Corrigendum: Relationship between serum iPTH and peritonitis episodes in patients undergoing continuous ambulatory peritoneal dialysis

[This corrects the article DOI: 10.3389/fendo.2023.1081543.].

Relationship between serum iPTH and peritonitis episodes in patients undergoing continuous ambulatory peritoneal dialysis

BACKGROUND

Peritonitis is considered as one of the most serious complications that cause hospitalization in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). There is limited evidence on the impact of the parathyroid hormone (PTH) on the first peritoneal dialysis (PD)-associated peritonitis episode. We aimed to investigate the influence of serum intact parathyroid hormone (iPTH) on peritonitis in patients undergoing PD.

METHODS

This was a retrospective cohort study. Patients undergoing initial CAPD from a single center in China were enrolled. The baseline characteristics and clinical information were recorded. The primary outcome of interest was the occurrence of the first PD-associated peritonitis episode. Five Cox proportional hazard models were constructed in each group set. In group set 1, all participants were divided into three subgroups by tertiles of the serum concentration of iPTH; in group set 2, all participants were divided into three subgroups based on the serum concentration of iPTH with 150 pg/ml interval (<150, 150-300, and >300 pg/ml). Hazard ratios and 95% confidence intervals (CIs) were calculated for each model. The multivariate linear regression analysis elimination procedure assessed the association between the clinical characteristics at baseline and the iPTH levels. Restricted cubic spline models were constructed, and stratified analyses were also conducted.

RESULTS

A total of 582 patients undergoing initial PD (40% women; mean age, 45.1 ± 11.5 years) from a single center in China were recruited. The median follow-up duration was 25.3 months. Multivariate Cox regression analysis showed that, in the fully adjusted model, a higher serum iPTH level (tertile 3, iPTH >300 pg/ml) was significantly associated with a higher risk of PD-associated peritonitis at 3 years [tertile 3: hazard ratio (HR) = 1.53, 95%CI = 1.03-2.55, p = 0.03; iPTH > 300 pg/ml: HR = 1.57, 95%CI = 1.08-2.27, p = 0.02]. The hazard ratio for every 100 pg/ml increase in serum iPTH level was 1.12 (95%CI = 1.05-1.20, p < 0.01) in the total cohort when treating iPTH as a continuous variable.

CONCLUSIONS

An elevated iPTH level was significantly associated with an increased risk of peritonitis in patients undergoing CAPD.

The estimation of protein equivalents of total nitrogen in Chinese CAPD patients: an explanatory study

Objective

The protein equivalent of total nitrogen appearance (PNA) formula, based on the urea nitrogen appearance (UNA), is popularly used by stable continuous ambulatory peritoneal dialysis (CAPD) patients to estimate dietary daily protein intake (DPI). However, we found that the estimated DPI was higher than that directly evaluated from the dietary records of most of our CAPD patients. Therefore, in the present study, we tried to determine possible bias in PNA estimation by UNA with a nitrogen balance study of our CAPD patients.

Methods

Thirty-one CAPD patients with stable clinical conditions were included. Their 3-day dietary records were reviewed by a dedicated dietitian to calculate their energy, protein, and nitrogen intake (NI). The nitrogen removal (NR) from urine and dialysate was measured by the Kjeldahl technique. Then, we calculated the proportion of urea nitrogen appearance (UNA) in total nitrogen appearance (TNA) and analyzed the possible factors that could affect this proportion.

Results

Among these patients, 17 males and 14 females, the mean age was 64.19 ± 12.42, and the dialysate drainage volume was 6700 (2540) ml/day. The percentage of UNA in TNA was 63.22 ± 6.66%. Compared with the other classic nitrogen balance studies in the CAPD population, the protein nitrogen and other nonurea nitrogen losses in this study were all lower. Based on these 31 nitrogen balance studies, we proposed a pair of new equations to estimate PNA by UNA. (1) PNA = 9.3 + 7.73 UNA; (2) PNA = PNPNA + TPL = 6.7 + 7.28 UNA + TPL.

Conclusion

Our study suggested that the PNA formula generated from previous European studies overestimated DPI in our CAPD patients.

Normalized Protein Catabolic Rate Is a Superior Nutritional Marker Associated With Dialysis Adequacy in Continuous Ambulatory Peritoneal Dialysis Patients

Introduction: Current knowledge of the relationship between normalized protein catabolic rate (nPCR) and dialysis adequacy is limited. Our study aimed to explore the potential relationship between nPCR and dialysis adequacy.

Methods: In this cross-sectional study, we analyzed the association of nPCR with peritoneal dialysis adequacy in 266 continuous ambulatory peritoneal dialysis (CAPD) patients (mean age 48.6 ± 13.1 years; 50.8% male). The patients were divided into two groups: a dialysis inadequacy group (total weekly Kt/V urea < 1.70) and a dialysis adequacy group (total weekly Kt/V urea≥1.70). We then analyzed the correlation between dialysis adequacy and the patients' primary cause of end-stage renal disease, nutritional and inflammatory markers, and biochemical parameters. Multivariable logistic regression analysis was also used to identify risk factors for inadequate dialysis.

Results: We observed a significantly higher level of nPCR (0.98 ± 0.22 vs. 0.79 ± 0.18 g/kg/day, p < 0.001) in the dialysis adequacy group, whereas we observed no significant differences among other nutritional markers such as albumin, prealbumin, and transferrin. Correlation analyses revealed that dialysis adequacy was positively associated with residual glomerular filtration rate (rGFR), hemoglobin, serum calcium, and body mass index (BMI), while dialysis adequacy was negatively associated with leak-protein, uric acid, high-sensitivity C-reactive protein, interleukin-6, and serum phosphorus. Furthermore, a logistic regression analysis revealed that gender (male), nPCR <0.815 g/kg/day, higher weight, and rGFR <2.43 mL/min/1.73 m² were independent risk factors for inadequate dialysis.

Conclusion: Nutritional status is closely associated with dialysis adequacy. Among common nutritional markers, nPCR may be superior for predicting CAPD dialysis adequacy. Gender (male), nPCR <0.815 g/kg/day, higher weight, and rGFR <2.43 mL/min/1.73 m² are independent risk factors for dialysis inadequacy in CAPD patients.

Intraperitoneal Cefepime Monotherapy Versus Combination Therapy of Cefazolin Plus Ceftazidime for Empirical Treatment of CAPD-Associated Peritonitis: A Multicenter, Open-Label, Noninferiority, Randomized, Controlled Trial

RATIONALE & OBJECTIVE

Compared to combination therapy, intraperitoneal (IP) cefepime monotherapy for continuous ambulatory peritoneal dialysis (CAPD)-associated peritonitis may provide potential benefits in lowering staff burden, shortening time-consuming antibiotic preparation, and reducing bag contamination risk. This study sought to evaluate whether cefepime monotherapy is noninferior to combination regimens.

STUDY DESIGN

Multicenter, open-label, noninferiority, randomized, controlled trial.

SETTING & PARTICIPANTS

Adult incident peritoneal dialysis (PD) patients with CAPD-associated peritonitis in 8 PD centers in Thailand.

INTERVENTIONS

Random assignment to either IP monotherapy of cefepime, 1g/d, or IP combination of cefazolin and ceftazidime, 1g/d, both given as continuous dosing.

OUTCOMES

Primary end point: resolution of peritonitis at day 10 (primary treatment response).

SECONDARY OUTCOMES

initial response (day 5), complete cure (relapse/recurrence-free response 28 days after treatment completion), relapsing/recurrent peritonitis, and death from any cause. Noninferiority would be confirmed for the primary outcome if the lower margin of the 1-sided 95% CI was not less than-10% for difference in the primary response rate. A 2-sided 90% CI was used to demonstrate the upper or lower border of the 1-sided 95% CI.

RESULTS

There were 144 eligible patients with CAPD-associated peritonitis, of whom 70 and 74 patients were in the monotherapy and combination-therapy groups, respectively. Baseline demographic and clinical characteristics were not different between the groups. The primary response was 82.6% in the monotherapy group and 81.1% in the combination-therapy group (treatment difference, 1.5%; 90% CI, -9.1% to 12.1%; P=0.04). There was no significant difference in the monotherapy group compared with the combination-therapy group in terms of initial response rate (65.7% vs 60.8%; treatment difference, 4.9%; 95% CI, -10.8% to 20.6%; P=0.5) and complete cure rate (80.0% vs 80.6%; treatment difference, -0.6%; 95% CI, -13.9% to 12.8%; P=0.7). Relapsing and recurrent peritonitis occurred in 4.6% and 4.6% of the monotherapy group and 4.2% and 5.6% of the combination-therapy group (P=0.9and P=0.8, respectively). There was nominally higher all-cause mortality in the monotherapy group (7.1% vs 2.7%; treatment difference, 4.4%; 95% CI, -2.6% to 11.5%), but this difference was not statistically significant (P = 0.2).

LIMITATION

Not double blind.

CONCLUSIONS

IP cefepime monotherapy was noninferior to conventional combination therapy for resolution of CAPD-associated peritonitis at day 10 and may be a reasonable alternative first-line treatment.

FUNDING

This study is supported by The Kidney Foundation of Thailand (R5879), Thailand; Rachadaphiseksompotch Fund (RA56/006) and Rachadaphicseksompotch Endorsement Fund (CU-GRS_61_06_30_01), Chulalongkorn University, Thailand; National Research Council of Thailand (156/2560), Thailand; and Thailand Research Foundation (IRG5780017), Thailand.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT02872038.

An Inverse Relationship between Hyperuricemia and Mortality in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

Background: The results have been inconsistent with regards to the impact of uric acid (UA) on clinical outcomes both in the general population and in patients with chronic kidney disease. The aim of this study was to study the influence of serum UA levels on mortality in patients undergoing continuous ambulatory peritoneal dialysis. Methods: Data on 492 patients from a single peritoneal dialysis unit were retrospectively analyzed. The mean age of the patients was 53.5 ± 15.3 years, with 52% being female (n = 255). The concomitant comorbidities at the start of continuous ambulatory peritoneal dialysis (CAPD) encompassed diabetes mellitus (n = 179, 34.6%), hypertension (n = 419, 85.2%), and cardiovascular disease (n = 186, 37.9%). The study cohort was divided into sex-specific tertiles according to baseline UA level. A Cox proportional hazard model was used to calculate hazard ratios (HRs) of all-cause, cardiovascular, and infection-associated mortality with adjustments for demographic and laboratory data, medications, and comorbidities. Results: Multivariate Cox regression analysis showed that, using UA tertile 1 as the reference, the adjusted HR of all-cause, cardiovascular, and infection-associated mortality for tertile 3 was 0.4 (95% confidence interval (CI) 0.24⁻0.68, p = 0.001), 0.4 (95% CI 0.2⁻0.81, p = 0.01), and 0.47 (95% CI 0.19⁻1.08, p = 0.1). In the fully adjusted model, the adjusted HRs of all-cause, cardiovascular, and infection-associated mortality for each 1-mg/dL increase in UA level were 0.84 (95% CI, 0.69⁻0.9, p = 0.07), 0.79 (95% CI, 0.61⁻1.01, p = 0.06), and 0.79 (95% CI, 0.48⁻1.21, p = 0.32) for men and 0.57 (95% CI, 0.44⁻0.73, p < 0.001), 0.6 (95% CI, 0.41⁻0.87, p = 0.006), and 0.41 (95% CI, 0.26⁻0.6, p < 0.001) for women, respectively. Conclusions: Higher UA levels are associated with lower risks of all-cause, cardiovascular and infection-associated mortality in women treated with continuous ambulatory peritoneal dialysis.

Peritoneal dialysis catheter leakage following intermittent vacuum therapy

Peripheral arterial disease and diabetic foot syndrome are common comorbidities in dialysis patients. These conditions are treated with intermittent vacuum therapy in order to increase angiogenesis and perfusion. Some devices encase the lower extremities up to the abdomen. Here we report the case of a patient who had performed peritoneal dialysis for 2 years without complications. Following postoperative intermittent vacuum therapy, he presented with extensive catheter leakage. Ultimately the patient had to be switched to haemodialysis and the catheter had to be removed. This case exemplifies that peritoneal dialysis patients have a substantial risk for noninfectious catheter-related complications using vacuum therapy.

Relationship between uric acid and technique failure in patients on continuous ambulatory peritoneal dialysis: a long-term observational cohort study

OBJECTIVES

Uric acid (UA) is the product of purine or nucleotide metabolism via the pathway of xanthine oxidase or xanthine dehydrogenase. Although epidemiological studies assessing the role of UA in cardiovascular disease or mortality have produced inconsistent results, the correlation between UA and technique failure in patients on continuous ambulatory peritoneal dialysis (CAPD) remains to be assessed.

DESIGN

A retrospective cohort study.

SETTING

Patients starting CAPD between 2001 and 2009 in a single centre in Taiwan.

PARTICIPANTS

A total of 371 patients on CAPD.

PRIMARY OUTCOME MEASURES

All-cause and peritonitis-related technique failure.

RESULTS

A cohort of 371 participants (43.9% male) was enrolled in the study with a mean age of 55.7±15.9 years at the start of CAPD. During the study period, technique failure occurred in 41 (34.4%) patients in the hyperuricaemia group compared with 49 (19.4%) in the normouricaemia group (p=0.003). In the multivariate Cox regression models, hyperuricaemia at baseline was significantly associated with both a higher risk of technique failure (HR 1.24; 95% CI 1.09 to 1.42, p=0.001) and peritonitis-related technique failure (HR 1.29; 95% CI 1.07 to 1.57, p=0.008).

CONCLUSIONS

UA was shown to be associated with all-cause and peritonitis-related technique failure in our study. Patients on CAPD with hyperuricaemia should be closely monitored and strategies of increasing survival on CAPD should be taken.

Comparative outcomes between continuous ambulatory and automated peritoneal dialysis: a narrative review

Automated methods for delivering peritoneal dialysis (PD) to persons with end-stage renal disease continue to gain popularity worldwide, particularly in developed countries. However, the endeavor to automate the PD process has not been advanced on the strength of high-level evidence for superiority of automated over manual methods. This article summarizes available studies that have shed light on the evidence that compares the association of treatment with continuous ambulatory PD or automated PD (APD) with clinically meaningful outcomes. Published evidence, primarily from observational studies, has been unable to demonstrate a consistent difference in residual kidney function loss rate, peritonitis rate, maintenance of euvolemia, technique survival, mortality, or health-related quality of life in individuals undergoing continuous ambulatory PD versus APD. At the same time, the future of APD technology appears ripe for further improvement, such as the incorporation of voice commands and expanded use of telemedicine. Given these considerations, it appears that patient choice should drive the decision about PD modality.

Zinc status in patients with chronic renal failure on conservative and peritoneal dialysis treatment

BACKGROUND AND AIM

The physiological mechanisms regulating zinc homeostasis in humans have been elucidated and described, but the knowledge of zinc status and zinc distribution in the tissues and in the different biological compartments of patients with conservatively treated chronic renal failure (CRF) and on peritoneal dialysis is still insufficient. This investigation examines and compares zinc content in urine, erythrocytes, plasma, and outflow dialysis solution in a group of continuous ambulatory peritoneal dialysis (CAPD) patients, a group of patients with CRF on conservative treatment and in healthy controls.

MATERIAL AND METHODS

Data from the last 6 months of 22 adult hemodialysis patients with a mean age of 61 ± 14 years were analyzed retrospectively. Dialysis vintage, normalized protein catabolic rate (nPCR), serum biochemical parameters, mid arm muscle circumference (MAMC) were determined as mean and standard deviation. Correlations between the variables were computed by coefficient p of Pearson.

RESULTS AND CONCLUSION

In patients on CAPD treatment (group 3) compared to healthy controls (group 1) plasma zinc level was diminished (р<0.05), while erythrocyte zinc elevated (р<0.01). The investigation found out difference between plasma, erythrocyte and urine levels of zinc between the patients with chronic renal failure (group 2) on conservative treatment and those treated by CAPD (group 3), which proves, that continuous ambulatory peritoneal dialysis influences redistribution of zinc in human organism "per se".

Comparison of Blood Pressure Control and Left Ventricular Hypertrophy in Patients on Continuous Ambulatory Peritoneal Dialysis (CAPD) and Automated Peritoneal Dialysis (APD)

This study aimed to investigate the influence of different peritoneal dialysis regimens on blood pressure control, the diurnal pattern of blood pressure and left ventricular hypertrophy in patients on peritoneal dialysis. Forty-four patients undergoing peritoneal dialysis were enrolled into the study. Patients were treated with different regimens of peritoneal dialysis: 26 patients on continuous ambulatory peritoneal dialysis (CAPD) and 18 patients on automated peritoneal dialysis (APD). All patients performed 24-hour ambulatory blood pressure monitoring (ABPM) and echocardiography. Echocardiography was performed for measurement of cardiac parameters and calculation of left ventricular mass index (LVMI). There were no significant differences in average of systolic and diastolic blood pressure during 24-hour, daytime, and nighttime between CAPD and APD groups. There were no significant differences in diurnal variation of blood pressure, systolic and diastolic blood pressure load, and LVMI between CAPD and APD groups. LVMI was associated with 24 hour systolic blood pressure load (r = 0.311, P < 0.05) and daytime systolic blood pressure load (r = 0.360, P < 0.05). In conclusion, this study found that there is no difference in blood pressure control, diurnal variation of blood pressure and left ventricular hypertrophy between CAPD and APD patients. The different peritoneal dialysis regimens might not influence blood pressure control and diurnal variation of blood pressure in patients on peritoneal dialysis.