The optimal ratio of extracellular water to total body water (ECW/TBW) determined by bioelectrical impedance analysis (BIA) for setting dry weight in hemodialysis patients

Recently, we have reported that bioelectrical impedance analysis (BIA) using a body composition analyzer (InBody S20) is useful for assessing the body fluid components of hemodialysis patients. The ratio of extracellular water (ECW) to total body water (TBW) appears to be a useful marker for estimating clinical dry weight (Cl-DW). The present study investigated the optimal ECW/TBW ratio for setting DW under various clinical conditions such as diabetes, heart failure, hypoalbuminemia, dialysis-related hypotension, obesity, long-term dialysis, and non-oliguric HD patients. The subjects comprised 57 patients who were undergoing maintenance dialysis. In addition to routine blood test, various body fluid components using an InBody S20 were measured before and after dialysis. Furthermore, we measured the cardiothoracic ratio (CTR) on chest Xp, and human atrial natriuretic peptide (hANP), brain natriuretic peptide (BNP), the inferior vena cava (IVC) diameter and the left ventricular ejection fraction (EF) on cardiac ultrasonography after dialysis. The ECW/TBW ratio significantly decreased after dialysis under all clinical conditions (p