Icodextrin: a review of its use in peritoneal dialysis

Early Initiation of Icodextrin Reduces Peritoneal Dialysis-Associated Peritonitis Risk: A Retrospective Cohort Study

INTRODUCTION

Peritonitis is a common and serious complication of peritoneal dialysis (PD) that leads to its discontinuation and death. Icodextrin (ICO) improves peritoneal ultrafiltration and its early use reduces mortality. However, its effectiveness in reducing PD-associated infections remains to be elucidated.

METHODS

This retrospective observational study enrolled patients who underwent PD between September 2011 and March 2020. The patients were classified into two groups: those who received ICO at the initiation of PD therapy (early ICO) and those who received ICO later or not at all (late/no ICO) and were followed up from PD induction until PD cessation, death, or 3 years had passed.

RESULTS

Of the 82 patients (age, 61 [53-72] years), 21 received early ICO. During follow-up (36 [14-36] months), the incidence of PD-associated peritonitis was 0.17 episodes per patient-year. Log-rank tests indicated that PD-associated peritonitis and tunnel infection (TI)-free survival rates were significantly better with the early use of ICO than with late/no ICO (p = 0.02 and p = 0.01, respectively). The early use of ICO remained significantly associated with decreased incidence of both peritonitis and TI (hazard ratio [HR], 0.19; 95% confidence interval [CI], 0.06-0.69 and HR, 0.10; 95% CI, 0.01-0.78, respectively) using Cox regression analysis adjusted for potential confounders.

CONCLUSION

Beginning ICO administration at the initiation of PD shows promise for mitigating the risks of PD-associated peritonitis and TI.

Acute Peritoneal Dialysis in a Patient with Severe Uremic Syndrome and Multiple Hemodialysis Access Failure

A 67-year-old woman was diagnosed with chronic kidney disease stage V, severe uremia syndrome, hyperkalemia, metabolic acidosis, suspected pulmonary oedema, and multiple hemodialysis access failure. The patient is in a condition that requires emergency hemodialysis, but the patient does not have any access to undergo hemodialysis. The patient then underwent acute peritoneal dialysis and received an adequate response. The patient continued continuous ambulatory peritoneal dialysis and responded well.

Icodextrin-induced acute generalized exanthematous pustulosis in a patient with peritoneal dialysis

Icodextrin has been widely prescribed for peritoneal dialysis (PD) patients with inadequate ultrafiltration, but icodextrin induced acute generalized exanthematous pustulosis (AGEP) has been not well recognized in clinical practice. We described a young-aged female with IgA nephropathy and end stage kidney disease under continuous automated peritoneal dialysis. She developed skin erythema with exfoliation over the groin 7th day after initiation of icodextrin based PD dialysate. Initially, her scaling skin lesion with pinhead-sized pustules affected the bilateral inguinal folds, and then it extended to general trunk accompanied by pruritus. She was admitted because of deterioration of skin lesion on 14th day of icodextrin exposure. She was afebrile and physical examination was notable for widespread erythematous papules with pruritus extending over her groins and trunk. Pertinent laboratory examination showed leukocytosis of 18 970 cells/μL with neutrophile count of 17 642 cells/μL (92.3%), and c-reactive-protein: 3.39 mg/dL. Skin biopsy revealed multifocal sub corneal abscess with papillary dermal edema, and upper-dermal neutrophilia with perivascular accentuation, consistent with the diagnosis of AGEP. After discontinuation of PD, she underwent temporary high-flux haemodialysis with treatment of steroid and antihistamine. Her dermatologic lesion resolved without any skin sequalae completely within 4 days, and she underwent icodextrin-free peritoneal dialysis at 17th day. This case highlighted the fact that icodextrin-induced AGEP should be early recognized to avoid inappropriate management.

Assessment and management of heart failure in patients with chronic kidney disease

Heart failure (HF) and chronic kidney disease (CKD) are two pathological conditions with a high prevalence in the general population. When they coexist in the same patient, a strict interplay between them is observed, such that patients affected require a clinical multidisciplinary and personalized management. The diagnosis of HF and CKD relies on signs and symptoms of the patient but several additional tools, such as blood-based biomarkers and imaging techniques, are needed to clarify and discriminate the main characteristics of these diseases. Improved survival due to new recommended drugs in HF has increasingly challenged physicians to manage patients with multiple diseases, especially in case of CKD. However, the safe administration of these drugs in patients with HF and CKD is often challenging. Knowing up to which values ​​of creatinine or renal clearance each drug can be administered is fundamental. With this review we sought to give an insight on this sizable and complex topic, in order to get clearer ideas and a more precise reference about the diagnostic assessment and therapeutic management of HF and CKD.

Melatonin decreases GSDME mediated mesothelial cell pyroptosis and prevents peritoneal fibrosis and ultrafiltration failure

Peritoneal fibrosis together with increased capillaries is the primary cause of peritoneal dialysis failure. Mesothelial cell loss is an initiating event for peritoneal fibrosis. We find that the elevated glucose concentrations in peritoneal dialysate drive mesothelial cell pyroptosis in a manner dependent on caspase-3 and Gasdermin E, driving downstream inflammatory responses, including the activation of macrophages. Moreover, pyroptosis is associated with elevated vascular endothelial growth factor A and C, two key factors in vascular angiogenesis and lymphatic vessel formation. GSDME deficiency mice are protected from high glucose induced peritoneal fibrosis and ultrafiltration failure. Application of melatonin abrogates mesothelial cell pyroptosis through a MT1R-mediated action, and successfully reduces peritoneal fibrosis and angiogenesis in an animal model while preserving dialysis efficacy. Mechanistically, melatonin treatment maintains mitochondrial integrity in mesothelial cells, meanwhile activating mTOR signaling through an increase in the glycolysis product dihydroxyacetone phosphate. These effects together with quenching free radicals by melatonin help mesothelial cells maintain a relatively stable internal environment in the face of high-glucose stress. Thus, Melatonin treatment holds some promise in preserving mesothelium integrity and in decreasing angiogenesis to protect peritoneum function in patients undergoing peritoneal dialysis.

Deciphering the structural and functional characteristics of an innovative small cluster branched α-glucan produced by sequential enzymatic synthesis

Highly branched α-glucan (HBAG) proved to be a promising material as an osmotic agent in peritoneal dialysis solutions. However, high resistance of HBAG to amylolytic enzymes might be a potential drawback for peritoneal dialysis due to its high degree of branching (20-30 %). To address this issue, we designed a small-clustered α-glucan (SCAG) with a relatively low molecular weight (Mw) and limited branching. Structural characteristics revealed that SCAG was successfully synthesized by modifying waxy rice starch (WRS) using sequential maltogenic α-amylase (MA) and starch branching enzyme (BE). The Mw of SCAG was 1.40 × 10⁵ Da, and its (α1 → 6) bonds ratio was 8.93 %, which was below that of HBAG. A relatively short branch distribution was observed in SCAG (CL = 6.27). Short-range orderliness of WRS was reduced from 0.749 to 0.322 with the MABE incubation. Additionally, SCAG had an extremely low viscosity (~12 cP) and nearly no retrogradation. Although the resistance of SCAG to amylolytic enzymes was enhanced by 15.22 % compared with native WRS, the extent was significantly lower than that of HBAG in previous studies. These new findings demonstrate the potential of SCAG as a novel functional α-glucan in food and pharmaceutical applications.

Five Things to Know About Volume Overload in Peritoneal Dialysis

Volume overload in peritoneal dialysis (PD) is common and associated with significant morbidity and mortality. If left untreated, it can result in premature technique failure in patients receiving PD. Practitioners should be aware of common causes and formulate a stepwise approach in the management of volume overload.

Mild sodium reduction in peritoneal dialysis solution improves hypertension in end stage kidney disease: a case-report study

Introduction

Blood Pressure (BP) control is largely unsatisfied in End Stage Kidney Disease (ESKD) principally due to sodium retention. Peritoneal Dialysis (PD) is the most common type of home dialysis, using a peritoneal membrane to remove sodium, though sodium removal remains challenging.

Methods

This is a case-study reporting two consecutive ESKD patients treated by a novel peritoneal PD solution with a mildly reduced sodium content (130 mmol/L) to treat hypertension.

Results

In the first case, a 78-year-old woman treated by Continuous Ambulatory PD (CAPD) with standard solution (three 4 h-dwells per day 1.36% glucose 132 mmol/L) showed resistant hypertension confirmed by ambulatory blood pressure monitoring (ABPM), reporting 24 h-BP: 152/81 mmHg, day-BP:151/83 mmHg and night-ABP: 153/75 mmHg, with inversion of the circadian systolic BP rhythm (1.01), despite use of three anti-hypertensives and a diuretic at adequate doses. No sign of hypervolemia was evident. We then switched from standard PD to low-sodium solution in all daily dwells. A six-months low-sodium CAPD enabled us to reduce diurnal (134/75 mmHg) and nocturnal BP (122/67 mmHg), restoring the circadian BP rhythm, with no change in ultrafiltration or residual diuresis. Diet and drug prescription were unmodified too.

The second case was a 61-year-old woman in standard CAPD (three 5 h-dwells per day) suffering from hypertension confirmed by ABPM (mean 24 h-ABP: 139/84 mmHg; mean day-ABP:144/88 mmHg and mean night-ABP:124/70 mmHg). She was switched from 132-Na CAPD to 130-Na CAPD, not changing dialysis schedule. No fluid expansion was evident. During low-sodium CAPD, antihypertensive therapy (amlodipine 10 mg and Olmesartan 20 mg) has been reduced until complete suspension. After 6 months, we repeated ABPM showing a substantial reduction in mean 24 h-ABP (117/69 mmHg), mean diurnal ABP (119/75 mmHg) and mean nocturnal ABP (111/70 mmHg). Ultrafiltration and residual diuresis remained unmodified. No side effects were reported in either cases.

Conclusions

This case-report study suggests that mild low-sodium CAPD might reduce BP in hypertensive ESKD patients.

Use of icodextrin solution to evaluate peritoneal transport capacity

Peritoneal equilibration test (PET) is the gold standard for evaluating peritoneal transport, and measurement of the drain volume after 4-h dwell time with glucose 4.25% is a simple means of evaluating failure of ultrafiltration. The study objective was to verify if the measurement of the volume drained after 4 h dwell of icodextrin at 7.5% (ICO), has a better correlation with the parameters of PET. Patients in a peritoneal dialysis program (N = 35) underwent three procedures: PET; determination of the drain volume after a 4-h dwell with glucose 4.25%; and determination of the drain volume after a 4-h dwell with ICO. Among patients who were classified as high transporters, the ultrafiltration volume was greater after ICO use. The ICO ultrafiltration volume correlated negatively with the ratio between the 4- and 0-h dialysate glucose concentrations (D4/D0 ratio, r = -0.579; P = 0.002), correlating positively with the dialysate-to-plasma ratio for creatinine (D/PCr ratio, r = 0.474; P = 0.002). For ICO, the area under the receiver operating characteristic curve was 0.867 and 0.792 for the D/PCr and D4/D0 ratios (P < 0.0001 and P = 0.004, respectively), compared with 0.738 and 0.710 for glucose 4.25% (P = 0.020 and P = 0.041, respectively). A cut-off volume of 141 mL discriminated high/high-average transporters from low/low-average transporters. Volume drained after ICO use better predicts peritoneal transport patterns than does that drained after the use of glucose 4.25%.

Incidence and mortality of new-onset glucose disorders in peritoneal dialysis patients in China: a meta-analysis

Background

Dialysis patients are at high risk of developing glucose metabolism disturbances (GMDs), such as diabetes mellitus (DM), impaired fast glucose (IFG), and impaired glucose tolerance (IGT). However, it is unclear about the incidence of GMDs in Chinese patients with peritoneal dialysis (PD), as well as the influence of new-onset DM (NODM) on the prognosis of PD patients. Therefore, we conducted this meta-analysis to address these issues.

Methods

A comprehensive literature search was conducted using PubMed, Embase, Web of Science, SinoMed, and CNKI database for studies that evaluated the incidence of GMDs and mortality in patients with PD. Results were expressed as hazard ratio (HR), risk ratio (RR), or estimate (ES) with 95% confidence intervals (95%CIs).Meta-analysis was performed using a fixed-effects or random-effects model to pool the estimate.

Results

Fifteen studies met the inclusion criteria and were included in this meta-analysis. Pooled results showed that, the incidences of NODM, NOIGT, and NOIFG were 12% (95%CI: 9, 15%; P < 0.001), 17% (95%CI: 4, 10%; P < 0.001) and 32% (95%CI: 3, 30%, P < 0.001), respectively. Compared with patients without NODM, PD patients with NODM had an increased risk of mortality (HR = 1.59, 95%CI: 1.28, 1.98; P < 0.001). There was no significant difference in the incidence of NODM between PD and hemodialysis (HD) patients (RR = 1.23, 95%CI: 0.61, 2.51; P = 0.562).

Conclusion

Dialysis patients in China had an increased risk of developing GMDs, however, the dialysis modality did not have any significant impact on the incidence of NODM. NODM increased the mortality risk in patients undergoing PD. Thus, physicians should pay attention to the plasma glucose level in patients undergoing dialysis.

Injured tissues favor cancer cell implantation via fibrin deposits on scar zones

AIM

Evaluation of fibrin role on cancer cells implantation in injured tissues and studying the molecular mechanism of cancer cell interaction with the peritoneal damage.

MATERIAL AND METHODS

Mouse colon cancer (CT26) and human mesothelial cells (HMCs) were used. CT26 cells were implanted on injured peritoneal zones. Icodextrin was used as a lubricant. For in vitro studies, fibrin clots from human plasma were used. The cell-fibrin interaction was observed by optical, electronic, and confocal microscopies. Aprotinin was used as a plasmin inhibitor. Hemostasis impact quantified by (1) the fibrin degradation product D-Dimer and PAR expression in HMCs; (2) the expression of plasminogen activator (PA) and its inhibitor (PAI-1) in cancer cells by qPCR and in supernatants through ELISA after in vitro HMC incubation with 2U of thrombin for 24 h.

RESULTS

(i) Cancer cell lines were adhered and implanted into the wound area in vivo in both the incision and peeling zones of the peritoneum and on the fibrin network in vitro. (ii) Icodextrin significantly inhibited cancer nodule formation in the scar and the incision or peritoneal damaged zones after surgery. (iii) In in vitro studies, cancer cell interaction with the fibrin clot generated a lysed area, causing an increase in plasmin-dependent fibrinolysis measured by D-dimer levels in the supernatants that was inhibited by aprotinin. (iv) Aprotinin inhibited cell-fibrin interaction and invasion. (v) Thrombin upregulates PAI-1 and downregulates PA expression in HMC.

CONCLUSION

Injured tissues favor cancer cell implantation through generated fibrin. Fibrin-cancer cells adhesion can be inhibited by icodextrin.

Barriers to Utilization of Chronic Peritoneal Dialysis in Network #1, New England

Objective

The percentage of prevalent end-stage renal disease (ESRD) patients maintained on chronic peritoneal dialysis (CPD) therapy in the United States declined from 15% in 1991 to 8.1% in 2002. Previous studies indicate that nephrologists in the United States feel 32.6% of prevalent ESRD patients should be on CPD therapy. The present study was designed to better understand the reasons for the discrepancy in actual versus desired prevalence of CPD utilization.

Methods

The medical directors of all dialysis centers in New England were mailed a questionnaire about the nephrologists’ opinions concerning the percentage of patients that should be maintained on CPD therapy, reasons that limited patients’ selection of CPD as initial therapy, and concerns about the current status of CPD therapy. The nephrologists were also invited to free text any other comments or concerns.

Results

A total of 117 questionnaires were sent; 59 (50.4%) were returned. These medical directors cared for a median of 10 (range 1 – 100) patients on CPD therapy, meaning 15% of dialysis patients in New England are maintained on CPD therapy. The medical directors felt that 29% (range 10% – 50%) of prevalent ESRD patients should be maintained on CPD therapy. The most common reasons cited by the nephrologists as barriers to CPD therapy included patient preference (54%), contraindications to performing CPD therapy (32%), poor social support (31%), significant comorbid disease (20%), late referrals and acute hospital starts (19%), problems with education re chronic kidney disease (12%), and problems with the structure and organization of CPD facilities (12%). These same medical directors stated that concerns about technique failure (25%), long-term viability of CPD therapy (25%), and mortality rates of CPD patients (17%) impacted on their use of CPD therapy as renal replacement therapy for patients with ESRD.

Conclusion

Nephrologists in New England felt that 29% of prevalent ESRD patients should be maintained on CPD therapy, yet the actual incidence of CPD utilization in New England is 15%. A variety of factors were cited by the nephrologists as important reasons limiting CPD utilization. These nephrologists were also concerned about technique failure and long-term viability of CPD therapy. It is necessary that we look closely at each domain cited by the nephrologists if CPD therapy is to remain a viable option for patients with ESRD in the United States.

Cost-Utility Analysis of Continuous Ambulatory Peritoneal Dialysis and Automated Peritoneal Dialysis for Thai Patients With End-Stage Renal Disease

BACKGROUND

Continuous ambulatory peritoneal dialysis (CAPD) is the first option for patients with end-stage renal disease under the benefit package of Thailand. Nevertheless, automated peritoneal dialysis (APD) may benefit these patients in terms of both medical and quality-of-life aspects, but it is more expensive. The economic evidence for the comparison between CAPD and APD is not inconclusive. Thus, this study aims to evaluate the cost-effectiveness of CAPD compared with APD in PD patients.

OBJECTIVES

To assess the health-related quality of life and costs between patients treated with CAPD and APD.

METHODS

A Markov model was developed to evaluate the cost-effectiveness of CAPD and APD from the societal perspective. Costs and outcomes were calculated over a lifetime horizon and discounted at an annual rate of 3%. The outcomes were presented as quality-adjusted life-years (QALYs) of CAPD and APD. Utility scores were calculated from the utility values of the 5-level EuroQol questionnaire. A probabilistic sensitivity analysis using 5000 Monte Carlo simulations was performed to evaluate the stability of the results.

RESULTS

The costs of APD and CAPD were 12 868 080 and 11 144 786 Thai baht, respectively, whereas the QALYs were 24.28 and 24.72 QALYs, respectively. APD was more costly but less effective than CAPD. The most sensitive parameter was direct medical cost of outpatient visits. When the willingness-to-pay threshold was 160 000 Thai baht per QALY, the probability of APD providing a cost-effective alternative to CAPD was 19%.

CONCLUSION

APD was not a cost-effective strategy as compared with CAPD at the current Thai threshold. These findings should encourage clinicians and policy makers to encompass the use of CAPD as a good value for money for PD treatment.

High Pyridine Generation in Ceftazidime-Icodextrin Admixtures Used to Treat Peritoneal Dialysis-associated Peritonitis

PURPOSE

To investigate the amount of pyridine generated from degradation of ceftazidime in icodextrin peritoneal dialysis (PD) solutions.

METHODS

PD solutions that contained 1 and 1.5 g of ceftazidime were stored at 25 °C for 12 hours and then at 37 °C for 14 hours. An aliquot was withdrawn at predefined time points and analyzed for the concentrations of ceftazidime and pyridine.

FINDINGS

The amount of pyridine generated was >225% and 400% of its maximum recommended daily exposure in the 1- and 1.5-g ceftazidime-PD admixtures, respectively.

IMPLICATIONS

Until these results are confirmed with appropriate in vivo studies, intermittent intraperitoneal dosing of ceftazidime admixed with icodextrin should be used with caution and appropriate clinical monitoring or a suitable alternative antibiotic should be used.

Risk of new-onset diabetes in end-stage renal disease patients undergoing dialysis: analysis from registry data of Taiwan

Background

This study compared the risk of developing new-onset diabetes between hemodialysis (HD) and peritoneal dialysis (PD) patients. We further investigated the effectiveness of icodextrin in reducing the risk of new-onset diabetes in PD patients.

Methods

From the Taiwan health insurance database, 36 879 incident HD patients and 6382 incident PD patients from 2000 to 2010 were identified as study cohorts. We further selected an additional HD cohort matched by propensity scores (PSs) of PD patients. Incidence rates and hazard ratios (HRs) of new-onset diabetes were assessed among cohorts and between icodextrin users and nonusers by the end of 2011.

Results

For the unmatched cohorts, the incidence of new-onset diabetes was higher in PD patients than in HD patients (9.16 versus 8.18 per 1000 person-years), with an adjusted HR of 1.51 (95% CI 1.30-1.75) for PD patients. For the PS-matched cohorts, the corresponding incidence rates were 9.43 and 5.90 per 1000 person-years, respectively, with an adjusted HR of 1.61 (95% CI 1.32-1.97). Among PD patients, the incidence was lower in icodextrin users than in nonusers (6.22 versus 12.1 per 1000 person-years), with an adjusted HR of 0.66 (95% CI 0.50-0.88) for users.

Conclusions

Our study suggests that PD patients are at a higher risk of developing new-onset diabetes than HD patients. Icodextrin is recommended for PD patients to reduce the risk of new-onset diabetes.

Icodextrin Is Associated with a Lower Mortality Rate in Peritoneal Dialysis Patients

Background:Icodextrin (ICO) improves fluid removal in peritoneal dialysis (PD) patients. However, whether physiological benefits of ICO translate into patient survival remains unclear. We examine the association of ICO and clinical outcomes.Methods:We identified patients who initiated long-term PD from the National Health Insurance Research Database of Taiwan. We matched ICO users with non-users according to propensity score and survival status when ICO was prescribed. We utilized time-dependent analyses to avoid immortal time bias. Additional competing risk models were utilized for the outcomes except for death. The outcomes of interest were time to death, technique failure, peritonitis, major adverse cardiovascular events (MACE), and hospitalization.Results:A total of 4,914 PD patients were enrolled and 2,836 PD patients (57.7%) were identified as ICO users. The ICO users had significantly better overall survival (hazard ratio [HR] 0.74; 95% confidence interval [CI] 0.63 - 0.86), especially among early ICO users (HR 0.64; 95% CI 0.54 - 0.77, p value for interaction: 0.007). The ICO users were associated with higher risk of peritonitis (subdistribution HR 1.22, 95% CI 1.06 - 1.14) and hospitalization (subdistribution HR 1.14, 95% CI 1.05 - 1.24), considering competing risk of death. However, when considering ICO use as a time-varying covariate, ICO users shared similar risks for technique failure, peritonitis, MACE, and hospitalization as non-users. The effect of ICO on mortality was especially prominent among those early users.Conclusions:After adjustments for immortal time biases, ICO users were significantly associated with approximately 20% reduction in mortality, especially among early users.

Peritoneal and Systemic Responses of Obese Type II Diabetic Rats to Chronic Exposure to a Hyperbranched Polyglycerol-Based Dialysis Solution

Metabolic syndrome (MetS) is commonly observed among peritoneal dialysis (PD) patients, and hyperbranched polyglycerol (HPG) is a promising glucose-sparing osmotic agent for PD. However, the biocompatibility of a HPG-based PD solution (HPG) in subjects with MetS has not been investigated. This study compared the local and systemic effects of a HPG solution with conventional physioneal (PYS) and icodextrin (ICO) PD solutions in rats with MetS. Obese type 2 diabetic ZSF1 rats received a daily intraperitoneal injection of PD solutions (10 mL) for 3 months. The peritoneal membrane (PM) function was determined by ultrafiltration (UF), and the systemic responses were determined by profiling blood metabolic substances, cytokines and oxidative status. Tissue damage was assessed by histology. At the end of the 3-month treatment with PD solutions, PM damage and UF loss in both the PYS and ICO groups were greater than those in the HPG group. Blood analyses showed that compared to the baseline control, the rats in the HPG group exhibited a significant decrease only in serum albumin and IL-6 and a minor glomerular injury, whereas in both the PYS and ICO groups, there were more significant decreases in serum albumin, antioxidant activity, IL-6, KC/GRO (CXCL1) and TNF-α (in ICO only) as well as a more substantial glomerular injury compared to the HPG group. Furthermore, PYS increased serum creatinine, serum glucose and urine production. In conclusion, compared to PYS or ICO solutions, the HPG solution had less adverse effects locally on the PM and systemically on distant organs (e.g. kidneys) and the plasma oxidative status in rats with MetS.

Hypertension in Pediatric Dialysis Patients: Etiology, Evaluation, and Management

PURPOSE OF REVIEW

Review epidemiology, pathophysiology, and management of hypertension in the pediatric dialysis population.

RECENT FINDINGS

Interdialytic blood pressure measurement, especially with ambulatory blood pressure monitoring, is the gold standard to assess for hypertension. Tools to assess dry weight aid in achievement of euvolemia, the primary therapy for management of hypertension. Persistent hypertension should be treated with antihypertensive medications and potentially with native nephrectomies. Cardiovascular disease continues to be the primary cause of morbidity and mortality in the dialysis population with hypertension as an important modifiable factor. Achievement on dry weight and limiting both aggressiveness of interdialytic weight gain and ultrafiltration rate underlie the best approach. Tools to assess volume status beyond clinical assessment have shown promise in achieving euvolemia. When hypertension persists despite achievement of euvolemia, antihypertensive medications may be required and in some cases native nephrectomies. Future studies in children are needed to determine the best antihypertensive class and ideal rate of ultrafiltration on hemodialysis towards achievement of normotension and reduction of cardiovascular risk.

Comparison of survival between hemodialysis and peritoneal dialysis patients with end-stage renal disease in the era of icodextrin treatment

BACKGROUND

Icodextrin could reduce the risk of technique failure and improve patient survival in peritoneal dialysis (PD) patients. This study compared the survival between incident hemodialysis (HD) and PD patients, with and without diabetes, in the era of icodextrin treatment.

METHODS

From the Taiwan health insurance database, 53,103 incident end-stage renal disease patients undergoing dialysis were identified from 2005 to 2010. The mortality risks among HD and PD patients with or without icodextrin treatment were compared. The follow-up period started from the date of dialysis initiation to December 31, 2011. The competing-risks regression model was used to estimate the subhazard ratio (SHR) of death with considering renal transplantation as a competing event.

RESULTS

Compared with the corresponding HD patients, mortality risks were higher in diabetic PD patients with icodextrin treatment (Bonferroni adjusted SHR=1.16, 98.3% CI=1.04-1.30) and without the treatment (Bonferroni adjusted SHR=1.35, 98.3% CI=1.16-1.57), particularly for elderly patients. Mortality risks for patients without diabetes were not different among the three cohorts. The time-dependent competing-risks model showed that PD patients with icodextrin treatment exhibited a reduced risk of death for diabetic patients, compared with those without icodextrin treatment (adjusted SHR=0.84, 95% CI=0.72-0.97).

CONCLUSIONS

Icodextrin could attenuate the survival disadvantage for PD relative to HD in diabetic patients, particularly for the elderly patients.

[Icodextrin: What arguments for and against its use as an osmotic agent in peritoneal dialysis]

Icodextrin is a glucose polymer derived from starch that is used as an osmotic agent in peritoneal dialysis. Its high molecular weight limits blood absorption and is useful for long dwell since there is few osmotic gradient dispersal. Its benefits are numerous: ltrafiltration optimization and better salt and water control especially in anuric patients with a high peritoneal permeability and also in case of infectious peritonitis, glucose sparing with less metabolic complications and a better preservation of peritoneal membrane, better biocompatibility. However it should not be forgotten that icodextrin has also side effects that must be known: allergies, cases of aseptic peritonitis, overintense water and salt depletion, lymphatic absorption of icodextrin and its metabolites (including maltose) with a risk of false capillary glucose rate estimation and a moderate increase in plasma osmolality. That is why it is not recommended now to use more than one daily icodextrin dwell. Nevertheless, several dialysis units use icodextrin in more than one daily dwell, especially in patients with an important ultrafiltration loss or in those in whom glucose sparing is essential. It seems to profit them with no more side effects. A large multicenter trial is in progress to test the efficacy and safety of icodextrin dwell twice a day in elder incident patients in peritoneal dialysis (DIDo). Moreover, icodextrin is also used combined with glucose in a long dwell (bimodal ultrafiltration) with encouraging results in terms of ultrafiltration and glucose sparing.

Risk of and Fatality from Acute Pancreatitis in Long-Term Hemodialysis and Peritoneal Dialysis Patients

BACKGROUND

This study was conducted to evaluate the risk of developing acute pancreatitis (AP) and the fatality from AP in hemodialysis (HD) and peritoneal dialysis (PD) patients, using the claims data of Taiwan National Health Insurance.

METHODS

From patients with newly diagnosed end-stage renal disease (ESRD) in 2000-2010, we identified a PD cohort (N = 9,766), a HD cohort (N = 18,841), and a control cohort (N = 114,386) matched by sex, age, and the diagnosis year of the PD cohort. We also established another 2 cohorts with 9,744 PD patients and 9,744 propensity score-matched HD patients. The incident AP and fatality from AP were evaluated for all cohorts by the end of 2011.

RESULTS

The adjusted hazard ratios (HRs) of acute pancreatitis were 5.68 (95% confidence interval [CI] = 5.05 - 6.39), 4.91 (95% CI = 4.32 - 5.59), and 7.47 (95% CI = 6.48 - 8.62) in the all dialysis, HD, and PD patients, compared with the controls, respectively. Peritoneal dialysis patients had an adjusted HR of 1.41 (95% CI = 1.21 - 1.65) for AP, compared with propensity score-matched HD patients. Peritoneal dialysis patients under icodextrin treatment had a lower incidence of AP than those without the treatment, with an adjusted HR of 0.59 (95% CI = 0.47 - 0.73). There was no significant difference in the 30-day mortality from AP between HD and PD patients.

CONCLUSIONS

Peritoneal dialysis patients were at a higher risk of developing AP than HD patients. Icodextrin solution could reduce the risk of developing AP in PD patients.

Use of Toll-like receptor assays for the detection of bacterial contaminations in icodextrin batches released for peritoneal dialysis

•

Monocyte test assays were poorly efficient for the detection of little bacterial contamination in icodextrin batches.

•

TLR2- and TLR4-transfected cell lines were appropriate for detecting PGN and LPS contaminations.

•

Mutanolysin treatment of icodextrins enhanced the response of TLR2-transfected cells to contaminating PGN.

•

Using TLR-transfected cell lines is a valuable approach for selecting icodextrin batches for peritoneal dialysis solutions.

Icodextrin is a starch derivative used for preparing solutions of peritoneal dialysis. Unfortunately, peptidoglycans (PGN) and lipopolysaccharides (LPS) have been reported to contaminate certain icodextrin batches and to contribute to the development of sterile peritonitis. The decision of selecting or rejecting icodextrin batches is however difficult, because of limitations in the detection of these bacterial contaminants. Besides monocyte activation tests of cytokine release, a number of bio-assays using stably TLR-transfected cell lines have been developed. Here, we compared the efficacy of TLR2- and TLR4-transfected cells to detect bacterial contamination with the responses of monocytes exposed to the same icodextrin samples. In contrast to monocyte models of cytokine release, we found that TLR2- and TLR4-transfected cell lines are highly sensitive to detect little PGN and LPS contaminations in the presence of icodextrin. With the intent to increase PGN reactivity, mutanolysin was used to generate soluble fragments in icodextrin samples. We found that such an enzymatic treatment led to an enhanced response of TLR2-transfected cells, even though parental icodextrin samples were poorly reactive. Altogether, these findings indicate that the use of TLR2- and TLR4-transfected cell lines is a valuable approach for helping to the decision of selecting icodextrin batches for peritoneal dialysis.

Fluid overload as a major target in management of cardiorenal syndrome: Implications for the practice of peritoneal dialysis

Congestion is an integral component of cardiorenal syndrome and portends an adverse impact on the outcomes. Recent studies suggest that congestion has the ability of modulating the interactions between the kidney and the heart in this setting. Peritoneal dialysis (PD) is a home-based therapeutic modality that is not only offered to patients with end-stage renal disease to provide solute clearance and ultrafiltration, but it has also been used in patients with refractory heart failure and fluid overload to help optimize volume status. Several uncontrolled studies and case series have so far evaluated the role of PD in management of hypervolemia for patients with heart failure. They have generally reported favorable results in this setting. However, the data on the outcomes of patients with end-stage renal disease and concomitant heart failure is mixed, and the proposed theoretical advantages of PD might not translate into improved clinical endpoints. Congestion is prevalent in this patient population and has a significant effect on their survival. As studies suggest that a significant subset of patients with end-stage renal disease who receive PD therapy are hypervolemic, suboptimal management of congestion could at least in part explain these conflicting results. PD is a highly flexible therapeutic modality and the choice of techniques, regimens, and solutions can affect its ability for optimization of fluid status. This article provides an overview of the currently available data on the role and clinical relevance of congestion in patients with cardiorenal syndrome and reviews potential options to enhance decongestion in these patients.

The glycogen of Galdieria sulphuraria as alternative to starch for the production of slowly digestible and resistant glucose polymers

Highly branched glucose polymers produced from starch are applied in various products, such as peritoneal dialysis solutions and sports drinks. Due to its insoluble, granular nature, the use of native starch as substrate requires an energy consuming pre-treatment to achieve solubilization at the expense of process costs. Glycogen, like starch, is also a natural glucose polymer that shows more favorable features, since it is readily soluble in cold water and more accessible by enzymes. The extremophilic red microalga Galdieria sulphuraria accumulates large amounts of a small, highly branched glycogen that could represent a good alternative to starch as substrate for the production of highly branched glucose polymers. In the present work, we analyzed the structure-properties relationship of this glycogen in its native form and after treatment with amyloglucosidase and compared it to highly branched polymers produced from potato starch. Glycogen showed lower susceptibility to digestive enzymes and significantly decreased viscosity in solution compared to polymers derived from starch, properties conferred by its shorter side chains and higher branch density. The action of amyloglucosidase on native glycogen was somewhat limited due to the high branch density but resulted in the production of a hyperbranched polymer that was virtually resistant to digestive enzymes.

Stability of Vancomycin in Icodextrin Peritoneal Dialysis Solution

Background:

Icodextrin is a glucose polymer used as an alternative osmotic agent in peritoneal dialysis (PD) solutions. There are few data regarding the long-term stability of vancomycin in icodextrin PD solution.

Objective:

To determine the chemical stability of vancomycin in icodextrin PD solution in polyvinyl chloride containers over a 7 day period at 4, 24, and 37 °C.

Methods:

Study samples were prepared by adding 2000 mg vancomycin HCl to commercially available 2.0 L bags of icodextrin 7.5% PD solution. Nine bags were prepared and stored in the following conditions: 3 under refrigeration (5 °C), 3 at room temperature (24 °C), and 3 at body temperature (37 °C). Samples were withdrawn from each bag immediately after preparation and at predetermined intervals over the subsequent 7 days. Solutions were visually inspected for precipitation, cloudiness, or discoloration at each sampling interval. Total concentration of vancomycin in dialysate fluid was determined by high performance liquid chromatography.

Results:

Under refrigeration, a mean ± SD of 99.7% ± 0.5% of the initial vancomycin concentration remained at 168 hours (7 days). At room temperature, 97.5% ± 3.4% remained at 168 hours. At body temperature, 94.3% ± 3.9% remained at 24 hours. Stability was not assessed beyond these time points.

Conclusions:

Premixed vancomycin-icodextrin PD solutions, whether stored refrigerated or at room temperature, were found to be stable for up to 7 days. However, we recommend that these solutions be kept refrigerated whenever possible. Solutions stored at body temperature were stable for up to 24 hours, permitting the practice of prewarming solutions prior to administration.

Chemistry and clinical relevance of carbohydrate degradation in drugs

Carbohydrate degradation products are formed during heat sterilization in drugs containing (poly-)glucose as osmotic agents. Given this situation, peritoneal dialysis fluids (PDFs) and infusion fluids are of particular clinical relevance, because these drugs deliver process contaminants either over a longer period or directly into the circulation of patients who are critically ill. For the development of suitable mitigation strategies, it is important to understand the reaction mechanisms of carbohydrate degradation during sterilization and how the resulting products interact with physiological targets at the molecular level. Furthermore, reliable, comprehensive, and highly sensitive quantification methods are required for product control and toxicological evaluation.

Falsely Elevated Glucose Concentrations in Peritoneal Dialysis Patients Using Icodextrin

BACKGROUND

Peritoneal dialysis (PD) is used as an alternative to hemodialysis in end-stage renal disease (ESRD). Icodextrin has been used as a hyperosmotic agent in PD. The aim of the study was to assess two different point-of-care testing (POCT) glucose strips, affected and not affected by icodextrin, with serum glucose concentrations of the patients using and not using icodextrin.

METHODS

Fifty-two chronic ambulatory peritoneal dialysis (CAPD) patients using icodextrin (Extraneal®) and 20 CAPD patients using another hyperosmotic fluid (Dianeal®) were included in the study. Duplicate capillary and serum glucose concentrations were measured with two different POCT glucose strips and central laboratory hexokinase method. Assay principles of glucose strips were based on glucose dehydrogenase-pyrroloquinoline quinone (GDH-PQQ) and a mutant variant of GDH (Mut Q-GDH). The results of both strips were compared with those of hexokinase method.

RESULTS

Regression equations between POCT and hexokinase methods in icodextrin group were y = 2.55x + 1.12 mmol/l and y = 1.057x + 0.16 mmol/l for the GDH-PQQ and Mut Q-GDH methods, respectively. The mean difference between the results of hexokinase and those of GDH-PQQ and Mut Q-GDH in icodextrin group was 3.41 ± 1.56 and 0.72 ± 0.64 mmol/l, respectively. However, the mean differences were found much lower in the control group; 0.64 mmol/l for GDH-PQQ and 0.52 mmol/l for Mut Q-GDH.

CONCLUSION

Compared to GDH-PQQ, glucose strips of Mut Q-GDH correlated better with hexokinase method in PD patients using icodextrin.

Improved burn wound healing by the antimicrobial peptide LLKKK18 released from conjugates with dextrin embedded in a carbopol gel

Antimicrobial peptides (AMPs) are good candidates to treat burn wounds, a major cause of morbidity, impaired life quality and resources consumption in developed countries. We took advantage of a commercially available hydrogel, Carbopol®, a vehicle for topical administration that maintains a moist environment within the wound site. We hypothesized that the incorporation of LLKKK18 conjugated to dextrin would improve the healing process in rat burns. Whereas the hydrogel improves healing, LLKKK18 released from the dextrin conjugates further accelerated wound closure, and simultaneously improving the quality of healing. Indeed, the release of LLKKK18 reduced oxidative stress and inflammation (low neutrophil and macrophage infiltration and pro-inflammatory cytokines levels). Importantly, it induced a faster resolution of the inflammatory stage through early M2 macrophage recruitment. In addition, LLKKK18 stimulated angiogenesis (increased VEGF and microvessel development in vivo). Moreover, collagen staining evaluated by Masson's Trichrome was visually much more intense after treatment with LLKKK18, suggesting higher collagen deposition. Overall, we generated an effective, safe and inexpensive formulation that maintains a moist environment in the wound, easy to apply and remove, and with potential to prevent infection due to the presence of an antimicrobial peptide. These findings propel us to further study this LLKKK18-containing formulation, setting the foundations towards a potential therapeutic approach for burn wound treatment.

STATEMENT OF SIGNIFICANCE

This work presents a newly developed formulation that holds great potential as a therapeutic approach for burn treatment. It is based on the sustained delivery of an antimicrobial peptide - LLKKK18 - from conjugates with dextrin, after degradation of dextrin backbone upon exposure to wound α-amylases. Conjugates were further embedded in Carbopol®, a commercially available hydrogel, suitable for topical administration and that provides a moist environment to the wound. Overall, we obtained an efficient, safe and non-expensive formulation that improves burn wound healing, maintains a moist environment within the wound, is easy to apply-and-remove, and has potential to prevent infection due to the presence of an antimicrobial peptide. Importantly, this is the first time the wound healing ability of LLKKK18 is demonstrated and that its main mechanisms of action are identified.

Stimulus-Responsive, Biodegradable, Biocompatible, Covalently Cross-Linked Hydrogel Based on Dextrin and Poly(N-isopropylacrylamide) for in Vitro/in Vivo Controlled Drug Release

A novel stimulus-sensitive covalently cross-linked hydrogel derived from dextrin, N-isopropylacrylamide, and N,N'-methylene bis(acrylamide) (c-Dxt/pNIPAm), has been synthesized via Michael type addition reaction for controlled drug release application. The chemical structure of c-Dxt/pNIPAm has been confirmed through Fourier transform infrared (FTIR) spectroscopy and (1)H and (13)C NMR spectral analyses. The surface morphology of the hydrogel has been studied by field emission scanning electron microscopic (FE-SEM) and environmental scanning electron microscopic (E-SEM) analyses. The stimulus responsiveness of the hydrogel was studied through equilibrium swelling in various pH media at 25 and 37 °C. Rheological study was performed to measure the gel strength and gelation time. Noncytotoxicity of c-Dxt/pNIPAm hydrogel has been studied using human mesenchymal stem cells (hMSCs). The biodegradability of c-Dxt/pNIPAm was confirmed using hen egg lysozyme. The in vitro and in vivo release studies of ornidazole and ciprofloxacin imply that c-Dxt/pNIPAm delivers both drugs in a controlled way and would be an excellent alternative for a dual drug carrier. The FTIR, powder X-ray diffraction (XRD), and UV-vis-near infrared (NIR) spectra along with the computational study predict that the drugs remain in the matrix through physical interaction. A stability study signifies that the drugs (ornidazole ∼97% and ciprofloxacin ∼98%) are stable in the tablet formulations for up to 3 months.

Evaluation and management of diabetic and non-diabetic hypoglycemia in end-stage renal disease

Patients with end-stage renal disease (ESRD) regardless of diabetes status are at increased risk of hypoglycemia with a resultant array of adverse clinical outcomes. Therefore, hypoglycemia should be thoroughly evaluated in ESRD patients. In diabetic dialysis patients, hypoglycemic agents and nutritional alterations can trigger hypoglycemia in the background of diminished gluconeogenesis, reduced insulin clearance by the kidney and improved insulin sensitivity following initiation of renal replacement therapy. Detailed evaluation of antidiabetic regimen and nutritional patterns, patient education on self-monitoring of blood glucose and/or referral to a diabetes specialist may reduce risk of subsequent hypoglycemia. In certain situations, it is important to recognize the possibility of non-diabetic causes of hypoglycemia in patients with diabetes and to avoid treating pseudo-hyperglycemia caused by glucose- non-specific glucometers in patients utilizing icodextrin-based solutions for peritoneal dialysis. Adrenal insufficiency, certain medications, malnutrition and/or infection are among the most common causes of hypoglycemia in non-diabetic ESRD patients, and they should be suspected after exclusion of inadvertent use of hypoglycemic agents. The goal of this review article is to summarize approaches and recommendations for the work up and treatment of hypoglycemia in ESRD.

Modified biopolymer-dextrin based crosslinked hydrogels: application in controlled drug delivery

This review describes hydrogels and their classifications along with the synthesis and properties of biopolymer-dextrin based crosslinked hydrogels towards potential application in controlled drug delivery.

Effect of icodextrin on heart rate variability in diabetic patients on peritoneal dialysis

INTRODUCTION

Spectral analysis of heart rate variability is a noninvasive method for evaluating autonomic cardiovascular dysfunction under various clinical conditions, such as in dialysis patients, in whom an imbalance between the sympathetic and parasympathetic nervous system appears to be an important risk factor for sudden cardiovascular death and arrhythmia. ♢

OBJECTIVE

We compared the effect of icodextrin-based dialysis solution, an option that allows for better metabolic and fluid overload control, with that of glucose-based dialysis fluid on sympathetic and parasympathetic activity in the heart, as assessed by heart rate variability, in diabetic patients on peritoneal dialysis (PD). ♢

METHODS

This secondary analysis uses data from a randomized controlled trial in diabetic PD patients with high or high-average peritoneal transport using icodextrin-based (ICO group, n = 30) or glucose-based (GLU group, n = 29) solutions for the long dwell. All patients underwent 24-hour electrocardiographic Holter monitoring at baseline, and at 6 and 12 months of follow-up. ♢

RESULTS

We observed no significant differences between the groups in most of the variables analyzed, although values were, in general, below reference values. In the ICO group, total power and both low- and high-frequency power in normalized units increased, but the percentage of RR intervals with variation of more than 50 ms declined over time; in the GLU group, all those values declined. Plasma catecholamine levels were higher at baseline and declined over time. ♢

CONCLUSIONS

These results indicate a partial recovery of sympathetic activity in the ICO group, probably because of better extracellular fluid control and lower exposure to glucose with the use of icodextrin-based dialysis solutions.

Clinical factors associated with sodium removal in peritoneal dialysis patients

A cross-sectional study was conducted in 156 clinically-stable peritoneal dialysis patients to identify the factors associated with sodium removal. Serum biochemistry, peritoneal function (modified peritoneal equilibration test [PET]) and the adequacy of dialysis were analysed in relation to sodium removal using multivariate linear regression. Factors significantly affecting peritoneal sodium removal included infusion volume and ultrafiltration volume per 24 h, sodium dip in the first hour of PET and sodium difference between serum and fresh dialysate. Factors significantly affecting total sodium removal included ultrafiltration and urine volume per 24 h, sodium dip in the first hour of PET and sodium difference between serum and fresh dialysate. With traditional dialysate, adequate fluid removal is required to ensure sufficient sodium removal, but a low-sodium dialysate may prevent sodium retention. Sodium removal should be included in evaluation of the adequacy of dialysis.

Icodextrin increases technique survival rate in peritoneal dialysis patients with diabetic nephropathy by improving body fluid management: a randomized controlled trial

BACKGROUND AND OBJECTIVES

There are still controversies whether peritoneal dialysis (PD) with icodextrin preserves residual renal and peritoneal membrane functions in patients with diabetes. However, there are no randomized controlled and long-term clinical trials in newly started PD patients with diabetic nephropathy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Forty-one patients with diabetic nephropathy with ESRD were enrolled and randomly assigned to the glucose group (GLU) treated with 8 L of 1.5% or 2.5% glucose or an icodextrin group (ICO) treated with 1.5 or 2.0 L of 7.5% icodextrin-containing solutions. Technique failure, body fluid management, glucose and lipid metabolism, and residual renal and peritoneal functions and were evaluated over 2 years.

RESULTS

The technique survival rate was 71.4% in ICO and 45.0% in GLU, with most of the technique failure due to volume overload. ICO showed significantly better cumulative technique survival. Net ultrafiltration volume was significantly higher in ICO throughout the study period. There were no beneficial effects of icodextrin on hemoglobin A1c, glycoalbumin, and lipid profile at 24 months. Urine volume and residual renal function declined faster in ICO, but there were no significant differences between the two groups. For peritoneal function, no differences were observed in dialysis-to-plasma creatinine ratios during the observation.

CONCLUSIONS

In PD therapy for diabetic nephropathy, the use of icodextrin-containing solutions has a beneficial effect on technique survival, but there are no apparent benefits or disadvantages in residual renal and peritoneal functions compared with conventional PD with glucose solution.

False elevation of blood glucose levels measured by GDH-PQQ-based glucometers occurs during all daily dwells in peritoneal dialysis patients using icodextrin

OBJECTIVE

False elevation of blood glucose levels measured by glucose dehydrogenase pyrroloquinoline quinone (GDH-PQQ)-based glucose self-monitoring systems; glucometer) in peritoneal dialysis (PD) patients using icodextrin solution has been well documented. However, adverse hypoglycemic events caused by misreadings for blood glucose are still being reported. We aimed to study blood glucose levels measured simultaneously using different methods in PD patients with switching of icodextrin, and throughout daily exchanges either using icodextrin or not.

DESIGN

We recruited 100 PD patients, including 40 using icodextrin; 128 hemodialysis patients served as a reference. Fasting serum glucose was measured using our laboratory reference method (LAB) and 2 glucose self-monitoring systems based on glucose dehydrogenase nicotinamide adenine dinucleotide (GDH-NAD) and GDH-PQQ respectively. 80 PD patients had a second follow-up study. A time course study was performed in 16 PD patients through measuring fingertip glucose using the 2 glucose self-monitoring systems during daily exchanges.

RESULT

The differences in measured serum glucose levels in (PQQ minus LAB) versus (NAD minus LAB) were markedly increased in PD patients using icodextrin compared to other patient groups, and was further confirmed by the follow-up study in patients that switched to icodextrin. The high serum glucose levels measured by the GDH-PQQ-based glucose self-monitoring system were present throughout all exchanges during the day in patients using icodextrin solution.

CONCLUSION

False elevation of blood glucose measured by GDH-PQQ-based glucose self-monitoring systems exists in patients using icodextrin. To avoid misinterpretation of hyperglycemia and subsequent over-injection of insulin, GDH-PQQ-based glucose self-monitoring systems should not be used in PD patients.

In Vivo Biocompatibility and Biodegradability of Dextrin-based Hydrogels

The in vivo biocompatibility of dextrin hydrogels obtained by polymerization of dextrin-hydroxyethylmethacrylate (dextrin-HEMA) and dextrin-vinyl acrylate (dextrin-VA) are reported in this work. The histological analysis of subcutaneous implants of these hydrogels, featuring inflammatory and reabsorption events, were carried out over a 16-week period in mice. The dextrin-HEMA hydrogel was quickly and completely degraded and reabsorbed, whereas the dextrin-VA degradation occurred slowly and a thin fibrous capsule surrounded the nondegradable hydrogel. The dextrin-HEMA was degraded after 16 weeks with only mild inflammation and a few detectable foamy macrophages around the implant. These events were followed by complete resorption and no sign of capsule formation or fibrosis associated to the implants. The results indicate that the dextrin hydrogels are biocompatible because no toxicity on the tissues surrounding the implants was found. It may be speculated that a controlled degradation rate of the hydrogels may be obtained by grafting dextrin to HEMA and VA in different proportions.

Polymeric carriers: preclinical safety and the regulatory implications for design and development of polymer therapeutics

Since the early 1990s polymer-protein conjugates (included PEGylated enzymes and cytokines), polymeric drugs and polymeric sequestrants have been entering the market as innovative polymer-based therapeutics. Initially these products were most frequently developed as novel anticancer agents; indeed they can be considered first generation "nanomedicines". More recently, a much broader range of life-threatening and debilitating diseases (e.g. viral infections, arthritis, multiple sclerosis and hormone abnormalities) have been targeted via intravenous (i.v.), subcutaneous (s.c.) or oral routes of administration. Given the increasing novelty of polymeric materials proposed for development as second-generation polymer therapeutics (with increasing complexity of conjugate composition), and the growing debate as to the safety of nanomedicines per se, the need for evolution of an appropriate regulatory framework is at the forefront of the scientific discussion. The adequacy of the current tests and models used to define safety are also constantly being reviewed. Here we describe the current status and future challenges in relation to these issues.

Effect of icodextrin dialysis solution on body weight and fat accumulation over time in CAPD patients

BACKGROUND

The purpose of this study was to analyse the changes of body composition and the effects of icodextrin dialysis solution over time on peritoneal dialysis (PD) in continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

Among 183 incident patients, 75 patients finished a complete 36-month protocol. Clinical indices including daily glucose absorption and body composition, by bioelectrical impedance analysis (BIA), were measured in both groups (icodextrin group: 36 patients, non-icodextrin group: 39 patients) at the 1st (baseline), 12th, 24th and 36th months.

RESULTS

There were significant increases in body weight and fat mass during the 36 months after initiation of CAPD. It was found that 78% of 3 years of weight gain occurred during the first year and 88% of weight gain at the end of the first year was fat mass gain. The icodextrin group showed a significantly lower percent of fat mass during the first 36 months (P < 0.05) and also less changes in body weight, fat mass, percent (%) fat mass, visceral fat area and waist/hip ratio at 1, 2 and 3 years than the non-icodextrin group. There were no significant changes in total body water (TBW), extra cellular fluid (ECF), oedema index and lean body mass (LBM) through comparable daily and ultrafiltration volume (UFV) between the two groups during the initial 3 years. Factors associated with the higher percent of fat mass gain over time on peritoneal dialysis were age, diabetes, gender (female) and non-icodextrin group (all, P < 0.01, generalized estimating equation).

CONCLUSION

The application of icodextrin solution may be a better option to alleviate excessive fat gain over time for patients on PD.

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.