Roles of peritoneal clearance and residual kidney removal in control of uric acid in patients on peritoneal dialysis

The relationship between serum uric acid and gastrointestinal bleeding in peritoneal dialysis patients: a propensity score analysis

PURPOSE

Gastrointestinal bleeding is an important gastrointestinal complication among peritoneal dialysis patients and correlated with a higher risk of mortality. Increased uric acid levels are a significant complication for peritoneal dialysis patients and have been associated with an increased risk of hemorrhagic stroke. The objective of the present study was to investigate the relationship between serum uric acid levels and gastrointestinal bleeding in peritoneal dialysis patients.

METHODS

A total of 2498 peritoneal dialysis patients were recruited. Based on the optimal uric acid cutoff value, two groups of patients were divided. We constructed a propensity-score-matched population of 1762 patients by matching sex, age, and body mass index. Survival outcomes between the two groups were compared using adjusted Kaplan-Meier curves. We constructed the restricted cubic splines regression to assess the correlation between levels of uric acid and gastrointestinal bleeding. A multivariate Cox proportional hazards regression was performed to test whether higher levels of uric acid are an independent risk factor for gastrointestinal bleeding. We performed a forest plot to show interaction effects in different subgroups.

RESULTS

According to restricted cubic splines regression, uric acid levels were positively correlated with the risk of gastrointestinal bleeding events. After adjusted different confounding factors, patients with high levels of uric acid were prone to experience gastrointestinal bleeding (HR 1.868, 95%CI 1.001-3.486). In subgroups, the interaction between higher levels of uric acid and utilizing proton pump inhibitors was significant (P for interaction = 0.034). Further research found that taking proton pump inhibitors could decrease the risk of gastrointestinal bleeding in peritoneal dialysis patients accompanied high levels of uric acid.

CONCLUSION

The baseline high levels of uric acid are an independent risk factor for gastrointestinal bleeding in patients undergoing peritoneal dialysis.

Role of Peritoneal Equilibration Test in Assessing Folate Transport During Peritoneal Dialysis

OBJECTIVES

Low plasma folate levels have been reported in patients undergoing hemodialysis and peritoneal dialysis (PD) in clinical studies. However, folate transport has never been mentioned as a factor contributing to low plasma folate levels in patients undergoing PD. The peritoneal equilibrium test (PET) assesses the plasma creatinine level and glucose transport abilities. This study aimed to evaluate the association between plasma folate levels and folate transport during PD based on PET grades.

METHODS

This study recruited 50 patients who underwent PD for ≥3 months and were categorized according to PET grades. Data regarding plasma folate levels and dialysate folate were collected. The primary outcomes were the relationship between the PET grade and plasma folate level and between the PET grade and dialysate-to-plasma folate concentration ratio (D/P folate). Furthermore, the difference in the plasma folate level and D/P folate between men and women was assessed.

RESULTS

The plasma folate level and the D/P folate significantly differed among the 4 PET groups (both P < .001). PET grade was significantly negatively correlated with plasma folate levels (r = -0.56, P < .001) and positively correlated with D/P folate (r = 0.686, P < .001). In subgroup analysis, neither the plasma folate level nor the D/P folate significantly differed between men and women.

CONCLUSIONS

Our study provides clinical evidence that the PET grade is associated with the plasma folate level and D/P folate, regardless of sex. Larger cohort studies are warranted to assess the importance of folate supplementation during PD based on PET grades.

Construction and validation of a predictive model for the risk of peritoneal dialysis-associated peritonitis after peritoneal dialysis catheterization

Aim

To construct and validate a risk prediction model for the development of peritoneal dialysis-associated peritonitis (PDAP) in patients undergoing peritoneal dialysis (PD).

Methods

This retrospective analysis included patients undergoing PD at the Department of Nephrology, the First Affiliated Hospital of Anhui University of Chinese Medicine, between January 2016 and January 2021. Baseline data were collected. The primary study endpoint was PDAP occurrence. Patients were divided into a training cohort (n = 264) and a validation cohort (n = 112) for model building and validation. Least Absolute Shrinkage and Selection Operator (LASSO) regression was applied to optimize the screening variables. Predictive models were developed using multifactorial logistic regression analysis with column line plots. Receiver operating characteristic (ROC) curves, calibration curves, and Hosmer-Lemeshow goodness-of-fit tests were used to verify and evaluate the discrimination and calibration of the prediction models. Decision curve analysis (DCA) was used to assess the clinical validity of the prediction models.

Results

Five potential predictors of PDAP after PD catheterization were screened using LASSO regression analysis, including neutrophil-to-lymphocyte ratio (NLR), serum ALBumin (ALB), uric acid (UA), high sensitivity C-reactive protein (hsCRP), and diabetes mellitus (DM). Predictive models were developed by multi-factor logistic regression analysis and plotted in columns. The area under the ROC curve (AUC) values were 0.891 (95% confidence interval [CI]: 0.829-0.844) and 0.882 (95% CI: 0.722-0.957) for the training and validation cohorts, respectively. The Hosmer-Lemeshow test showed a good fit (p = 0.829 for the training cohort; p = 0.602 for the validation cohort). The DCA curves indicated that the threshold probabilities for the training and validation cohorts were 4-64% and 3-90%, respectively, predicting a good net gain for the clinical model.

Conclusion

NLR, ALB, UA, hsCRP, and DM are independent predictors of PDAP after PD catheterization. The column line graph model constructed based on the abovementioned factors has good discriminatory and calibrating ability and helps to predict the risk of PDAP after PD catheterization.

High Serum Uric Acid and High-Sensitivity C Reactive Protein Concentrations Predict Three-Year Cardiovascular Mortality in Patients Treated With Continuous Ambulatory Peritoneal Dialysis

AIMS

This study aims to access the predicting value of serum uric acid (UA) and high-sensitivity C reactive protein (hs-CRP) concentration on three-year cardiovascular-related mortality in patients performing continuous ambulatory peritoneal dialysis (CAPD).

METHODS

A total of267 CAPD patients [150 male (56.2%); mean age 48.93 ± 13.58 years] were included in our study. All patients had measured serum UA and hs-CRP concentration. A high-sensitivity particle-enhanced immunoturbidimetric assay determined serum hs-CRP; serum UA levels were determined using an enzymatic colorimetric assay. All patients were followed for three years to detect cardiovascular-related mortality by cardiologists and stroke specialists.

RESULTS

Mean serum UA level was 415.16 ± 84.28 µmol/L, 58.4% of patients had increased serum UA level. Median serum hs-CRP level was 2 (1-4) mg/L, 12.4% of patients had increased serum hs-CRP level. During 36 months of follow-up, 41 patients (15.4%) had cardiovascular-related mortality. The results of Cox proportional hazards regression showed that hypertension, diabetes, high serum UA and hs-CRP were risk factors that related to cardiovascular-related mortality (p<0.05). The receiver operating characteristic (ROC) curve and Kaplan-Meier analysis results showed that UA and hs-CRP level had predictive value for three-year cardiovascular-related mortality in CAPD patients [uric acid: area under the curve (AUC)=0.822; hs-CRP: AUC=0.834, p < 0.001].

CONCLUSION

High serum UA and hs-CRP levels were predictive factors of cardiovascular-related mortality in CAPD patients.