Icodextrin use for peritoneal dialysis in Australia: A cohort study using Australia and New Zealand Dialysis and Transplant Registry

BACKGROUND

Icodextrin is a high molecular weight, starch-derived glucose polymer that is used as an osmotic agent in peritoneal dialysis (PD) to promote ultrafiltration. There has been wide variation in its use across Australia and the rest of the world, but it is unclear whether these differences are due to patient- or centre-related factors.

METHODS

Using the Australia and New Zealand Dialysis and Transplant Registry, all adult patients (>18 years) who started PD in Australia between 1 January 2007 and 31 December 2014 were included. The primary outcome was icodextrin use at PD commencement. Hierarchical logistic regression clustered around the treatment centre was applied to determine the patient- and centre-related characteristics associated with icodextrin use. The impact of centre-level practice pattern variability on icodextrin uptake was estimated using the intra-cluster correlation coefficient (ICC).

RESULTS

Of 5948 patients starting on PD in 58 centres during the study period, 2002 (33.7%) received icodextrin from the outset. Overall uptake of icodextrin increased from 29% in 2010 to 42.5% in 2014. Patient-level characteristics associated with an increased likelihood of commencing PD with icodextrin included male sex (adjusted odds ratio (OR) 1.55, 95% confidence interval (CI) 1.35-1.77; p < 0.001), prior haemodialysis or kidney transplantation (OR 1.26, 95% CI 1.09-1.47), obesity (OR 1.66, 95% CI 1.41-1.96), diabetes mellitus (OR 2.32, 95% CI 2.03-2.64) and residing in a postcode with the highest decile of socio-economic status (OR 1.43, 95% CI 1.11-1.85). The centre-level characteristic associated with an increased likelihood of commencing PD with icodextrin was routine assessment of a peritoneal equilibration test (OR 1.45, 95% CI 1.27-1.66). Centres with fewer patients on automated peritoneal dialysis (APD) were less likely to start on icodextrin (APD proportion <57%; OR 0.45, 95% CI 0.20-0.99). Centre factors accounted for 25% of the variation in icodextrin use solution among incident PD patients (ICC 0.25).

CONCLUSIONS

Icodextrin use in incident Australian PD patients is increasing variable and associated with both patient and centre characteristics. Centre-related factors explained 25% of variability in icodextrin use.

Icodextrin is associated with a lower risk of atrial fibrillation in peritoneal dialysis patients

AIM

Dialysis patients with atrial fibrillation (AF) are at 1.72-fold increased mortality risk. This study investigated whether peritoneal dialysis (PD) patients using icodextrin were at a reduced risk of AF.

METHODS

From the Taiwan National Health Insurance database, we identified 4040 icodextrin users and 3517 non-users among 7557 patients newly diagnosed with end-stage renal disease undergoing PD from 2005 to 2011. The incidence of AF was compared between PD patients with and without icodextrin treatment by the end of 2011, with the hazard ratio (HR) of AF measured using Cox proportional hazards regression models.

RESULTS

The incidence of AF was 50% lower in icodextrin users than in non-users (2.14 vs 4.24 per 1000 person-years) with an adjusted HR of 0.49 (95% confidence interval (CI) = 0.28-0.85). The protective effect was greater for PD patients with diabetes (adjusted HR = 0.39, 95% CI = 0.17-0.86) than those without diabetes (adjusted HR = 0.57, 95% CI = 0.28-1.18). The beneficial effect of icodextrin treatment remained after controlling for the competing risk of deaths, with an adjusted sub-HR of 0.35 (95% CI = 0.16-0.75) for those with diabetes and 0.50 (95% CI = 0.26-0.99) for those without diabetes.

CONCLUSION

The use of icodextrin solution is associated with a lower risk of new-onset AF in PD patients. The protective effectiveness was greater for those with diabetes.

Icodextrin reduces the risk of congestive heart failure in peritoneal dialysis patients

PURPOSE

Icodextrin can enhance ultrafiltration and consequently improve fluid balance and can control blood pressure and reduce left ventricular mass for peritoneal dialysis (PD) patients. This study investigated whether icodextrin use could reduce the risk of congestive heart failure (CHF) for PD patients.

METHODS

From the Taiwan National Health Insurance database, we identified 5462 newly diagnosed end-stage renal disease patients undergoing PD from 2005 to 2010. Incidence rates and hazard ratio of CHF were estimated for patients with and without icodextrin treatment by the end of 2011.

RESULTS

Among PD patients, icodextrin users had an overall 26% lower incidence of CHF than non-users (13.7 vs 18.6 per 1000 person-years). Relatively, the adjusted hazard ratio was 0.67 (95% CI = 0.52-0.87) for users compared with non-users. Among PD patients with diabetes, the incident CHF in icodextrin users was 37.5% lower than that in non-users (17.8 vs 28.5 per 1000 person-years). Among PD patients without diabetes, the incident CHF in icodextrin users was 30.4% lower than that in non-users (11.0 vs 15.8 per 1000 person-years).

CONCLUSIONS

Icodextrin solution could reduce the risk of new-onset CHF, particularly effective when diabetic PD patients use it.

PATHOPHYSIOLOGY AND MANAGEMENT OF HYPOGLYCEMIAIN END-STAGE RENAL DISEASE PATIENTS: A REVIEW

OBJECTIVE

This review focuses on hypoglycemia in patients with end-stage renal disease (ESRD). It discusses the pathophysiology of glucose metabolism in the kidney, the impact of dialysis on glucose and insulin metabolism, and the challenges of glucose monitoring in ESRD. The clinical relevance of these changes is reviewed in relation to altered blood glucose targets and modification of antidiabetes therapy to prevent hypoglycemia. Based on current data and guidelines, recommendations for the outpatient and inpatient setting are provided for diabetes management in ESRD.

METHODS

PubMed, OVID, and Google Scholar were searched to identify related articles through May 2016 using the following keywords: "glucose metabolism," "kidney," "diabetes," "hypoglycemia," "ESRD," and "insulin" in various combinations for this review.

RESULTS

In ESRD, a combination of impaired insulin clearance, changes in glucose metabolism, and the dialysis process make patients vulnerable to low blood glucose levels. Hypoglycemia accounts for up to 3.6% of all ESRD-related admissions. At admission or during hospitalization, hypoglycemia in ESRD has a poor prognosis, with mortality rates reported at 30%. Several guidelines suggest a modified hemoglobin A1c (A1c) goal of 7 to 8.5% (53 to 69 mmol/mol) and an average blood glucose goal of 150 to 200 mg/dL. Noninsulin antidiabetes agents like dipeptidyl peptidase 4 inhibitors, repaglinide, and glipizide in appropriate doses and reduction of insulin doses up to 50% may help decrease hypoglycemia.

CONCLUSION

Patients with ESRD are at high risk for hypoglycemia. Increased awareness by providers regarding these risks and appropriate diabetes regimen adjustments can help minimize hypoglycemic events.

ABBREVIATIONS

ADA = antidiabetes agent BG = blood glucose CKD = chronic kidney disease DPP-4 = dipeptidyl peptidase 4 eGFR = estimated glomerular filtration rate ESRD = end-stage renal disease GFR = glomerular filtration rate HD = hemodialysis NPH = neutral protamine Hagedorn PD = peritoneal dialysis SA = short acting SU = sulfonylurea.

Low-Polydispersity Glucose Polymers as Osmotic Agents for Peritoneal Dialysis

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BACKGROUND

Peritoneal dialysis (PD) solutions containing icodextrin as the osmotic agent have advantages during long dwells. The glucose polymers that constitute icodextrin are a heterogeneous mix of molecules with a polydispersity [ratio of weight-average to number-average molecular weight (Mw/Mn)] of approximately 2.6. The present study evaluates whether modifications in the polydispersity and concentration of glucose polymers can improve ultrafiltration (UF) without an associated increase in carbohydrate absorption (CA). ♦

METHODS

Computer simulations using a three-pore model of peritoneal transport during a long dwell in PD patients predict that, in general, compared with 7.5% icodextrin, glucose polymers with a Mw greater than or equal to 7.5 kDa, a polydispersity less than 2.6, and concentrations greater than 7% could achieve higher UF without higher CA. Based on the simulations, we hypothesized that, compared with 7.5% icodextrin, glucose polymers with a Mw of 18 - 19 kDa and a polydispersity of 2.0 at 11% concentration could achieve higher UF without a higher CA. We tested this hypothesis in experimental studies using 8-hour dwells in New Zealand White rabbits. In those studies, UF was measured by complete fluid collection, and CA was measured by subtracting the total carbohydrate in the collected fluid from the carbohydrate initially infused. ♦

RESULTS

The UF was higher with 11% 19 kDa glucose polymer than with 7.5% icodextrin (mean ± standard deviation: 89 ± 31 mL vs 49 ± 15 mL; p = 0.004) without higher CA (5.2 ± 0.9 g vs 5.0 ± 0.9 g, p = 0.7). Similar results were seen with the 11% 18 kDa glucose polymer, which, compared with 7.5% icodextrin, resulted in higher UF (mean ± standard deviation: 96 ± 18 mL vs 66 ± 17 mL; p < 0.001) without higher CA (4.8 ± 0.7 g vs 5.2 ± 0.6 g, p = 0.2). ♦

CONCLUSIONS

The findings demonstrate that, compared with 7.5% icodextrin solution, long-dwell PD solutions containing 11% glucose polymers with a Mw of 18-19 kDa and a polydispersity of 2.0 can provide higher UF without higher CA.

Bimodal solutions or twice-daily icodextrin to enhance ultrafiltration in peritoneal dialysis patients

The efficacy and safety of icodextrin has been well established. In this paper, we will discuss the pharmacokinetics and biocompatibility of icodextrin and its clinical effect on fluid management in peritoneal dialysis patients. Novel strategies for its prescription for peritoneal dialysis patients with inadequate ultrafiltration are reviewed.

Ultrafiltration characteristics of glucose polymers with low polydispersity

BACKGROUND

Icodextrin, a glucose polymer with a polydispersity [ratio of weight-average molecular weight (Mw) to number-average molecular weight] of approximately 2.6, has been shown, compared with glucose, to provide superior ultrafiltration (UF) efficiency [ratio of UF to carbohydrate (CHO) absorbed] when used as an osmotic agent during a long-dwell peritoneal dialysis exchange. In an experimental rabbit model, we evaluated the effect of Mw on the UF and UF efficiency of glucose polymers with low polydispersity.

METHODS

A crossover trial in female New Zealand White rabbits (2.20 - 2.65 kg) with surgically implanted peritoneal catheters evaluated two glucose polymers at nominal concentrations of 7.5 g/dL: a 6K polymer (Mw: 6.4 kDa; polydispersity: 2.3) and a 19K polymer (Mw: 18.8 kDa; polydispersity: 2.0). Rabbits were randomized to receive either the 6K (n = 11) or the 19K (n = 12) solution during the first exchange (40 mL/kg body weight). The alternative solution was evaluated in a second exchange 3 days later. During each 4-hour dwell, the UF and total glucose polymer CHO absorbed were determined.

RESULTS

The UF was higher for the 6K (p < 0.0001) than for the 19K polymer (mean ± standard deviation: 73.6 ± 30.8 mL vs. 43.0 ± 20.2 mL), as was the amount of CHO absorbed (42.5% ± 9.8% vs. 35.7% ± 11.0%, p = 0.021). In spite of higher CHO absorption, an approximately 50% higher (p = 0.029) UF efficiency was achieved with the 6K polymer (28.3 ± 18.8 mL/g) than with the 19K polymer (19.0 ± 11.3 mL/g). The results were independent of the order of the experimental exchanges.

CONCLUSIONS

Glucose polymers with low polydispersity are effective osmotic agents in a rabbit model. The low-Mw polymer was more effective at generating UF and had a higher UF efficiency, but those results came at the expense of the polymer being more readily absorbed from the peritoneal cavity.