A number of studies have reported that icodextrin-based solution provides various clinical benefits compared with conventional glucose-based solutions (3-7). In particular, icodextrin has been successfully used in the fluid management of PD patients (4-5, 7). However, excessive ultrafiltration may induce underhydration, resulting in faster decline in residual renal function. This concern was first raised by Konings et al (8). In this study, a greater fall in residual glomerular filtration rate (GFR) was observed in patients using icodextrin compared to those using 1.36% glucose solution. In contrast, contradictory findings were also reported from the two studies indicating that residual renal function can be preserved by icodextrin solution (4, 9). Although the mechanisms are not clear, possible explanation includes the presence of high-molecular-weight icodextrin metabolites in plasma, which in turn may increase plasma oncotic pressure and hence preserve plasma volume and renal perfusion as suggested by Davies et al (10). Such discrepant findings may be explained by differences in study design, baseline fluid status, and other factors affecting residual renal function during the study. In the study by Konings et al (8), the comparative solution was 1.36% glucose, whereas 2.27% glucose was used in the study by Davies et al (4). Therefore, it can be speculated that volume status might differ depending on different concentration of glucose solution, thus leading to conflicting results. Also, these two prior studies are limited by residual renal function as secondary outcome, a short follow-up duration (4 mo vs. 6 mo), and small number of patients (32 vs. 50).