Assessment of body hydration in subjects with schistosomiasis

Total body water (TBW) was measured by deuterium oxide dilution (D2O) and predicted by bioelectric impedance analysis (BIA) (Deurenberg, Schouten, Andreoli and De Lorenzo 1993) in 21 subjects with Schistosoma mansoni infection and 17 healthy controls of similar age (32.8 +/- 13.7 years, n=38). Patients were selected to have no visible fluid retention and no cardiac or renal abnormalities. Body hydration (TBW per kg of body weight) was significantly higher in patients with schistosomiasis than in controls (62.9 +/- 3.6 vs 57.4 +/- 4.3%, p < 0.0005). A significant correlation was found between albumin levels and TBW% on the pooled sample (n=38; r=0.660, p < 0.0001). This relationship was not influenced by the presence of disease, as determined by ANCOVA. Values of TBW predicted by BIA were highly correlated and not significantly different (p=n.s., ANOVA) from those measured by D2O in both controls and patients (r=0.854, p < 0.001, SEE = 2.3 1, CV=5.9% and r=0.848, p < 0.001, SEE=4.0 1, CV=9.3%, respectively). The bias (TBW by BIA - TBW by D2O) was of 0.9 +/- 3.7 in controls and of -1.3 +/- 4.2 1 in patients. This bias was significantly correlated to TBW% in patients (r=0.575, p < 0.05) but not in controls (p=n.s.). It is concluded that subjects with schistosomiasis show an apparent subclinical increase in body hydration which could affect the prediction of TBW from BIA.