Background: At present few data are available on the total body water (TBW) content and in particular on the distribution of water in the intra- and extracellular compartments (ICW and ECW) of alcoholics. The aim of this study was to evaluate TBW, ICW, and ECW in chronic alcoholic patients.
Methods: Thirty-six alcoholics meeting DSM-III-R criteria for diagnosis (20 men, 16 women; body mass index [BMI] 22.3+/-2.57 kg/m2) were enrolled. Fifty-four healthy social drinkers (31 men, 23 women; BMI 23.7+/-1.68 kg/m2) matched for age and height were used as controls. Systolic and diastolic blood pressure was measured for all cases. All patients were assessed using specific anthropometric measurements. The waist-to-hip ratio (WHR) was used as an indicator of body fat distribution. TBW was measured by isotopic dilution by giving 100 microCi of tritiated water. ICW and ECW were assessed by multifrequence bioelectric impedance analysis (BIA). Basal metabolic rate (BMR) was measured by indirect calorimetry.
Results: Body weight was lower in the alcoholics than in the controls (61.9+/-5.5 kg vs. 65.8+/-5.2 kg;p < 0.01), essentially due to a reduction in fat mass. Significantly higher WHR values were found in both male (p < 0.001) and female (p < 0.001) alcoholics than in healthy subjects. A higher ECW/TBW ratio was found in the alcoholics compared with the controls, both as a whole (0.53+/-0.04 vs. 0.41+/-0.03; p < 0.0001) and separated by gender (p < 0.001).
Conclusions: The increased ECW could derive from an increase in cellular permeability related to endothelial damage linked to the vasoconstriction present in the alcoholics and/or to a direct toxic effect of ethanol on cellular membranes. In addition, because the high ECW volumes correlated positively with WHR in the alcoholics, a potential association of these two factors in determining an increased risk of liver disease, hypertension, and cardiovascular disease may exist. Finally, the lower TBW characteristic of women may be one of the reasons for the observed greater rate of toxic effects of ethanol that occur in women.