Baseline Residual Renal Function Research Articles

#2752 Decline of residual renal function in peritoneal patients: in search of the lost kidney?

Abstract Background and Aims The latest (2020) recommendations of the International Society of Peritoneal Dialysis have proposed a new paradigm of adequacy. In this context, preserving residual renal function (RRF) is considered one of the most important therapeutic targets to reduce cardiovascular risk and mortality. Incremental peritoneal dialysis can contribute to preserving RRF. The goal of this study is to evaluate factors which are associated with a decline in RRF in APD patients. Method We conducted a retrospective study of incidental peritoneal dialysis patients between 2020 and 2022. We started considering 62 patients who underwent APD. 23 were excluded due to lack of data, follow-up of less than 1 year, need for haemodialysis sessions before or during follow-up, interfering surgery (bariatric surgery and nephrectomy) and treatment using the CAPD technique. We analyzed data from 39 APD patients (see Table 1) and classified them into two groups based on their RRF decline using the cut-off of 1 ml/min/year (calculated as the mean of urea and creatinine clearance). They were distinguished into slow progressors and fast progressors and we identified any differences in clinical and dialysis parameters at baseline and 12-month follow-up. We calculated dialytic, renal and total Kt/V in both groups and looked for possible predictors of faster RRF loss. For statistical analysis, we used ANOVA for continuous variables, Kruskal-Wallis for non-continuous variables and Fisher for qualitative variables. Finally, predictive data were extracted using logistic regression. Results We found 22 slow progressors and 17 fast progressors. A significant difference was found in the prevalence of cardiovascular disease (18.2% vs 47.1%, p 0.028), residual renal function (5.71 ml/min vs 6.85 ml/min, p 0,03) and dialysing solution volumes (13.2 L vs 14.1 L, p 0.05) between the two groups, with higher values in the fast progressors. In this group, more male patients were also observed (p 0.11), treated with 2 or more antihypertensive drugs (p 0.30) and exposed to higher weekly dialysate glucose (p 0.23) and daily ultrafiltration rates (p 0.23). At the 12-month follow-up, the mean decline in renal function was -1, 56 ml/min in the entire sample, -3.03 ml/min in the fast progressors group and -0.43 ml/min in the slow progressors group; the change in daily Uf inversely correlated with the change in RRF (p 0.025; r -0.35, Fig. 1). There was a mean reduction in ultrafiltrate volume (-22.7 ml vs +123.5 ml, p 0.028) and in the amount of glucose in the dialysing solutions (-138.6 g vs +100.5 g, p 0.007) compared to baseline values in patients who preserved RRF. In contrast, the difference between the two groups in the number of patients who started PD with<5 sessions per week is borderline (p 0.099). Weekly dialysis Kt/V is higher in fast-progressor patients (1 vs 0.88; p 0.205) with a total weekly Kt/V in both cases above the recommended target of 1.7. On multivariate regression analysis, baseline renal function and the presence of heart disease correlate with a more rapid decline in RRF (p 0.047; p 0.021 respectively). Conclusion With the limitations of low sample size and short follow-up time, we observed that ultrafiltration and peritoneal exposure to dialysate glucose may play a role in RRF loss, but more research is needed to confirm this. We found that patients with heart disease and higher baseline RRF were more likely to experience a faster decline in RRF. Overall findings suggest that maintaining RRF is crucial in APD patients, and incremental dialysis can help preserve it. We recommend further studies with longer follow-up times to better understand the relationship between RRF and APD.

A Fast Decline of Residual Renal Function in the First Year is a Predictor for Early Withdrawal from Peritoneal Dialysis in Non-Diabetic Patients

Background/Aims: Little is known about the relationship between residual renal function (RRF) decline in early period and survival in non-diabetic peritoneal dialysis (PD) patients. Methods: A total of 567 non-diabetic patients who began PD from January 1, 2005 to June 30, 2013 was investigated. The rate of RRF decline was determined by the “slope of the trend equation” of serial RRFs. A composite end-point of all-cause mortality and conversion to hemodialysis (HD) was used, survival status was censored on June 30, 2016. Results: The median of “the slope of RRF decline equation” was 0.308 (0.001-2.111) ml/min/1.73 m2/ month. In the median follow-up period of 43 months (range 12 to 120 months), 65 (11.5%) patients died, 90 (15.9%) patients converted to HD and 171 (30.2%) patients received kidney transplantation. Multivariate linear regression showed male, high baseline RRF, high baseline peritoneal Kt/V urea, low serum albumin and low uric acid were independently associated with the rate of RRF decline in the first year of PD. Multivariate Cox models revealed that RRF decline in the first year remained a predictor for composite end-point (HR, 2.74, 95% CI, 1.53 to 4.90, P=0.001). The patients were divided into high RRF decline group (> 0.308ml/ min/1.73m2/month) and low RRF decline group (≤0.308 ml/min/1.73m2/month). In the first three years of PD, the rate of end-point events was higher in high RRF decline group (23.2%) than that in low RRF decline group (11.0%) (P< 0.001). There were 189 patients in low RRF decline group and 171 patients in high RRF decline group maintaining PD for more than 3 years, in a median follow-up of 54 months (range 37 to 120 months), the survival rate was 30.9% in high RRF decline group and 46.4% in low RRF decline group (P=0.883). In high RRF decline group, there were 92 patients reaching composited end-point and 112 patients maintaining PD; multivariate Cox model showed high peritoneal Kt/V urea after 1 year of PD and high albumin level were protective factors (HR, 0.29, 95% CI, 0.13 to 0.61, P= 0.001; HR, 0.94, 95% CI, 0.90-0.99, P=0.022, respectively), while fast RRF decline remained risk factor for composite end-point (HR, 3.28, 95% CI,1.48-7.31, P=0.004). Conclusion: A faster RRF decline in the first year was a predictor for all-cause mortality and conversion to HD in non-diabetic PD patients, mainly in the first three year. For patients with faster RRF decline, increasing PD dose was effective to improve survival.

Does Residual Renal Function Have a Beneficial Effect on Patient and Technique Survival in Peritoneal Dialysis Patients?

Objectives:Residual renal function (RRF) at the initiation of peritoneal dialysis (PD) therapy can be a predictor of survival in stable PD patients. The aim of the present study was to investigate PD patients regarding the effect of baseline RRF on patient and technique survival.Methods:Urine output at the beginning of PD therapy was evaluated retrospectively in 202 PD patients. Patients were divided into two groups: patients with anuria (urine output ≤100 ml/day) and patients without anuria (urine output >100 ml/day).Results:The number of patients with anuria was 58 in which 38 patients were females. The mean age of the patients was 42.8±14.9 years. The mean follow-up period was 44.2±35 months. Twelve percent of patients with anuria had history of hemodialysis (HD).One hundred forty-four had no anuria (68 females, mean age 43.7±14.5 years, mean follow-up period 39.6±26.1 months, mean urine volume 592±442 ml). Twenty-three patients had received HD therapy before. Sixty-five had anuria in the following 22.5±19.6 months.At the beginning of therapy, systolic and diastolic blood pressures were lower in patients with oliguria than in patients without oliguria (p<0.001), but C-reactive protein (p=0.004) and ferritin (p<0.001) levels were higher. There was no difference between two groups regarding the other parameters (age, follow-up periods, presence of diabetes, ultrafiltration volumes, albumin, hemoglobin, calcium phosphorus product, parathormone, and Kt/V levels) (p>0.05).The peritonitis rate was one episode per 28.2 versus 30 patient-months for the anuric and non-anuric groups, respectively (p>0.05).For Kaplan–Meier survival analysis, the mean technique survival rates at 1 and 3 years were 97% and 86.6% in patients without anuria and 94% and 85.3% in patients with anuria, respectively. The 5-year technique survival rates according to residual volume states were not statistically significant with log-rank test (p>0.05).The 1-, 3-, and 5-year survival rates were 96.9%, 89.6%, and 86.5% in patients without anuria, respectively, whereas they were 87.3%, 77.3%, and 53.7% in patients with anuria, respectively. The 5-year survival rates according to residual volume states were statistically significant (p<0.05).Conclusion:RRF at the beginning of PD has an important and positive impact on patient survival in PD patients. Peritonitis rates and technique survival were not different for patients with anuria and without anuria.

Rapid Change in Residual Renal Function Decline Is Associated with Lower Survival and Worse Residual Renal Function Preservation in Peritoneal Dialysis Patients.

The survival advantage observed among peritoneal dialysis patients early on after dialysis initiation has been largely attributed to residual renal function (RRF) preservation due to higher baseline residual function and fewer comorbidities. We hypothesize that a rapid decline in RRF is associated with higher risk of anuria and mortality. In a retrospective cohort study of 581 subjects on peritoneal dialysis with longitudinal prevalent data, we assessed whether RRF change over time, in addition to baseline RRF, increased risk of mortality and anuria using Kaplan-Meier analysis and Cox proportional hazard analysis to control for known risk factors. Rapid RRF decline (≥ 0.09 decline) over a 12-month period was associated with a 2.6-fold increase in the risk of death (hazard ratio [HR] 2.60, 95% confidence interval [CI] 1.66 - 4.07, compared with < 0.09 decline) and a 2-fold increase in anuria (HR 2.06, 95% CI 1.24 - 3.42). Each quartile of increasing severity of RRF decline over a 12-month period increased risk incrementally for death (2nd quartile: HR 3.04, CI 1.26 - 7.34; 3rd quartile: HR 4.01, CI 1.71 - 9.83; 4th quartile HR 5.78, CI 2.10 - 15.9) and generally for anuria (quartiles with HR 5.72 - 7.21). The escalating risk of mortality and anuria was greater for those with diabetes mellitus. In conclusion, rapid decline in RRF over a 12-month period increased the risk of mortality and likewise anuria, beyond previously established risk factors for mortality and anuria. The impact on mortality and RRF preservation was particularly severe for those with diabetes mellitus.

Predictors of Residual Renal Function Decline in Peritoneal Dialysis Patients: The balANZ Trial.

♦ OBJECTIVE: Preservation of residual renal function (RRF) is associated with improved survival. The aim of the present study was to identify independent predictors of RRF and urine volume (UV) in incident peritoneal dialysis (PD) patients. ♦ METHODS: The study included incident PD patients who were balANZ trial participants. The primary and secondary outcomes were RRF and UV, respectively. Both outcomes were analyzed using mixed effects linear regression with demographic data in the first model and PD-related parameters included in a second model. ♦ RESULTS: The study included 161 patients (mean age 57.9 ± 14.1 years, 44% female, 33% diabetic, mean follow-up 19.5 ± 6.6 months). Residual renal function declined from 7.5 ± 2.9 mL/min/1.73 m2 at baseline to 3.3 ± 2.8 mL/min/1.73 m2 at 24 months. Better preservation of RRF was independently predicted by male gender, higher baseline RRF, higher time-varying systolic blood pressure (SBP), biocompatible (neutral pH, low glucose degradation product) PD solution, lower peritoneal ultrafiltration (UF) and lower dialysate glucose exposure. In particular, biocompatible solution resulted in 27% better RRF preservation. Each 1 L/day increase in UF was associated with 8% worse RRF preservation (p = 0.007) and each 10 g/day increase in dialysate glucose exposure was associated with 4% worse RRF preservation (p < 0.001). Residual renal function was not independently predicted by body mass index, diabetes mellitus, renin angiotensin system inhibitors, peritoneal solute transport rate, or PD modality. Similar results were observed for UV. ♦ CONCLUSIONS: Common modifiable risk factors which were consistently associated with preserved RRF and residual UV were use of biocompatible PD solutions and achievement of higher SBP, lower peritoneal UF, and lower dialysate glucose exposure over time.

Weight change during the first year of peritoneal dialysis: Risk factors and prognostic implications

BackgroundWeight gain is common amongst patients who start peritoneal dialysis (PD). However, the prevalence, risk factors, and long-term implications of body weight gain in new PD patients have not been explored. MethodsWe studied 444 consecutive new PD patients. Body weight at the time of initiation of PD and 1 year later, and related clinical factors, were reviewed. Patients were followed for 60.9 ± 32.8 months for survival analysis. ResultsThe mean weight change after 1 year of PD was 1.34 ± 3.27 kg; 109 patients (24.6%) had weight gain > 3 kg. Patients without any peritonitis episodes during the 1st year of PD had significantly more weight gain than those who had peritonitis (1.58 ± 3.17 vs. 0.16 ± 3.56 kg, p = 0.001). There were no significant correlations between body weight change and glucose load, peritoneal transport characteristics, dialysis adequacy index, or baseline residual renal function. For patients with weight loss > 0.5 kg, weight change within 0.5 kg, weight gain > 0.5–3.0 kg, and weight gain > 3 kg, the patient survival rates at 60 months were 45.0%, 54.8%, 54.0%, and 52.9%, respectively (p = 0.213), while technique survival were 28.1%, 40.3%, 40.8%, and 36.7%, respectively (p = 0.03). ConclusionWeight gain is common among Chinese patients during the 1st year of PD but is not associated with any adverse clinical outcome. In contrast, weight loss during the 1st year of PD is common amongst PD patients who have peritonitis, and is associated with worse technique survival subsequently.

Circulating bacterial-derived DNA fragment level is a strong predictor of cardiovascular disease in peritoneal dialysis patients.

BackgroundCirculating bacterial DNA fragment is related to systemic inflammatory state in peritoneal dialysis (PD) patients. We hypothesize that plasma bacterial DNA level predicts cardiovascular events in new PD patients.MethodsWe measured plasma bacterial DNA level in 191 new PD patients, who were then followed for at least a year for the development of cardiovascular event, hospitalization, and patient survival.ResultsThe average age was 59.3 ± 11.8 years; plasma bacterial DNA level 34.9 ± 1.5 cycles; average follow up 23.2 ± 9.7 months. At 24 months, the event-free survival was 86.1%, 69.8%, 55.4% and 30.8% for plasma bacterial DNA level quartiles I, II, III and IV, respectively (p < 0.0001). After adjusting for confounders, plasma bacterial DNA level, baseline residual renal function and malnutrition-inflammation score were independent predictors of composite cardiovascular end-point; each doubling in plasma bacterial DNA level confers a 26.9% (95% confidence interval, 13.0 – 42.5%) excess in risk. Plasma bacterial DNA also correlated with the number of hospital admission (r = -0.379, p < 0.0001) and duration of hospitalization for cardiovascular reasons (r = -0.386, p < 0.0001). Plasma bacterial DNA level did not correlate with baseline arterial pulse wave velocity (PWV), but with the change in carotid-radial PWV in one year (r = -0.238, p = 0.005).ConclusionsCirculating bacterial DNA fragment level is a strong predictor of cardiovascular event, need of hospitalization, as well as the progressive change in arterial stiffness in new PD patients.

Changes in echocardiographic parameters according to the rate of residual renal function decline in incident peritoneal dialysis patients.

Residual renal function (RRF) is associated with left ventricular (LV) hypertrophy as well as all-cause and cardiovascular (CV) mortality in patients with end-stage renal disease. However, no studies have yet examined the serial changes in echocardiographic findings according to the rate of RRF decline in incident dialysis patients. A total of 81 patients who started peritoneal dialysis (PD) between 2005 and 2012 at Yonsei University Health System, Seoul, South Korea, and who underwent baseline and follow-up echocardiography within the first year of PD were recruited. Patients were dichotomized into "faster" and "slower" RRF decline groups according to the median values of RRF decline slope (-1.60 mL/min/y/1.73 m(2)). Baseline RRF and echocardiographic parameters were comparable between the 2 groups. During the first year of PD, there were no significant changes in LV end-diastolic volume index (LVEDVI), left atrial volume index (LAVI), or LV mass index (LVMI) in the "faster" RRT decline group, while these indices decreased in the "slower" RRT decline group. The rate of RRF decline was a significant determinant of 1-year changes in LVEDVI, LAVI, and LVMI. The linear mixed model further confirmed that there were significant differences in the changes in LVEDVI, LAVI, and LVMI between the 2 groups (P = 0.047, 0.048, and 0.001, respectively). During a mean follow-up duration of 31.9 months, 4 (4.9%) patients died. Compared with the "slower" RRF decline group, CV composite (20.29/100 vs 7.18/100 patient-years [PY], P = 0.098), technique failure (18.80/100 vs 4.19/100 PY, P = 0.006), and PD peritonitis (15.73/100 vs 4.95/100 PY, P = 0.064) developed more frequently in patients with "faster" RRF decline rate. On multivariate Cox regression analysis, patients with "faster" RRF decline rate showed 4.82-, 4.44-, and 7.37-fold higher risks, respectively, for each clinical outcome. Preservation of RRF is important for conserving cardiac performance, resulting in an improvement in clinical outcomes of incident PD patients.

Relation of ankle‐brachial index to the rate of decline of residual renal function in peritoneal dialysis patients

The aim of this study was to determine whether ankle-brachial index (ABI) predicts the rate of decline of residual renal function (RRF) in peritoneal dialysis (PD) patients. Previous studies demonstrated the importance of loss of RRF in predicting all-cause risk and cardiovascular mortality in PD patients. It is also known that patients with a low ABI value have a greater risk for deteriorating renal function in the general population. The relationship between ABI and the declining rate of RRF in PD patients with an additional dialysis-specific risk factor is uncertain. Seventy-four PD patients with RRF of more than 1 mL/min per 1.73 m(2) were analyzed. ABI was used as the surrogate measure of pre-existing cardiovascular disease and atherosclerosis burden to further determine the outcome of RRF in this study. The slope of decline of RRF was used to determine the outcome. Based on the multivariate analysis, only ABI (P < 0.001), diabetes (P = 0.02) and baseline RRF (P = 0.009) independently predicted a faster decline in RRF. A stepwise multiple linear regression analysis demonstrated that ABI was an independent predictor for the slope of decline of RRF (P < 0.001). A low ABI is an independent predictor of not only the known atherosclerotic events, but also of the rate of decline of RRF over time in PD patients.

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Uric acid is associated with the rate of residual renal function decline in peritoneal dialysis patients

Uric acid (UA) is known to play a pathogenic role in chronic kidney disease (CKD). However, its effect in end-stage renal disease (ESRD) has not yet been elucidated. We explored the prevalence of hyperuricaemia and the relationship between UA and residual renal function (RRF) in peritoneal dialysis (PD) patients. The subjects of this study were 134 PD patients who started dialysis at the Yonsei University Health System between January 2000 and December 2005. Timed urine collections were performed within 1 month of PD commencement and at 6-month intervals thereafter. The slope of decline of RRF over time was calculated by linear regression analysis of serial urinary urea and creatinine clearances for each patient. Biochemical and clinical data at the time of initial urine collection were considered as baseline. At baseline, 32.8% of the PD patients had hyperuricaemia (UA >or=7.0 mg/dl). A significant majority of patients with hyperuricaemia were diabetic (P = 0.02). Hypertensive patients had a higher UA level (P = 0.002) compared to normotensive patients. The overall reduction rate of RRF in hyperuricaemic patients was significantly higher than in the normouricaemic group (P = 0.001). In the multiple linear regression analysis, hyperuricaemia and history of DM showed a significant negative correlation with the reduction rate of RRF after adjusting for demographic data, comorbid conditions, body mass index, baseline RRF and medications (P = 0.001). Hyperuricaemia is common among PD patients and is significantly associated with the rate of decline of RRF.

Rate of decline of residual renal function is associated with all-cause mortality and technique failure in patients on long-term peritoneal dialysis

Residual renal function (RRF) at the initiation of peritoneal dialysis (PD) therapy can predict patient outcome. However, RRF declines with time at variable rates in different patients. This study was performed to compare the impact of baseline RRF and the rate of RRF decline on patient survival and on death-censored technique survival after initiation of long-term PD. We enrolled 270 patients with sufficient urine amount (daily urine volume >100 mL) from a medical centre in North Taiwan who began PD between January 1996 and December 2005 and followed them until December 2007. The study population was stratified by the decline rate of RRF into a fast, intermediate and slow decline group. The Kaplan-Meier survival analysis was used to determine patient survival and technique survival. The Cox regression model was used to identify factors associated with patient outcome. The proportional odds polychotomous logistic regression model was used to identify variables associated with rapid decline of RRF. During an average follow-up period of 45 months, 50 (18.5%) deaths, 67 (24.8%) death-censored technique failures (transfer to haemodialysis) and 43 (15.9%) renal transplantations occurred. The median rate of RRF decline was 0.885 mL/min/1.73 m(2) per year. Survival analysis showed that patients with fast RRF decline had worse survival and increased risk of technique failure. The multivariate Cox regression model confirmed that the rate of RRF decline was an independent factor associated with patient and technique survival and was a more powerful prognostic factor than basal RRF. Variables associated with a rapid decline of RRF were larger body mass index, presence of diabetes, prior history of congestive heart failure, use of diuretics, peritonitis episodes and hypotensive events. Our data indicate that the rate of decline of RRF is a more powerful prognostic factor than baseline RRF associated with all-cause mortality and technique failure in patients on long-term PD. To prevent accelerated loss of RRF, it is imperative that every effort be made to avoid overdiuresis, peritonitis and hypotensive episodes, especially in those with diabetes, obesity and congestive heart failure.

Predictors of Decline of Residual Renal Function in New Peritoneal Dialysis Patients

The aim of this study was to prospectively evaluate the risk factors for decline of residual renal function (RRF) in an incident peritoneal dialysis (PD) population. Prospective observational study of an incident PD cohort at a single center. Tertiary-care institutional dialysis center. The study included 146 consecutive patients commencing PD at the Princess Alexandra Hospital between 1 August 1995 and 1 July 2001 (mean age 54.8 +/- 1.4 years, 42% male, 34% diabetic). Patients with failed renal transplants (n = 26) were excluded. Timed urine collections (n = 642) were performed initially and at 6-month intervals thereafter to measure RRF. The development of anuria was also prospectively recorded. The mean (+/- SD) follow-up period was 20.5 +/- 14.8 months. The median slope of RRF decline was -0.05 mL/minute/month/1.73 m2. Using binary logistic regression, it was shown that the 50% of patients with more rapid RRF loss (< -0.05 mL/min/month/1.73 m2) were more likely to have had a higher initial RRF at commencement of PD [adjusted odds ratio (AOR) 1.83, 95% confidence interval (CI) 1.39-2.40] and a higher baseline dialysate/ plasma creatinine ratio at 4 hours (D/P creat; AOR 44.6, 95% CI 1.05-1900). On multivariate Cox proportional hazards model analysis, time from commencement of PD to development of anuria was independently predicted by baseline RRF [adjusted hazard ratio (HR) 0.81, 95% CI 0.60-0.81], D/P creat (HR 2.87, 95% CI 2.06-82.3), body surface area (HR 6.23, 95% CI 1.53-25.5), dietary protein intake (HR 2.87, 95% CI 1.06-7.78), and diabetes mellitus (HR 1.65, 95% CI 1.00-2.72). Decline of RRF was independent of age, gender, dialysis modality, urgency of initiation of dialysis, smoking, vascular disease, blood pressure, medications (including angiotensin-converting enzyme inhibitors), duration of follow-up, and peritonitis rate. The results of this study suggest that high baseline RRF and high D/P creat ratio are risk factors for rapid loss of RRF. Moreover, a shorter time to the onset of anuria is independently predicted by low baseline RRF, increased body surface area, high dietary protein intake, and diabetes mellitus. Such at-risk patients should be closely monitored for early signs of inadequate dialysis.