Immune Dysfunction in Dialysis Patients—Prevention and Treatment Strategies

Immune dysfunction, resulting in infection or inflammation, or both, is closely associated with poor clinical outcome in end-stage renal disease patients. So far, no single measure can effectively address this condition, because many factors, such as uremia per se and dialysis treatment are involved in the pathogenesis. Our review focuses on currently available treatments and prevention options, and identifies future research needs.

Longitudinal Evaluation of a Weight Reduction Program for Patients on Peritoneal Dialysis

♦ Objectives

Patients on peritoneal dialysis (PD) are exposed to glucose-based dialysate solutions with consequent risk of obesity and its attendant health problems. We wished to examine the role of changes in dialysis prescription, individualized dietary input, and exercise on body weight and composition.

♦ Design

A 1 year, prospective interventional study integrating the care of the renal nurse, dietitian, and physiotherapist to support, educate, and encourage overweight patients on PD in a weight-reduction program.

♦ Patients

Patients were considered for the study if they had been on PD for more than 3 months, had a body mass index (BMI) > 25, and were considered medically fit to undergo the planned exercise program. Recruitment was intentionally limited to a maximum of 12 patients to facilitate group interaction. Weight, BMI, and bioimpedance were measured every 3 months.

♦ Results

8 of 11 enrolled patients completed the study; 3 received transplants. There was a significant fall in median body weight at initiation, from 94.6 kg to 92.4 kg at 6 months and 89.5 kg at 12 months ( p = 0.017). This equates to a reduction in BMI from 33.2 (range 26.6 – 38.4) kg/m2 at initiation to 32.1 (range 24.5 – 37.6) kg/m2 at 6 months and 32.1 (range 23.9 – 36.5) kg/m2 at 12 months. There were no significant changes in total body water, lean body mass, or percentage body fat during the study.

♦ Conclusion

7 of 8 patients achieved significant weight loss during the study. The use of an informal group setting motivated patients to continue with exercise and sensible eating patterns. This study demonstrates that, with adequate support, PD patients can achieve and maintain weight loss.

Chronic Inflammation in Peritoneal Dialysis: The Search for the Holy Grail?

Mortality and morbidity in chronic kidney disease (CKD) patients are unacceptably high. The annual mortality rate due to cardiovascular disease (CVD) is approximately 9%, which, for the middle-aged person, is at least 10- to 20-fold higher than for the general population. Classic risk factors for CVD are highly prevalent in CKD patients, but they cannot fully account for the excessive rate of CVD in this population. Instead, it has become increasingly clear that nontraditional risk factors, such as systemic inflammation, may play a key role in the development of atherosclerosis. It is well established that inflammatory markers are very powerful predictors of high CVD morbidity and mortality not only in the general population, but particularly in CKD patients. Signs of a sustained low-grade inflammation, such as increased levels of C-reactive protein (CRP), are present in the majority of stage 5 CKD patients, even in patients in clinically stable condition, and they are also commonly observed after the initiation of dialysis therapy. Dialysis therapy — hemodialysis as well as peritoneal dialysis (PD) — may itself contribute to systemic inflammation. Local intraperitoneal inflammation can also occur in patients treated with PD. These local effects may result in a low-grade inflammation, caused by the bioincompatibility of conventional glucose-based dialysis fluids, to intense inflammation associated with peritonitis. Given these circumstances, it is reasonable to hypothesize that strategies aiming to reduce inflammation are potentially important and novel, and could serve to reduce CVD, thereby lowering morbidity and mortality in patients with CKD. In this review we provide information supporting the hypothesis that systemic inflammation is tightly linked to the most common complications of CKD patients, in particular those on PD, and that local inflammation in PD may contribute to various related complications. The aims of this review are to discuss the reasons that make inflammation an attractive target for intervention in CKD, the particular aspects of the inflammation–CVD axis during PD treatment that are likely involved, and possible means for the detection and management of chronic inflammation in PD patients.

Prevalence of obesity and obesity-associated muscle wasting in patients on peritoneal dialysis

BACKGROUND AND AIMS

A progressive decrease in muscle mass until full-blown sarcopenia may occur in patients on peritoneal dialysis (PD) and worsen their life quality and expectancy. Here we investigate the prevalence of obesity and obesity-associated muscle wasting in PD patients.

PATIENTS AND METHODS

The study design was observational, cross sectional. Body composition was assessed with BIA and BIVA in 88 PD patients (53.4 ± 13.1 years; 67% male). Patients with obesity and/or with reduced muscle mass were identified using FMI and SM/BW cutoff values, respectively. Inflammatory status was assessed by measuring CRP and fibrinogen blood levels.

RESULTS

A total of 44.3% of the patients showed a reduced muscle mass (37.5% moderate and 6.8% severe). The prevalence of obesity was 6.1%, 81.8%, and 100% in patients with normal, moderately, and severely reduced muscle mass, respectively (p < 0.05). Of the total, 15.2% of the patients with normal muscle mass, 18.4% of those with moderately reduced muscle mass, and 66.7% of those with severely reduced muscle mass had diabetes. The prevalence of severe muscle mass loss was higher in those with diabetes than in those without diabetes (22.2% vs. 2.8%, p < 0.05). Patients with obesity-associated muscle wasting showed higher fibrinogen (613.9 ± 155.1 vs. 512.9 ± 159.5 mg/dL, p < 0.05) and CPR (1.4 ± 1.3 vs. 0.6 ± 0.8 mg/dL, p < 0.05) blood concentrations than those with normal body composition.

CONCLUSION

Obesity and diabetes were strongly associated with muscle mass loss in our PD patients. It remains to be established whether prevention of obesity with nutritional interventions can halt the occurrence of muscle mass loss in patients on PD.

Effects of Excessive Body Fat Accumulation on Long-Term Outcomes During Peritoneal Dialysis

Background:Significant body fat accumulation is an inevitable but potentially serious problem in peritoneal dialysis (PD) patients. Whether excessive fat gain predicts long-term outcomes in these patients remains unknown.Methods:In this prospective cohort study (n = 297), the associations of excessive fat accumulation with patient survival and PD failure rate were examined. Based on dialysis duration at the time of study enrollment, patients were divided into short- (< 2 years) and long-term (> 2 years) groups. Body weight (BW) and body composition were measured twice, 12.8 ± 4.6 months apart. Excessive fat accumulation was defined as a 1-year change in the percentage of body fat (ΔPBF) over the highest quartile (5.0% for men, 5.4% for women).Results:Substantial 1-year increases in BW and PBF were observed only in the short-term group (p < 0.001 and p = 0.027, respectively); changes were insignificant in the long-term group. In the short-term group, the ΔPBF was associated closely with unfavorable baseline metabolic profiles, including old age, diabetes, obesity, elevated blood pressure, and edema. Accordingly, the mortality rate was significantly higher in patients with, than in those without, excessive fat accumulation (hazard ratio [HR] 3.26, 95% confidence interval [CI], 1.05 - 10.26). It also increased the incident risk of PD failure 2.22-fold (95% CI, 1.08 - 4.54), even after adjustment for diabetes, obesity, and fluid status. In the long-term group, fat gain had no impact on long-term prognosis.Conclusions:Excessive fat accumulation during the early period of PD was associated with baseline unhealthy metabolic profiles, a higher mortality rate, and a higher PD failure rate, independent of baseline obesity and fluid status.

Clinical value of body composition monitor to evaluate lean and fat tissue mass in peritoneal dialysis

BACKGROUND/OBJECTIVES

Bioimpedance analysis is often routinely performed in any dialysis unit to guide fluid management but can provide a reproduceable assessment of fat and muscle mass. We wished to determine the clinical significance of low muscle or high fat mass and the determinants that influence their change.

SUBJECTS/METHODS

We performed retrospective analysis of 824 patients on peritoneal dialysis who underwent routine repeated bioimpedance analysis measurements using the body composition monitor (BCM).

RESULTS

Lean tissue index (LTI) was an independent predictor of mortality when sex, age, PD vintage and diabetes status were included in the models (HR 0.93; 95% CI 0.86-1.00, p < 0.05) and when baseline serum albumin was included in a separate model (HR 0.86; 95% CI: 0.79-0.93, p < 0.001). High fat tissue index (FTI) was an independent predictor of mortality when demographic factors were included (HR 0.87; 95% CI: 0.78-0.97, p < 0.02), but not with the addition biochemical parameters. Changes in body composition of 206 patients over a 2-year follow-up period could not be predicted by baseline demographics, functional or biochemical assessments. However, there was a strong inverse relationship between changes in LTI and FTI. There were no associations between changes in body composition with prescribed dialysate glucose.

CONCLUSIONS

We showed body composition changes are common and complex. LTI was an independent predictor of survival. Changes in LTI and FTI could not be predicted by baseline parameters. BCM may be a sensitive and accurate tool to monitor changes in body composition during dialysis treatment.

Waist circumference as a predictor of mortality in peritoneal dialysis patients: a follow-up study of 48 months

Body-fat gain is a common finding among peritoneal dialysis (PD) patients, and the accumulation of adipose tissue occurs predominantly in the abdominal area. Waist circumference (WC) is a reliable marker of abdominal obesity and its association with worse outcomes has been demonstrated in non-dialysis and haemodialysis patients. We aimed at investigating whether WC measurements as well as the changes over time in WC were able to predict mortality in PD patients. This prospective study included 109 patients undergoing PD (57 % male, age 52 (sd 16) years, 32 % diabetics, 48 % BMI≥25 kg/m2). WC was measured at the umbilicus level (empty abdominal cavity), and values >88 cm for women and >102 cm for men were considered high. Nutritional status and laboratory parameters were also evaluated. WC was measured at baseline and after 6 months, and mortality was registered during a period of 48 months. High WC was observed in 55 % of women and in 23 % of men at baseline. After 6 months, 61 % of the patients showed an increased WC. At the end of the study, twenty-seven deaths were registered. A significant increase in WC was observed only in the non-survivor group. In the Cox regression analysis adjusting for sex, age, duration on dialysis, diabetes, BMI, serum albumin and C-reactive protein, high WC at baseline as well as the 6-month increase in WC were independently associated with mortality. This study demonstrated that a high WC and the increase over time in WC were both predictors of mortality in PD patients.

Excessive Weight Gain during the First Year of Peritoneal Dialysis Is Associated with Inflammation, Diabetes Mellitus, and a Rapid Decrease in Residual Renal Function

OBJECTIVES

Significant weight gain is a potential problem in most patients starting peritoneal dialysis (PD); however, few studies have explored the clinical effects of increased body weight (BW) in these patients. We evaluated the effect of excess weight gain during the first year after PD on residual renal function (RRF).

METHODS

A total of 148 incident PD patients were analyzed in a longitudinal observational study. The mean duration of follow-up was 23.8 months. RRF was measured at baseline (within 1 month of starting PD) and thereafter at 6-month intervals for 2-3 years or until loss of RRF. BW was measured at the time of RRF measurement, and excess weight gain was defined as a BW increase over the median value (3.0%).

RESULTS

The median 1-year increase in BW was 2.3kg (IQR, 1.01-4.58) or 3.0% (IQR, 1.13-5.31). The mean slope of RRF decline was -0.068 ± 0.053 mL/min/month/1.73m2, and RRF loss developed in 48 patients at a mean follow-up time of 19.4 ± 6.8 months. Patients with BW increases > 3.0% showed significantly increased RRF decline rate compared to those without excess weight gain (p<0.001), and the BW increase (%/year) correlated significantly with higher hs-CRP levels and RRF decline rate. High systolic blood pressure, diabetes, large amount of proteinuria and excess BW gain significantly influenced the RRF decline rate. Also, it increased the risk of RRF loss by 4.17-fold (95% confidence intervals, 1.87-9.28; p<0.001).

CONCLUSIONS

Excess weight gain during the first year of PD was closely linked to systemic inflammation, diabetes and rapid decline in RRF.

Obesity in patients undergoing dialysis and kidney transplantation

Obesity poses a major challenge for nephrologists and patients alike, and its prevalence among patients with kidney disease is increasing at least as fast as in the general population. Although the body mass index (BMI) is the most commonly used measurement of excess adiposity, it has important limitations that can be ameliorated by incorporating other markers of body composition. The influence of obesity on outcomes in patients undergoing dialysis and kidney transplantation is of great interest. Although the preponderance of epidemiologic data suggests that, at least in patients undergoing dialysis, obesity has a neutral or protective effect on mortality, although this has not been confirmed in interventional studies needed to establish causality. The effect of obesity on other important outcomes such as quality of life has yet to be determined, and much less information on obesity and outcomes is available in the kidney transplantation population. Similarly, research on the optimal strategies and effects of weight loss in dialysis and kidney transplantation patients is at a nascent stage.

Nutrition and the kidney: recommendations for peritoneal dialysis

Protein energy wasting (PEW) is highly prevalent in peritoneal dialysis (PD) and is associated with poor outcomes, including hospitalization and mortality. Recognizing and diagnosing PEW in PD is important; although studies are limited, there are interventions that may be associated with improved outcomes. In this review of nutritional aspects of PD, we highlight some of the important causes of PEW and explore the current diagnostic tools that are used to assess PEW. Finally, we discuss the established and experimental therapies for PEW in PD.

Increase in BMI over time is associated with fluid overload and signs of wasting in incident peritoneal dialysis patients

OBJECTIVES

Peritoneal dialysis (PD) patients may suffer changes in nutritional status after starting PD. Several markers can be used to evaluate these modifications, such as body mass index (BMI), serum albumin, and serum creatinine. Fluid overload should be considered because it can overestimate or underestimate nutritional status. The objective of this study was to evaluate the BMI changes over time in incident PD patients and identify interactions among BMI, signs of fluid overload, serum albumin, and serum creatinine.

DESIGN

The study included a cohort of 1,997 incident PD patients of the BRAZPD recruited from 2004 to 2007. Sociodemographic data and BMI classification were obtained at baseline. The evolutions of BMI and body weight were assessed over a period of 29 months. Changes in the evolution were analyzed when a patient presented with albumin < 3.8 g/dL, creatinine < 7.0 mg/dL, or the presence of edema. Data analysis was performed using linear mixed-effects regression models as the main statistical procedure.

RESULTS

BMI increased over time (29 months) by an average of 0.05 kg/m(2) per month, and body weight increased by 0.11 kg/month for a total increase of 3.08 kg. BMI decreased by 0.12 kg/m(2) in the presence of albumin < 3.8 g/dL and by 0.38 kg/m(2) in the presence of creatinine < 7.0 mg/dL. BMI increased by 0.61 kg/m(2) in the presence of edema. BMI increased in the presence of edema and albumin < 3.8 mg/dL or edema and creatinine < 7.0 mg/dL.

CONCLUSIONS

There is a mean increase in the BMI of incident PD patients over time, and these changes may be, at least partly, due to fluid overload, leading to distortions of body weight. When the patients presented with lower serum albumin or creatinine levels, the BMI values were reduced, suggesting that a reduction in lean mass and an increase in fat mass may be occurring in these patients.

Two icodextrin exchanges per day in peritoneal dialysis patients with ultrafiltration failure: one center's experience and review of the literature

BACKGROUND

At present, only one exchange of an icodextrin-based solution is recommended to increase peritoneal ultrafiltration (UF) during long-dwell exchanges in peritoneal dialysis (PD) patients with impaired UF.

AIM

To review our experience with two icodextrin exchanges per day on net UF and body weight in PD patients with poor UF.

METHODS

Data were analyzed on nine patients with poor UF on chronic PD who were given two icodextrin exchanges per day for 6 months and had various clinical and biochemical parameters assessed monthly.

RESULTS

Administration of icodextrin twice daily reduced the body weight in six of nine patients by an average of 2.9 ± 1.2 kg, a reduction that was maintained throughout the study; two patients gained 0.5 kg; and, in one patient, the measurements were inadequate. Mean blood pressure was reduced. Mean serum creatinine increased slightly. Serum sodium levels decreased from a mean baseline level of 134 ± 3 to 132 ± 4 mmol/L at three and six months. Among the diabetics in this group, average daily insulin requirements were 44 ± 35 units/day at baseline and 40 ± 23 units/day after 6 months. Hb1Ac levels remained stable throughout the study period.

CONCLUSION

The use of two icodextrin exchanges per day reduced body weight in six of the nine patients and appeared to be safe. Long-term prospective studies are needed to assess the contribution of twice-daily icodextrin to the management of peritoneal dialysis patients with ultrafiltration failure and its long-term safety.

Metabolic syndrome predicts mortality in non-diabetic patients on continuous ambulatory peritoneal dialysis

BACKGROUND

Metabolic syndrome is associated with higher morbidity and mortality in the general population, but the corresponding effects in patients on dialysis have not been clearly defined. In this study, we prospectively investigated the effect of metabolic syndrome and its individual components on outcome in non-diabetic peritoneal dialysis (PD) patients. Method. The study subjects included 106 stable non-diabetic PD patients who had been on PD for >3 months. We measured baseline characteristics, blood pressure, fasting blood glucose, lipid profiles and high-sensitivity CRP (hsCRP), and defined metabolic syndrome using the modified National Cholesterol Education Program (Adult Treatment Panel III) criteria. Mortality, technical failure and hospitalization were evaluated during the follow-up period.

RESULTS

Metabolic syndrome was present in 50 patients (47.2%), and these showed higher baseline hsCRP levels (0.67; 95% CI: 0.50-0.94 versus 1.78 mg/dl; 95% CI: 1.21-2.57; P < 0.001). Patients with metabolic syndrome experienced significantly lower 5-year survival rates than patients without (90% versus 67%, P = 0.02), although these groups did not differ in peritonitis rates, technical failure or hospitalization. A Cox proportional hazards analysis identified the following as predictors of mortality: metabolic syndrome (RR: 3.39; 95% CI: 1.16-9.94; P = 0.02), baseline albumin (RR: 0.06; 95% CI: 0.01-0.30; P = 0.001) and baseline hsCRP levels (RR: 1.14; 95% CI: 1.07-1.22; P < 0.001).

CONCLUSION

Metabolic syndrome is prevalent and is a risk factor influencing long-term survival in non-diabetic PD patients.

Association of white blood cell count with metabolic syndrome in patients undergoing peritoneal dialysis

Metabolic syndrome is associated with an increased risk of diabetes and cardiovascular disease. Although some data suggest that the prevalence of metabolic syndrome is higher in patients undergoing peritoneal dialysis (PD), the factors related to this increased risk are not well elucidated. We therefore examined whether peripheral white blood cell (WBC) count is correlated with the risk of metabolic syndrome in nondiabetic PD patients. We enrolled 104 nondiabetic PD patients without current infections or chronic inflammatory diseases. Complete blood cell count, anthropometry, blood pressure, fasting glucose, insulin, and lipid profiles were measured. Metabolic syndrome was defined in accordance with the National Cholesterol Education Program (Adult Treatment Panel III) criteria. Metabolic syndrome was present in 49 patients (47.1%). Patients with metabolic syndrome had a higher WBC count and high-sensitivity C-reactive protein level. As the number of metabolic syndrome components increased, WBC count increased significantly. White blood cell count was significantly positively correlated with body mass index, insulin, homeostasis model assessment of insulin resistance, and triglyceride and negatively correlated with high-density lipoprotein cholesterol. The risk of metabolic syndrome increased significantly with a higher WBC count, resulting in an adjusted odds ratio of 1.65 (per 10(3)/muL increase, P = .002). These findings demonstrate that metabolic syndrome is prevalent among nondiabetic PD patients and that WBC count is strongly associated with metabolic syndrome and its components.

Icodextrin Improves Metabolic and Fluid Management in High and High-Average Transport Diabetic Patients

Background

Icodextrin-based solutions (ICO) have clinical and theoretical advantages over glucose-based solutions (GLU) in fluid and metabolic management of diabetic peritoneal dialysis (PD) patients; however, these advantages have not yet been tested in a randomized fashion.

Objective

To analyze the effects of ICO on metabolic and fluid control in high and high-average transport diabetic patients on continuous ambulatory PD (CAPD).

Patients and Methods

A 12-month, multicenter, open-label, randomized controlled trial was conducted to compare ICO ( n = 30) versus GLU ( n = 29) in diabetic CAPD patients with high-average and high peritoneal transport characteristics. The basic daily schedule was 3 × 2 L GLU (1.5%) and either 1 × 2 L ICO (7.5%) or 1 × 2 L GLU (2.5%) for the long-dwell exchange, with substitution of 2.5% or 4.25% for 1.5% GLU being allowed when clinically necessary. Variables related to metabolic and fluid control were measured each month.

Results

Groups were similar at baseline in all measured variables. More than 66% of the patients using GLU, but only 9% using ICO, needed prescriptions of higher glucose concentration solutions. Ultrafiltration (UF) was higher (198 ± 101 mL/day, p < 0.05) in the ICO group than in the GLU group over time. Changes from baseline were more pronounced in the ICO group than in the GLU group for extracellular fluid volume (0.23 ± 1.38 vs –1.0 ± 1.48 L, p < 0.01) and blood pressure (systolic 1.5 ± 24.0 vs –10.4 ± 30.0 mmHg, p < 0.01; diastolic 1.5 ± 13.5 vs –6.2 ± 14.2 mmHg, p < 0.01). Compared to baseline, patients in the ICO group had better metabolic control than those in the GLU group: glucose absorption was more reduced (–17 ± 44 vs –64 ± 35 g/day) as were insulin needs (3.6 ± 3.4 vs – 9.1 ± 4.7 U/day, p < 0.01), fasting serum glucose (8.3 ± 36.5 vs –37 ± 25.8 mg/dL, p < 0.01), triglycerides (54.5 ± 31.9 vs –54.7 ± 39.9 mg/dL, p < 0.01), and glycated hemoglobin (0.79% ± 0.79% vs –0.98% ± 0.51%, p < 0.01). Patients in the ICO group had fewer adverse events related to fluid and glucose control than patients in the GLU group.

Conclusion

Icodextrin represents a significant advantage in the management of high transport diabetic patients on PD, improving peritoneal UF and fluid control and reducing the burden of glucose overexposure, thereby facilitating metabolic control.

Solutes transport characteristics in peritoneal dialysis: variations in glucose and insulin serum levels

BACKGROUND

Differences in small solutes transport rate (SSTR) during peritoneal dialysis (PD) may affect water and solutes removal. Patients with high SSTR must rely on shorter dwell times and increased dialysate glucose concentrations to keep fluid balance. Glucose absorption during peritoneal dialysis (PD), besides affecting glucose and insulin metabolism, may induce weight gain. The study aimed at examining acute glucose and insulin serum level changes and other potential relationships in PD patients with diverse SSTR.

METHODS

This cross-sectional study used a modified peritoneal equilibration test (PET) that enrolled 34 prevalent PD patients. Zero, 15, 30, 60, 120, 180, and 240-minute glucose and insulin serum levels were measured. Insulin resistance index was assessed by the homeostasis model assessment (HOMA-IR) formula. SSTR categories were classified by quartiles of the four-hour dialysate/serum creatinine ratio (D(4)/P(Cr)). Demographic and clinical variables were evaluated, and the body mass index (BMI) was estimated. Correlations among variables of interest and categories of SSTR were explored.

RESULTS

Glucose serum levels were significantly different at 15, 30, and 60 minutes between high and low SSTR categories (p = 0.014, 0.009, and 0.022). Increased BMI (25.5 +/- 5.1) and insulin resistance [HOMA-IR = 2.60 (1.40-4.23)] were evidenced overall. Very strong to moderate correlations between insulin levels along the PET and HOMA-IR (r = 0.973, 0.834, 0.766, 0.728, 0.843, 0.857, 0.882) and BMI (r = 0.562, 0.459, 0.417, 0.370, 0.508, 0.514, 0.483) were disclosed. CONCLUSIONS; Early glucose serum levels were associated with SSTR during a PET. Overweight or obesity and insulin resistance were prevalent. An association between insulin serum levels and BMI was demonstrated.

Estimates of body water, fat-free mass, and body fat in patients on peritoneal dialysis by anthropometric formulas

BACKGROUND

Anthropometric formulas that are used to estimate body water in peritoneal dialysis patients can also be used to estimate fat-free mass and body fat. Evaluation of body composition by the anthropometric formulas rests on two assumptions: (1) fat contains no water, and (2) the water content of the fat-free mass is constant (72%).

METHODS

We compared estimates of body water, fat-free mass, and body fat by anthropometric formulas to estimates employing dilution of tracer substances to measure body water and standard methods to analyze body composition in studies performed on peritoneal dialysis patients. We also analyzed the potential errors of the estimates of body composition by the formulas.

RESULTS

Estimates of the average body composition provided by the anthropometric formulas agreed with estimates provided by the standard methods. However, these formulas have the potential of introducing large errors when estimating body composition in individuals differing from the average subject, either because the anthropometric formulas do not account for major determinants of body composition, such as physical exercise, nutrition, and catabolic illness, or because these formulas systematically overestimate body water in subjects who are obese or experiencing volume excess.

CONCLUSION

Anthropometric formulas currently in existence can provide only approximations of body composition and may be the sources of large errors in evaluating body composition in peritoneal dialysis patients. The potential errors include estimates of body water. These errors may alter the interpretation of urea kinetic studies in certain categories of peritoneal dialysis patients (e.g., obese subjects).

A randomized controlled trial to evaluate the efficacy and safety of icodextrin in peritoneal dialysis

BACKGROUND

This article presents the results of two randomized, double-blind, controlled studies conducted to compare the efficacy and long-term safety of icodextrin and 2.5% dextrose for the once-daily long dwell in continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD).

METHODS

Both studies were active-control comparisons of 7.5% icodextrin and 2.5% dextrose for the once-daily long dwell. The efficacy study was a 4-week evaluation of net ultrafiltration and peritoneal clearances of creatinine and urea nitrogen in 175 CAPD patients. The 52-week study in CAPD and APD patients examined the long-term safety of icodextrin and longer term effects, such as body weight and quality of life.

RESULTS

Mean net ultrafiltration (587.2 versus 346.2 mL, P < 0.001) and clearances of urea nitrogen (4.5 versus 4.1 mL/min, P < 0.001) and creatinine (4.0 versus 3.5 mL/min, P < 0.001) were increased significantly with icodextrin. Patients receiving icodextrin had no increase in weight after 52 weeks, in contrast to a weight gain of almost 2 kg in the dextrose group (P < 0.05). There were significantly fewer patients reporting edema in the icodextrin group compared with the dextrose group (6.3% versus 17.9%, P < 0.01). There were no statistically significant differences between groups for the incidence and severity of adverse events. There were small decreases in sodium and chloride and increases in alkaline phosphatase with icodextrin.

CONCLUSION

Icodextrin provides patients with greater fluid removal and small solute clearance, no weight gain over 52 weeks, and a decreased risk of edema.