Clinical significance of serum urea-to-creatinine ratio in patients undergoing peritoneal dialysis

INTRODUCTION

We aimed to determine the correlation between the serum urea-to-creatinine ratio and residual kidney function (RKF) in patients undergoing peritoneal dialysis (PD), as well as its predictive value for PD-related outcomes.

METHODS

This study included a cross-sectional study to assess the correlation between serum urea-to-creatinine ratio and RKF in 50 patients on PD and a retrospective cohort study to assess the association between serum urea-to-creatinine ratio and PD-related outcomes in 122 patients who initiated PD.

RESULTS

Serum urea-to-creatinine ratios had significant positive correlations with renal Kt/V and creatinine clearance values (r = 0.60, p < 0.001 and r = 0.61, p < 0.001, respectively). Additionally, serum urea-to-creatinine ratio was significantly associated with a lower risk of transfer to hemodialysis or PD/hemodialysis hybrid therapy (hazard ratio: 0.84, 95% confidence interval: 0.75-0.95).

CONCLUSION

The serum urea-to-creatinine ratio can be an indicator of RKF and a prognostic factor in patients undergoing PD.

High body mass index is a risk factor for transition to hemodialysis or hybrid therapy and peritoneal dialysis-related infection in Japanese patients undergoing peritoneal dialysis

PURPOSE

Obesity may negatively impact the clinical outcomes of patients undergoing peritoneal dialysis (PD). However, the impact of obesity on PD-related outcomes remains unclear. We herein examined the association of high body mass index (BMI) with complete hemodialysis (HD) transfer, transition to HD and PD/HD hybrid therapy, peritonitis, catheter exit-site and tunnel infection (ESI/TI), and heart failure-related hospitalization.

METHODS

This retrospective cohort study included 120 patients who underwent PD-catheter insertion between January 2008 and June 2018. BMI ≥ 25 kg/m² at the time of PD-catheter insertion was defined as high BMI, and its association with outcomes was analyzed using the log-rank test and Cox proportional hazards models.

RESULTS

The follow-up duration was 46.2 (23.3-75.3) months. The time until transfer to HD and hybrid therapy was significantly shorter in the high BMI group than that in the low BMI group, whereas the time until HD transfer was not significantly different between the two groups (P < 0.001 and 0.18, respectively). Peritonitis-free and ESI/TI-free survivals were significantly shorter in the high BMI group than those in the low BMI group (P = 0.006 and 0.03, respectively). After adjusting for age, sex, diabetes mellitus, and estimated glomerular filtration rate, high BMI remained a significant risk factor for transferring to HD and hybrid therapy, peritonitis, and ESI/TI (hazard ratio [HR] 2.60, P < 0.001; HR 2.08, P = 0.01; HR 2.64, P = 0.02, respectively).

CONCLUSION

BMI ≥ 25 kg/m² is a risk factor for transition to HD and hybrid therapy, peritonitis, and ESI/TI, but not for complete HD transfer in Japanese patients with PD.

Effects of exercise on residual renal function in patients undergoing peritoneal dialysis: A post-hoc analysis of a randomized controlled trial

We aimed to investigate the effects of exercise on renal outcomes in patients undergoing peritoneal dialysis (PD). In a post-hoc analysis of a randomized controlled trial of a 12-week home-based exercise program involving 47 patients undergoing PD, we excluded 18 patients with anuria and analyzed 13 and 16 patients in the usual care and exercise groups, respectively. The primary outcomes were weekly renal creatinine clearance (CCr) and urinary biomarkers: liver-type fatty acid-binding protein (L-FABP) and the microalbumin-to-creatinine ratio (ACR). Although the maintenance of weekly renal CCr in the exercise group was not significantly different compared with that in the usual care group (P = .09), urinary L-FABP levels (P = .02) and ACR (P = .04) were significantly decreased in the exercise group. To the best of our knowledge, this is the first study to demonstrate the beneficial effects of exercise on renal outcomes in patients undergoing PD.

Inflammatory markers as mortality predictors in continuous ambulatory peritoneal dialysis patients

BACKGROUND/AIM

Besides peritonitis, the most common complication, indicators of chronic inflammation are also present in patients treated by peritoneal dialysis. The aim of this study was to analyze the predictive value of inflammatory parameters on mortality of continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

Eighty-seven patients (57 males), aged from 30 to 85 [62.92 (10.61)] years who had been treated by a chronic program of CAPD for 3-113 months were analyzed. The basal period lasted 3 months with a follow-up of 30 months. Clinical parameters, dialysis adequacy and laboratory parameters including some inflammatory markers: serum amyloid-A (SAA), high sensitive C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and leukocytes were determined for each patient. Cox regression analysis selected the parameters of univariate and multivariate survival analysis.

RESULTS

During the follow-up period, 37 patients (42.5%) died. Univariate analysis selected the following potential mortality predictors (p<0.10): age, months on CAPD, residual urine output, presence of cerebrovascular insult (CVI), KT/V, serum urea and albumin concentrations, SAA, hs-CRP, fibrinogen and ESR. In the multivariate survival analysis four models were created, each with a single inflammatory parameter. In all of these models, besides the age and CVI, inflammatory parameters were the most significant mortality predictors. When the inflammatory markers were analyzed altogether, multivariate analysis established that independent mortality predictors in this group of patients were: SAA, age and CVI.

CONCLUSION

It may be concluded that in this studied group treated by CAPD, SAA was the most significant independent mortality predictor among the analyzed inflammatory markers.

Prognostic value of serum von Willebrand factor, but not soluble ICAM and VCAM, for mortality and cardiovascular events is independent of residual renal function in peritoneal dialysis patients

OBJECTIVE

We explored associations between markers of endothelial dysfunction and outcome events, and whether those associations were independent of residual renal function (RRF) in patients on peritoneal dialysis.

METHODS

The study enrolled 261 incident patients and 68 healthy control subjects who were followed till death, censoring, or study end. Demographics, biochemistry, markers of inflammation (C-reactive protein) and endothelial dysfunction [soluble intercellular adhesion molecule 1 (sICAM), soluble vascular adhesion molecule 1 (sVCAM), and von Willebrand factor (vWf)] were examined at baseline. Outcome events included all-cause death and fatal and nonfatal cardiovascular (CV) events.

RESULTS

Mean levels of vWf, sICAM, and sVCAM were significantly higher in patients than in healthy control subjects. Levels of sICAM and sVCAM, but not vWf, were significantly correlated with RRF. Levels of sICAM and vWf both predicted all-cause mortality and fatal and nonfatal CV events after adjustment for recognizable CV risk factors. The association between sICAM and outcome events disappeared after further adjustment for RRF. However, RRF did not change the predictive role of vWf for outcome events. Compared with the lowest vWf quartile (6.6% - 73.9%), the highest vWf quartile (240.9% - 1161%) predicted the highest risk for fatal and nonfatal CV events (adjusted hazard ratio: 2.05; 95% confidence interval: 1.15 to 3.64; p = 0.014). We observed no associations between sVCAM and RRF, or sVCAM and any outcome event.

CONCLUSIONS

The prognostic value of vWf, but not sICAM, is independent of RRF in predicting mortality and CV events.

The mini-PET in pediatric peritoneal dialysis: a useful tool to predict volume overload?

BACKGROUND

Cardiovascular disease (CVD) in patients on chronic peritoneal dialysis (PD) is a major cause of death and is closely linked to hypertension and volume overload. The mini-Pet has been proposed as a useful tool to evaluate free-water transport (FWT) and characterize ultrafiltration across the peritoneum. Knowledge regarding FWT could be of great value to predict volume overload in PD patients. Our objective in this study was to characterize FWT through the peritoneum in children on PD.

METHODS

We studied clinically stable patients with >2 months on PD. Exclusion criteria were a peritonitis episode up to 2 months prior to entrance into the study and active nephrotic syndrome. A 1-h mini-peritoneal equilibration test (mini-PET) was performed with 3.86 % glucose. Calculations (see text for full definitions) were: Dip Na (Na dial min60 - Na dial min1), Dip D/PNa (D/PNa60 - D/PNa1), total Na removal (NaR = total Na dial60 - Na dial1), ultrafiltration small pores [(UFSP = NaR × 1,000)/Nap], and FWT (UF-UFSP). Peritoneal equilibration test (PET), left ventricular mass index (LVMI, g/m(2)), daily UF, and residual renal function were evaluated. Pearson's correlation coefficient was used to establish correlation between variables.

RESULTS

Sixteen patients were included, with a mean age of 11.8 ± 3.8 years. Free water transport normalized to body surface area (BSA) (FWTn) was 133.9 ± 85.7 ml/m(2); creatinine dialysate-to-plasma (D/P) and glucose dialysate at X dwell time-to-0 dwell time (Dx/D0) ratios were 0.38 ± 0.1 and 0.65 ± 0.09, respectively. LVMI was 46.6 ± 14.8 g/m(2); 2-h creatinine D/P and glucose Dx/D0 showed no correlation with FWTn, UF, and LVMI. FWTn showed a significant inverse correlation with LVMI (r 0.58, p 0.02).

CONCLUSIONS

This study characterized FWT in PD children through the mini-PET. Left ventricular hypertrophy showed a high prevalence in this group, and a significant correlation between LVMI and FWT was found. FWT could be a useful tool to evaluate UF in PD children.

Association of overtime urine volume and ultrafiltration changes with patient survival in continuous ambulatory peritoneal dialysis patients

BACKGROUND

Associations between patient survival and baseline urine volume (UV), ultrafiltration (UF) volume, and combined UV and UF were evaluated in Iranian continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

From 1995 to 2006, data on 1472 CAPD patients from 26 centers were collected. Demographic, clinical, and laboratory characteristics were analyzed using STATA software. Baseline UV was considered as an indicator of residual renal function and patients with an annual decrease of more than 250 cc/day were placed in decreasing UV group. The role of a new variable, net positive fluid removal, which defines as the combination of baseline UV and UF, was also evaluated.

RESULTS

Patients with higher baseline UV were significantly more married and educated and candidate for CAPD based on positive selection criteria. In dichotomous categorization, mean of serum creatinine was lower and albumin was higher in patients with UV ≥ 1000 cc/day compared with UV < 250 cc/day. A significant correlation was found between baseline UV <250 cc/day and ≥1000 cc/day and patient survival. Patients with stable UV had better survival compared with patients with decreasing UV (p = 0.04). There was no correlation between UF and patient survival. Remarkable association with patient and technique survival and net positive fluid removal ≥2000 cc/day and <500 cc/day was observed. Multiple Cox regression analysis revealed significant correlation between net positive fluid removal ≥2000 cc/day and higher patient survival [p = 0.01, hazard ratio (HR) = 13.2], higher first albumin (albumin ≥ 3.5 mg/dL, p = 0.01, HR = 0.02), and lower negative selection (p = 0.0001, HR = 11.8).

CONCLUSION

Loss of UV over time and lower net positive fluid removal increase mortality of PD patients.

Future options for the management of chronic kidney disease in Nigeria

The lack of health care infrastructure and prevalence of infectious disease in Nigeria exacerbate the growing problem of diagnosing and treating chronic kidney disease. Nigeria should place more emphasis on chronic kidney disease education, screening, and prevention; propagation of acceptance of peritoneal dialysis over hemodialysis; subsidization of renal replacement costs; and advancement of the national renal transplantation program.

Protective measures against ultrafiltration failure in peritoneal dialysis patients

Ultrafiltration failure in patients undergoing peritoneal dialysis is a condition with an incidence that increases over time. It is related to increased cardiovascular morbidity and mortality and is a major cause of the abandonment of the treatment technique. Because the number of patients undergoing renal replacement therapy is increasing with society aging and because approximately 10% of this population is treated with peritoneal dialysis, this matter is becoming more common in everyday practice for clinicians involved in the care of patients with chronic renal failure. In this review, we summarize the available measures used to prevent and treat ultrafiltration failure and the current state of research in the field, both in the experimental and clinical settings, focusing on the possible clinical applications of recent findings.

Comparison of icodextrin and glucose solutions for long dwell exchange in peritoneal dialysis: a meta-analysis of randomized controlled trials

BACKGROUND

Icodextrin is widely used in peritoneal dialysis (PD); however, the safety and efficacy of icodextrin are unclear. In the present study, we performed a systematic review of randomized controlled trials (RCTs) that compared icodextrin and glucose for the once-daily long dwell in PD.

METHODS

Electronic searches were performed in MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials to select all eligible studies. Eligible studies, as determined by consensus using predefined criteria, were reviewed, and data were extracted onto a standard form.

RESULTS

In the 9 RCTs that were identified, patients using icodextrin were found to have much greater net ultrafiltration (UF) and a lower incidence of negative net UF compared to patients using 1.5%, 2.5%, and 4.25% glucose solutions. Additionally, icodextrin has a markedly increased UF efficiency ratio and peritoneal clearance of creatinine and urea nitrogen, but residual renal function was not different from patients using glucose solutions for PD. No significant differences were observed between icodextrin and glucose groups with respect to risk of mortality, peritonitis, and total adverse events. Although rashes occurred significantly more often in icodextrin groups, few differences were noted between icodextrin and glucose groups when withdrawal rates secondary to adverse events were compared.

CONCLUSIONS

This meta-analysis suggests that icodextrin provides patients with greater fluid removal and small solute clearance and does not cause any damage to residual renal function. Icodextrin is particularly appropriate for use in patients with high peritoneal transport status.

Low-GDP fluid (Gambrosol trio) attenuates decline of residual renal function in PD patients: a prospective randomized study

BACKGROUND

Residual renal function (RRF) impacts outcome of peritoneal dialysis (PD) patients. Some PD fluids contain glucose degradation products (GDPs) which have been shown to affect cell systems and tissues. They may also act as precursors of advanced glycosylation endproducts (AGEs) both locally and systemically, potentially inflicting damage to the kidney as the major organ for AGE elimination. We conducted a clinical study in PD patients to see if the content of GDP in the PD fluid has any influence on the decline of the residual renal function.

METHODS

In a multicentre approach, 80 patients (GFF > or = 3 mL/min/1.732 or creatinine clearance > or =3 mL/min/1.73 m(2)) were randomized to treatment with a PD fluid containing low levels of GDP or standard PD fluid for 18 months. RRF was assessed every 4-6 weeks. Fluid balance, mesothelial cell mass marker CA125, peritoneal membrane characteristics, C-reactive protein (CRP), total protein, albumin, electrolytes and phosphate were measured repeatedly.

RESULTS

Data from 69 patients revealed a significant difference in monthly RRF change: -1.5% (95% CI = -3.07% to +0.03%) with low GDP (43 patients) vs -4.3% (95% CI = -6.8% to -2.06%) with standard fluids (26 patients) (P = 0.0437), independent of angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker medication. Twenty-four-hour urine volume declined more slowly with low-GDP fluid compared to standard fluids (12 vs 38 mL/month, P = 0.0241), and monthly change of phosphate level was smaller (+0.013 vs +0.061 mg/dL, P = 0.0381).

CONCLUSIONS

Our prospective study demonstrates for the first time a significant benefit concerning preservation of RRF and urine volume of using a PD fluid with low GDP levels. These findings suggest that GDPs might affect patient outcome related to RRF.