Implications of the variability in time to isotopic equilibrium in the deuterium dilution technique.
Eur J Clin Nutr
; 61(11): 1250-5, 2007 Nov.
Article
en En
| MEDLINE
| ID: mdl-17299481
OBJECTIVE: To investigate the variability in isotopic equilibrium time under field conditions, and the impact of this variability on estimates of total body water (TBW) and body composition. DESIGN AND SETTING: Following collection of a fasting baseline urine sample, 10 women and 10 men were dosed with deuterium oxide (0.05 g/kg body weight). Urine samples were collected every hour for 8 h. The samples were analysed using isotope ratio mass spectrometry. Time to equilibration was determined using three commonly employed data analysis approaches. RESULTS: Isotopic equilibrium was reached by 50, 80 and 100% of participants at 4, 6 and 8 h, respectively. The mean group equilibration determined using the three different plateau determination methods were 4.8+/-1.5, 3.8+/-0.8 and 4.9+/-1.4 h. Isotopic enrichment, TBW, and percent body fat estimates differed between early (3-5 h), but not later sampling times (5-8 h). CONCLUSION: Although the three different plateau determination approaches resulted in differences in equilibration time, all suggest that sampling at 6 h or later will decrease the likelihood of error in body composition estimates resultant from incomplete isotopic equilibration in a small proportion of individuals.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Composición Corporal
/
Agua Corporal
/
Técnica de Dilución de Radioisótopos
/
Deuterio
Tipo de estudio:
Diagnostic_studies
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Eur J Clin Nutr
Asunto de la revista:
CIENCIAS DA NUTRICAO
Año:
2007
Tipo del documento:
Article
País de afiliación:
Australia
Pais de publicación:
Reino Unido