SERUM DISACCHARIDES AND OSMOLALITY IN CCPD PATIENTS USING ICODEXTRIN OR GLUCOSE AS DAYTIME DWELL

Objective: To evaluate the safety, efficacy, and biocompatibility of i codextrin- and glucose-containing dialysis fluid during continuous cyc ling peritoneal dialysis (CCPD), patients were treated for 2 years wit h either icodextrin- or glucose-containing dialysis fluid for their da ytime dwell (14 - 15 hours). Prior to entry into the study, all patien ts used a standard glucose solution (Dianeal 1.36%, 2.27%, or 3.86%, B axter, Utrecht, The Netherlands). Design: Open, randomized, prospectiv e, two-center study. Setting: University hospital and teaching hospita l. Patients: Both established and patients new to CCPD were included. A life expectancy of more than 2 years, a stable clinical condition, a nd written informed consent were necessary before entry. Patients aged under 18, those with peritonitis in the previous month, and women of childbearing potential, unless taking adequate contraceptive precautio ns, were excluded. Thirty-eight patients entered the study, and 25 (13 glucose, 12 icodextrin) had a follow-up period of 12 months or longer in December 1996. Main Outcome Measures: Serum icodextrin metabolites : one to five glucose units (G1 - G5), a high molecular weight fractio n (G > 10), and total carbohydrate level, as well as a biochemical pro file were determined every 3 months in combination with all other stud y variables. Results: In icodextrin-treated patients, serum disacchari de (maltose) concentrations increased from 0.05 +/- 0.01 (mean+/-SEM) at baseline, to an average concentration in the follow-up visits of 1. 14 +/- 0.13 mg/mL (p < 0.001). All icodextrin metabolites increased si gnificantly from baseline, as illustrated by the serum total carbohydr ate minus glucose levels: from 0.42 +/- 0.05 mg/mL to an average conce ntration in the follow-up visits of 5.04 +/- 0.49 mg/mL (p < 0.001). A t the same time, serum sodium levels decreased from 138.1 +/- 0.7 mmol /L to an average concentration in the follow-up visits of 135.4 +/- 0. 8 mmol/L (p < 0.05). However, after 12 months the serum sodium concent ration increased nonsignificantly (NS) from baseline to 136.6 +/- 0.9 mmol/L, after an initial decrease. Serum osmolality increased signific antly from baseline in icodextrin users at 9 and 12 months, but did no t differ significantly from glucose users in any visit. In icodextrin- treated patients, the calculated serum osmolal gap increased significa ntly from 4.1 +/- 1.4 mOsm/kg to an average of 11.8 +/- 1.7 mOsm/kg (p < 0.01). The sum of the serum icodextrin metabolites in millimoles/li ter equaled the increase in osmolal gap. Body weight increased in icod extrin users (71.9 +/- 2.8 kg to 77.8 +/- 3.0 kg; NS). Clinical advers e effects did not accompany these findings. Residual renal function re mained stable during follow-up. Conclusions: The serum icodextrin meta bolite levels in the present study increased markedly and were the sam e as those found previously in continuous ambulatory peritoneal dialys is patients treated with icodextrin, despite the longer dwell time for CCPD patients (14 - 16 hr versus 8 - 12 hr). The initial decrease in serum sodium concentration was followed by an increase to a concentrat ion not different from baseline at 12 months. The pathophysiology of t his finding is speculated. Calculated osmolal gap in icodextrin patien ts increased significantly (p < 0.81) at every follow-up visit, and co uld be explained by the serum icodextrin metabolite increase. We encou ntered no clinical side effects of the observed levels of icodextrin m etabolites.