The role of technology in the past and future development of the doubly labelled water method

19Citations
Citations of this article
21Readers
Mendeley users who have this article in their library.
Get full text

Abstract

The doubly labelled water method is an isotope-based technique that is used to measure the energy demands of free-living animals and humans. It is based on the observation that, in the body, the oxygen in carbon dioxide is in complete isotope exchange equilibrium with the oxygen in body water. Hence, a label of isotopic oxygen in body water is eliminated by both respiratory CO2 and water turnover, whereas a similarly introduced label of deuterium is eliminated only by water flux. The difference in isotope fluxes therefore permits estimation of CO2 production, which is correlated to energy demands. The doubly labelled water method has been advanced predominantly by technological advances in mass spectrometry. Although it was first described in the 1950s, it was only used on small animals and in low numbers because the costs of the isotopes were a primary constraint. However, advances in mass spectrometry precision and accuracy in the 1980s made it possible to reduce the quantities of isotope used, and hence apply the method on humans, although still in small numbers. The advent of continuous flow inlets in the 1990s made possible the processing of samples in much larger numbers and the sample sizes of studies have expanded. Ironically, however, the technique is now under treat because of technological advances in another area (positron emission tomography), which has generated an enormous demand for 18O and pushed up the price of isotopes. A continuation of this trend might drive prices to levels where sustained application of the method in human studies is questionable. Replacing determination of isotope enrichments currently performed by isotope ratio mass spectrometry with determinations made by stable isotope infrared laser spectrometry may be a technological advance that will get us out of this problem. © 2005 Taylor & Francis.

Cite

CITATION STYLE

APA

Speakman, J. R. (2005). The role of technology in the past and future development of the doubly labelled water method. Isotopes in Environmental and Health Studies, 41(4), 335–343. https://doi.org/10.1080/10256010500384283

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free