highly significantp < 0.001
The peritoneal membrane was easily permeable for the low-molecular-weight NT-proBNP and correlation with serum levels was highly significant ( r = 0.998, p < 0.001), while dialysate detectability and correlation with plasma concentrations were poor for both GDF-15 ( r = 0.548, p = 0.008) and for the relatively high-molecular-weight cNEP ( r = − 0.194, p = 0.134) (Fig. 1 b).