In the study by Davison et al, transport status explained only 1.6% of the variation in volume status. It can be hypothesized that fluid overload is induced by not adapting the dwell time appropriately to the transport status of the patient. Although it has been stated that removal of salt can be impaired in patients on APD, hydration status in patients on APD and CAPD was comparable in the multivariate analysis in the EuroBCM cohort, just as in previous observations. Of note, in one of these studies, the number of cycles per night was limited, so the dwell time was probably long enough to allow diffusive sodium transport. To maintain fluid balance, fast transporters need short dwells, to avoid negative ultrafiltration, and implementing APD might be of value in this patient category. On the other hand, slow transporters need long dwells to avoid sodium sieving, and APD with short cycles might be detrimental in this patient group. Johnson et al recently reported that APD was associated with better survival in fast, but with worse survival in low transporters, an observation that is compatible with this paradigm. As Davison et al, we found a negative association between serum albumin and overhydration. As this is a cross-sectional cohort, it is however impossible to determine whether low albumin is a consequence or a cause of overhydration. In the EuroBCM study cohort, polyglucose use was associated with less overhydration and more underhydration in some countries, whereas the opposite was true in other countries, pointing to PF-4217903 potential underlying differences in practice related to the use of polyglucose. In a subcohort of the EuroBCM trial, excluding countries were alternative PD solutions and APD are not liberally available due to logistical reasons, we observed a neutral impact both of the solution type and the PD modality on fluid overload, just as it was found in the cohort of Davison et al. This study is a cross sectional study, and as such, no causal relations can be drawn. However, our observations can generate some interesting hypotheses on the association between practices and hydration status. It would be interesting e.g. to study the impact on hydration status and residual renal function using a prospective protocol where implementation of polyglucose, dwell length and use of APD vs CAPD is guided by BCM based assessment of fluid overload. Another limitation is the rather crude evaluation of fluid output using patient charts as a reference, which might induce inaccuracies. However, this is the way fluid output is measured in real life. Of special interest for a future prospective study in this regard is the potential impact of bag overfill on the overestimation of ultrafiltration and fluid overload. It can be that the overestimation of real ultrafiltration by neglecting overfill can lead to overhydration, as it gives the patient and the physician the false feeling of adequate ultrafiltration.