to determine whether they could predict future changes in PET results. A machine learning model was used to analyze the data and improve predictions. The study found that patients with persistently high or increasing transport rates had a greater risk of transferring to hemodialysis or death. Those with high levels of the MMP2 and PAI-1 biomarkers in their PD fluid were more likely to experience these changes. The machine learning model accurately predicted which patients would develop high transport rates, highlighting its potential use in identifying at-risk patients early. Monitoring PET changes and biomarkers could support timely clinical decisions, helping optimize PD management.

Introduction: The association between anemia and peritoneal dialysis (PD) withdrawal in patients with stable PD remains poorly established. Herein, we investigated the relationship between anemia and PD withdrawal in patients with stable PD. Materials and Methods: We included 43 patients undergoing PD for at least 6 months between October 2011 and December 2022. Patients were categorized based on their hemoglobin (Hb) levels at the time of their first peritoneal equilibration test (PET) during the study period as follows: Hb ≥ 11 g/dL and Hb &lt; 11 g/dL. The PD withdrawal rates were compared between these groups. Patients were followed up until death or 31 July 2023. Results: During the follow-up, 36 patients discontinued treatment. Patients with Hb &lt; 11 g/dL had a significantly higher PD withdrawal rate than those with Hb ≥ 11 g/dL. Cox proportional hazards analysis identified Hb level as a risk factor for PD withdrawal. Furthermore, Hb levels negatively correlated with the annual decline in urine volume. Conclusions: Our findings suggest anemia as a predictor of PD withdrawal in patients with stable PD. The negative correlation between Hb levels and the annual decline in urine volume implies that anemia may contribute to PD withdrawal via the deterioration of residual renal function.