NPPB and hydrops fetalis: The association of BMI and NT-proBNP was partially mediated by DWS (mediation effect: 0.0028; 95% CI: 0.0006-0.0055) but not SWS (mediation effect: -0.0006; 95% CI: -0.0032 to 0.0015).<h4>Conclusions</h4>Among older adults without HF, BMI positively associates with DWS, and DWS positively relates with NT-proBNP, which does not account for the net inverse relationship between BMI and NT-proBNP.