Protein-calorie malnutrition is associated with poor prognosis in chronic
liver disease, but reliable assessment is hampered by changes in body water. We prospectively evaluated the effect of fluid retention on bioelectrical impedance analysis (BIA) as a simple method for the estimation of body cell mass (BCM(BIA)) in 41 patients with
cirrhosis (n = 20 with
ascites; n = 21 without
ascites) using total body
potassium counting (BCM(
TBP)) as a reference method. Arm muscle area and
creatinine-derived lean body mass were compared with total body
potassium data. In patients total body
potassium was 24.4% lower than in controls and this loss was more severe in patients with
ascites (-34.1%; P<.01). BCM(BIA) and BCM(
TBP) were closely correlated in controls (r(2) =.87, P<.0001), patients without
ascites (r(2) =.94, P <.0001) and patients with
ascites (r(2) =.56, P<.0001). Removal of 6.2 +/- 3 L of
ascites had only minor effects on BCM(BIA) (deviation of -0.18 kg/L
ascites). Limits of agreement between both methods were wider in patients with
ascites than in patients without (6.2 vs. 4.2 kg). In patients without
ascites arm muscle area (r(2) =.64; P<.001) and lean body mass (r(2) =.55; P<.001) correlated significantly with total body
potassium, but not in patients with
ascites. For assessment of
protein malnutrition in patients with
cirrhosis, body cell mass determination by use of BIA offers a considerable advantage over other widely available but less accurate methods like anthropometry or the
creatinine approach. Despite some limitations in patients with
ascites, BIA is a reliable bedside tool for the determination of body cell mass in cirrhotic patients with and without
ascites.