Deuterium equilibration time in infant's body water.

OBJECTIVE

Equilibration time of deuterium oxide was studied in infants with no restriction of food intake, as in field work stringent conditions have to be relaxed.

SUBJECTS

Ten children recovering from marasmatic undernutrition in an Infant Nutrition Centre (CONIN).

METHODS

Four males and six females [mean 253 +/- 38 (SD) days old] exclusively bottle-fed were administered a deuterium dose in their first morning feed and followed for a 12 day period. The intercept method was used as the reference to validate the isotope equilibration time within the body water pool calculated with the plateau method. Mean equilibration was found to be 291 +/- 78 (SD) (4.85 +/- 1.3 h).

RESULTS

Total body water (TBW) values calculated with both methods differed only by 0.6%, confirming that the deuterium oxide was homogeneously distributed within the body water pool at the plateau equilibration time (4.85 +/- 1.3 h). This period is much larger than the one commonly utilized, 120-180 min (2-3 h).

CONCLUSION

Regarding TBW measurements, the intercept method provides the same information as the plateau method. However, the intercept method seems more suitable for field studies when working conditions cannot be controlled. The plateau method can be useful for specific short studies providing a faster assessment of the body water pool in infants.