Renin-angiotensin system blockers and residual kidney function loss in patients initiating peritoneal dialysis: an observational cohort study

Early Anuria in Incident Peritoneal Dialysis Patients: Incidence, Risk Factors, and Associated Clinical Outcomes

Rationale & Objective

The development of anuria has been linked to worse clinical outcomes in patients undergoing peritoneal dialysis (PD). Our objective was to investigate the incidence, risk factors, and associated clinical outcomes of anuria within the first year after starting PD.

Study Design

Retrospective cohort study.

Setting & Participants

Patients who started continuous ambulatory peritoneal dialysis at our center between 2006 and 2020 were included and followed up until January 31, 2023.

Exposure

Age, sex, diabetes, temporary hemodialysis, angiotensin-converting enzyme inhibitors (ACEis) or angiotensin II receptor blockers (ARBs), diuretics, baseline urine volume, serum albumin, daily glucose exposure, peritonitis, and incremental PD.

Outcomes

The primary outcome was early anuria, defined as 24-hour urine volume ≤100 mL within the first year of PD initiation. Secondary outcomes included all-cause mortality, cardiovascular disease mortality, technique failure, and peritonitis.

Analytical Approach

Cox proportional hazards model.

Results

A total of 2,592 patients undergoing continuous ambulatory peritoneal dialysis aged 46.7 ± 14.9 years were recruited. Among them, 58.9% were male, and 24.0% had diabetes. Within the first year of PD therapy, 159 (6.13%) patients developed anuria, with a median duration of 7.53 (interquartile range, 3.93-10.0) months. Higher baseline urine volume (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.90-0.97), higher serum albumin (HR, 0.92; 95% CI, 0.88-0.95), having diabetes before PD (HR, 0.57; 95% CI, 0.35-0.92), and prescribed incremental PD (HR, 0.27; 95% CI, 0.14-0.51) were associated with a reduced risk for early anuria, whereas a higher level of daily glucose exposure (HR, 1.01; 95% CI, 1.00-1.01) was identified as a risk factor for early anuria. Subgroup analyses showed that using ACEis or ARBs was linked to a lower risk of early anuria (HR, 0.25; 95% CI, 0.09-0.69) in diabetic patients. Treating early anuria as a time-dependent covariate, early anuria was associated with a higher risk for all-cause mortality (HR, 1.69; 95% CI, 1.23-2.32) and technique failure (HR, 1.43; 95% CI, 1.00-2.04) after adjusting for confounding factors.

Limitations

Single-center and observational study.

Conclusions

Among PD patients at a single center in China, early anuria was relatively uncommon but associated with an increased risk of mortality and PD technique failure. Incremental PD, higher baseline urine output and serum albumin, and lower daily glucose exposure were associated with a lower risk of early anuria. Clinical trials are needed to evaluate the optimal PD techniques to preserve residual kidney function and maximaze outcomes.

Clinical guideline on adequacy and prescription of peritoneal dialysis

In recent years, the meaning of adequacy in peritoneal dialysis has changed. We have witnessed a transition from an exclusive achievement of specific objectives -namely solute clearances and ultrafiltration- to a more holistic approach more focused to on the quality of life of these patients. The purpose of this document is to provide recommendations, updated and oriented to social and health environment, for the adequacy and prescription of peritoneal dialysis. The document has been divided into three main sections: adequacy, residual kidney function and prescription of continuous ambulatory peritoneal dialysis and automated peritoneal dialysis. Recently, a guide on the same topic has been published by a Committee of Experts of the International Society of Peritoneal Dialysis (ISPD 2020). In consideration of the contributions of the group of experts and the quasi-simultaneity of the two projects, references are made to this guide in the relevant sections. We have used a systematic methodology (GRADE), which specifies the level of evidence and the strength of the proposed suggestions and recommendations, facilitating future updates of the document.

Effects of ACEIs and ARBs on the Residual Renal Function in Peritoneal Dialysis Patients: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

In peritoneal dialysis (PD) patients, whether angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) could protect residual renal function is still controversial. To assess the effects of ACEIs and ARBs on the residual renal function and cardiovascular (CV) events in peritoneal dialysis patients, we performed a meta-analysis of randomized controlled trials.

MATERIALS AND METHODS

We searched PubMed, EMBASE, the Cochrane Library, the CNKI database, and the Wanfang database for relevant articles from database inception to November 30, 2019. Randomized controlled trials were included. The primary outcome was the decline in the residual renal function (RRF).

RESULTS

Thirteen trials with 625 participants were included in the meta-analysis. The average residual GFR declined by 1.79 ml/min per 1.73 m² in the ACEI/ARB group versus 1.44 ml/min per 1.73 m² in the placebo or active control group at 3 mo. The average residual GFR declined by 2.02 versus 2.06, 2.16 versus 2.72, and -0.04 versus 2.74 ml/min per 1.73 m² in the placebo or active control group at 6 months (mo), 12 mo, and 24 mo, respectively. The decline in residual GFR showed a significant difference between the ACEI/ARB group and the placebo or active control group at 12 mo (MD = -0.64 ml/min per 1.73 m²; 95% CI: -0.97~-0.32; I ² = 44%; P < 0.0001). No significant difference was observed in Kt/V, urinary protein excretion, weekly creatinine clearance, CV events, or serum potassium levels.

CONCLUSIONS

In the present study, we found that the use of ACEIs and ARBs, especially long-term treatment, decreased the decline of RRF in patients on PD. ACEIs and ARBs do not cause an additional risk of side effects.

Effectiveness of Renin-Angiotensin-Aldosterone System Blockade on Residual Kidney Function and Peritoneal Membrane Function in Peritoneal Dialysis Patients: A Network Meta-Analysis

We performed a network meta-analysis of randomised controlled trials (RCTs) and non-randomised studies in adult peritoneal dialysis patients to evaluate the effects of specific renin-angiotensin aldosterone systems (RAAS) blockade classes on residual kidney function and peritoneal membrane function. Key outcome parameters included the following: residual glomerular filtration rate (rGFR), urine volume, anuria, dialysate-to-plasma creatinine ratio (D/P Cr), and acceptability of treatment. Indirect treatment effects were compared using random-effects model. Pooled standardised mean differences (SMDs) and odd ratios (ORs) were estimated with 95% confidence intervals (CIs). We identified 10 RCTs (n = 484) and 10 non-randomised studies (n = 3,305). Regarding changes in rGFR, RAAS blockade with angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) were more efficacious than active control (SMD 0.55 [0.06–1.04] and 0.62 [0.19–1.04], respectively) with the protective effect on rGFR observed only after usage ≥12 months, and no differences among ACEIs and ARBs. Compared with active control, only ACEIs showed a significantly decreased risk of anuria (OR 0.62 [0.41–0.95]). No difference among treatments for urine volume and acceptability of treatment were observed, whereas evidence for D/P Cr is inconclusive. The small number of randomised studies and differences in outcome definitions used may limit the quality of the evidence.

Assessment of the effect of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in peritoneal dialysis patients: a systematic review and meta-analysis on clinical trials

Background

Renin-angiotensin system inhibitors (RASIs), either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, are widely used in patients with non-dialysis chronic kidney disease, as a renin-angiotensin system (RAS) blockade has renoprotective effects. Several studies show that preserving residual renal function is important for a better prognosis in peritoneal dialysis (PD) patients. Here, we systematically reviewed the beneficial or harmful effects of RAS blockade in PD patients.

Methods

PubMed, the Cochrane Library, Embase, the Ichushi web databases, and other resources were selected to search clinical guidelines, systematic reviews, and randomized controlled trials (RCT) published before April 14, 2017, using “peritoneal dialysis,” “angiotensin-converting enzyme inhibitors,” “angiotensin II type 1 receptor blockers,” and “randomized controlled trial” as keywords. Desired results were total mortality, technical survival, urine volume, residual renal function calculated byglomerular filtration rate(GFR), cardiovascular events, and anuria progression rate. The study protocol is registered in PROSPERO (International Prospective Register of Systematic Reviews) under the registration number CRD42018104106.

Results

Of a total of 339 studies, eight were identified as suitable for the analysis. Only one study was blinded, whereas the other seven studies were open-label. RASI appeared to preserve residual renal function, GFR (4 studies, 163 participants, mean difference [MD] 0.97 mL/min/1.73 m2, 95% confidence interval [CI] 0.49–1.44), and urine volume (6 studies, 194 participants, MD 142.56 mL 95% CI 25.42–259.69), although there were no beneficial effects of RASI on total mortality, technical survival, cardiovascular events, and anuria rate.

Conclusions

Our analysis found that RASIs contribute to preserving GFR and urine volume in PD patients. As the number of study participants is small, further studies with a larger sample size are required.

[Effect of dietary sodium intake on residual renal function in patients undergoing peritoneal dialysis: a prospective study of 33 cases]

OBJECTIVE

To explore the impact of dietary sodium-intake on residual renal function in patients undergoing peritoneal dialysis (PD).

METHODS

Thirty-three patients on PD with stable dialysis were regularly followed up for 12 months. The daily sodium intake of the patients was calculated based on the 3-day dietary record. Based on the mean daily sodium intake, the patients enrolled were divided into low-salt group (sodium intake≤3.0 g/day, 19 patients) and high-salt group (sodium intake&gt;3.0 g/day, 14 patients). The baseline data of the patients were recorded, and the indicators of residual renal function and peritoneal function were regularly tested. The patients were followed-up at 3-month intervals, and their urine volume, peritoneal ultrafiltration volume and other clinical indicators were recorded and the biochemical indexes were detected to evaluate the changes in the residual renal function and peritoneal function.

RESULTS

There was a positive correlation between the total sodium excretion and dietary sodium intake in these patients (r=0.536, P=0.0013), and sodium excretion by dialysis was positively correlated with their sodium intake (r=0.901, P=0.000). Regression analysis suggested that the total sodium excretion was correlated with dietary sodium intake (β=0.416, 95% CI: 0.170-0.666; P &lt; 0.0018); sodium excretion by dialysis was associated with dietary sodium intake (β=0.489, 95% CI: 0.395-0.582; P &lt; 0.001). The residual renal function was reduced by 17.48±11.22 L /(w·1.73 m²) in the low-salt group, as compared to 30.20±18.30 L /(w·1.73 m²) in the high-salt group (P=0.032). The reduction in the residual renal function was correlated with sodium intake in the PD patients (r=0.409, P=0.018). Multivariate regression analysis showed that sodium intake was an independent factor contributing to the reduction of residual renal function (β=14.646, 95% CI 7.426-21.866, P &lt; 0.001).

CONCLUSIONS

Sodium excretion by PD in patients with continuous ambulatory PD is positively correlated with their dietary sodium intake, which contribute to the decrease of residual renal function. A high dietary sodium intake may accelerate the reduction of residual renal function in these patients.