Comparison of the body fluid levels in healthy individuals and those with schizophrenia in Japan: using the bioelectrical impedance method.

Polydipsia and water intoxication have been found to be care problems in people with schizophrenia in many countries. This Japanese study measured the body fluid distribution and body fat of 80 males with long standing schizophrenia and compared this to that of 64 healthy males, using bioelectrical impedance spectrum analysis (BIS). Participants with schizophrenia exhibited significantly lower percentages of intracellular fluid and total body fluid, and significantly higher percentages of fat. Moreover, the percentage of extracellular fluid was distributed over a wider range. When the percentage body fluid was compared between the two groups by matching body mass index and body fat, intracellular fluid was significantly lower for those participants with schizophrenia. There findings suggest that nurses and other health professionals need to be very cautious when attempting to modify the excessive drinking of fluids by patients with schizophrenia. In mistakenly trying to prevent water intoxication, they may in fact be contributing to dehydration.