Method and rationale for recalculating dilution spaces to a single, common time point in doubly labeled water studies

Abstract

Background

The doubly labeled water (DLW) method has become widely used in studies of energy expenditure and body composition. Researchers differ in the analytical methods used to calculate the dilution spaces for deuterium and oxygen-18. Some determine dilution spaces using isotope enrichments extrapolated to the instant of dosing with DLW (slope-intercept method), but others use measured enrichments from body water samples obtained 3–10 h after dosing (plateau method). These differences limit the comparability of analyses across labs.

Methods

I derive a simple mathematical approach for recalculating reported dilution spaces to any time point post dosing, using reported dilution spaces and rates of isotope depletion. Simulated data are used to examine the effects of different dilution space protocols.

Results

Recalculating dilution spaces enables researchers to determine outcome variables of interest (e.g., total body water, energy expenditure, and water throughput) from different labs under a unified protocol for determining dilution spaces, and improves comparisons among studies.

Conclusions

Differences between dilution space protocols can lead to substantial differences in outcome variables of interest in DLW studies. When comparing results of DLW studies that employ different dilution space protocols, dilution spaces should be recalculated for a common time point, and outcome variables recalculated as needed, prior to comparison across studies.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1
Fig. 2

References

  1. 1.

    Schoeller DA. Measurement of energy expenditure in free-living humans by using doubly labeled water. J Nutr. 1988;118:1278–89.

    CAS  Article  PubMed  Google Scholar 

  2. 2.

    Speakman JR. Doubly labelled water: theory and practice. London: Chapman and Hall; 1997.

    Google Scholar 

  3. 3.

    Westerterp KR, Wouters L, van Marken Lichtenbelt WD. The Maastricht protocol for the measurement of body composition and energy expenditure with labeled water. Obes Res. 1995;Suppl 1:49–57.

    Article  Google Scholar 

  4. 4.

    Wong WW, Roberts SB, Racette SB, Das SK, Redman LM, Rochon J, et al. The doubly labeled water method produces highly reproducible longitudinal results in nutrition studies. J Nutr. 2014;144:777–83.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  5. 5.

    International Atomic Energy Agency. IAEA human health series no. 3. Assessment of body composition and total energy expenditure in humans using stable isotope techniques. Vienna: IAEA; 2009.

    Google Scholar 

  6. 6.

    Roberts SB, Dietz W, Sharp T, Dallal GE, Hill JO. Multiple laboratory comparison of the doubly labeled water technique. Obes Res. 1995;Suppl 1:3–13.

    Article  Google Scholar 

Download references

Acknowledgements

The author thanks John Speakman for helpful discussions on this topic.

Funding

This work was supported by Hunter College and Duke University.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Herman Pontzer.

Ethics declarations

Conflict of interest

The author declares that he has no conflict of interest.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Pontzer, H. Method and rationale for recalculating dilution spaces to a single, common time point in doubly labeled water studies. Eur J Clin Nutr 72, 1620–1624 (2018). https://doi.org/10.1038/s41430-018-0361-1

Download citation

Further reading

Search