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Experimental reliability of the doubly labeled water technique
M I Goran1, E T Poehlman, E Danforth
1Department of Medicine, University of Vermont, Burlington 05405.
The American Journal of Physiology
|March 11, 1994
Summary
The doubly labeled water (DLW) technique reliably measures CO2 production rates, with experimental variation around 8.5%. This method
Area of Science:
- Human Physiology
- Metabolic Research
Background:
- The doubly labeled water (DLW) technique is a gold standard for measuring energy expenditure.
- Accurate measurement of carbon dioxide production rates (rCO2) is crucial for metabolic studies.
Purpose of the Study:
- To assess the experimental reliability of the DLW technique for measuring rCO2.
- To evaluate the impact of different calculation models on rCO2 estimates.
Main Methods:
- Five healthy young men were studied under controlled sedentary conditions and fixed energy intake.
- rCO2 was measured in duplicate over two 9-day periods using deuterium and oxygen-18.
- Turnover rates and dilution spaces were determined using multipoint sampling and both intercept and plateau methods.
Main Results:
- The average experimental variation for rCO2 estimates was approximately +/- 8.5%.
- No significant differences in variation were found among three different calculation models.
- Experimental reliability exceeded theoretical values derived from analytical uncertainty.
Conclusions:
- The DLW technique demonstrates high experimental reliability for measuring rCO2.
- The chosen calculation model for DLW does not significantly impact rCO2 measurement reliability.
- Between-subject variation in rCO2 estimates warrants consideration in study design.