Background: there are gaps in the knowledge of factors which influence peritoneal potassium transport in Peritoneal Dialysis (PD). The aims of this study were to compare peritoneal potassium transport in PD patients undergoing 2.27% and 3.86% peritoneal equilibration tests (PET), and to disclose clinical correlates of this phenomenon.
Method: ninety PD patients underwent 2.27% and 3.86% PET, in a random order. We compared peritoneal potassium transport in both tests, and searched for correlations between D/P potassium at 240 minutes (main study variable) and PET-derived markers of peritoneal function and selected demographic, clinical and biochemical variables, using a multivariate approach.
Main results: D/P potassium showed a good agreement between both PET, and presented a univariate association with creatinine transport, but not with plasma potassium, ultrafiltration or sodium dip. Age, PD modality, peritoneal glucose load, icodextrin, ACEI-ARA and calcium antagonist therapy, urinary potassium and glomerular filtration rate were other univariate correlates of potassium transport. Multivariate analysis confirmed D/P creatinine at 240 minutes (B=0.40 [95% CI 0.26-0.53] 2.27%, B=0.36 [0.21-0.51] 3.86%, p < 0.0005) as the main predictor of D/P potassium at 240 minutes. Urinary potassium, rather than glomerular filtration rate, sustained also an inverse correlation with the dependent variable. Treatment with ACEI-ARA was consistently associated with peritoneal potassium transport (3.86% PET B=0.08 [0.04-0.12], p < 0.0005).
Conclusions: The 2.27% and the 3.86% PET show a good agreement at the time of estimating peritoneal potassium transport. Urinary potassium excretion and treatment with ACEI-ARA (3.86% test) show an independent association with peritoneal potassium transport rates.