Energy expenditure by doubly labeled water: validation in humans and proposed calculation

1986 ◽  
Vol 250 (5) ◽  
pp. R823-R830 ◽  
Author(s):  
D. A. Schoeller ◽  
E. Ravussin ◽  
Y. Schutz ◽  
K. J. Acheson ◽  
P. Baertschi ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Isotope Dilution ◽  
Isotope Ratio Mass Spectrometry ◽  
Co2 Production ◽  
Doubly Labeled Water ◽  
Adult Males ◽  
Doubly Labeled Water Method ◽  
The Difference ◽  
Total Body ◽  
Atom Percent Excess

To further validate the doubly labeled water method for measurement of CO2 production and energy expenditure in humans, we compared it with near-continuous respiratory gas exchange in nine healthy young adult males. Subjects were housed in a respiratory chamber for 4 days. Each received 2H2(18)O at either a low (n = 6) or a moderate (n = 3) isotope dose. Low and moderate doses produced initial 2H enrichments of 5 and 10 X 10(-3) atom percent excess, respectively, and initial 18O enrichments of 2 and 2.5 X 10(-2) atom percent excess, respectively. Total body water was calculated from isotope dilution in saliva collected at 4 and 5 h after the dose. CO2 production was calculated by the two-point method using the isotopic enrichments of urines collected just before each subject entered and left the chamber. Isotope enrichments relative to predose samples were measured by isotope ratio mass spectrometry. At low isotope dose, doubly labeled water overestimated average daily energy expenditure by 8 +/- 9% (SD) (range -7 to 22%). At moderate dose the difference was reduced to +4 +/- 5% (range 0-9%). The isotope elimination curves for 2H and 18O from serial urines collected from one of the subjects showed expected diurnal variations but were otherwise quite smooth. The overestimate may be due to approximations in the corrections for isotope fractionation and isotope dilution. An alternative approach to the corrections is presented that reduces the overestimate to 1%.

Revision of calculations in the doubly labeled water method for measurement of energy expenditure in humans

1994 ◽  
Vol 267 (6) ◽  
pp. E805-E807 ◽  
Author(s):  
W. A. Coward ◽  
P. Ritz ◽  
T. J. Cole
Keyword(s):  
Experimental Study ◽  
Energy Expenditure ◽  
Recent Work ◽  
Isotope Dilution ◽  
Rate Constants ◽  
Isotope Fractionation ◽  
Co2 Production ◽  
Doubly Labeled Water ◽  
Doubly Labeled Water Method ◽  
The Difference

In the doubly labeled water (DLW) method for the measurement of energy expenditure in humans, the basis of the calculation for CO2 production is the difference between the products of the rate constants for the disappearance of 18O and 2H from body water (KO, and KD, respectively) and the matching isotope dilution spaces (NO and ND, respectively). Thus, omitting corrections for isotope fractionation, CO2 production = 0.5 (KONO-KDND). In this calculation, it is also customary to normalize observed NO and ND values to a fixed value for ND/NO. The increasing use of the method has resulted in the generation of substantially more information on the normal value for ND/NO than existed at the time the method was first developed, and recent work has suggested that revisions of the originally used value of 1.03 may now be deemed appropriate. Values of 1.034 or 1.0427 have recently been suggested, but when applied in energy expenditure studies these estimates would lead to significantly different expenditure measurements. It can, however, be shown from published work and direct experimental study that ND/NO values are method dependent, and for these reasons the lower revised value of 1.034 appears to be more acceptable. The possibility that particular populations may ultimately be shown to be different from 1.034 should not, however, be dismissed entirely, and for this reason we suggest that information derived in individual experiments could be used in a Bayesian fashion to generate new ND/NO estimates. The appropriate techniques are described.

Use of the doubly labeled water method for measurement of energy expenditure, total body water, water intake, and metabolizable energy intake in humans and small animals

1989 ◽  
Vol 67 (10) ◽  
pp. 1190-1198 ◽  
Author(s):  
S. B. Roberts
Keyword(s):  
Energy Expenditure ◽  
Water Intake ◽  
Carbon Dioxide Production ◽  
Body Water ◽  
Metabolizable Energy ◽  
Small Animals ◽  
Doubly Labeled Water ◽  
Doubly Labeled Water Method ◽  
Metabolizable Energy Intake ◽  
Total Body

The basis of the doubly labeled water method is measurement of the differential rates of disappearance of two isotopes of water (H218O and either 2H2O or 3H2O, administered at the start of the study) from body water. Published studies indicate that, in its current forms, this technique can be used to provide accurate and reasonably precise information on carbon dioxide production, total body water, and water intake in free-living humans and many small animals. Total energy expenditure can be calculated from carbon dioxide production with little loss of precision. Metabolizable energy intake can also be predicted, as the sum of total energy expenditure plus an estimate for the change in body energy stores during the measurement, but this prediction is unlikely to be accurate and precise unless the subject is in approximate energy balance.Key words: doubly labeled water, energy metabolism, energy expenditure, water intake, body composition.

Measurement of energy expenditure in humans by doubly labeled water method

1982 ◽  
Vol 53 (4) ◽  
pp. 955-959 ◽  
Author(s):  
D. A. Schoeller ◽  
E. van Santen
Keyword(s):  
Energy Expenditure ◽  
Coefficient Of Variation ◽  
Body Water ◽  
Ratio Analysis ◽  
Doubly Labeled Water ◽  
Water Output ◽  
Isotope Ratio Analysis ◽  
Doubly Labeled Water Method ◽  
Total Body

The utility of the doubly labeled water method for the determination of energy expenditure and water output was investigated in humans. Approximately 10 g of 18O and 0.5 g of 2H as water was orally administered to four healthy adults. Total body water was determined from the isotope dilution, and the ensuing 18O and 2H disappearance rates from body water were determined for 13 days by mass spectrometric isotope ratio analysis of the urinary water. During this period, subjects were maintained on a measured diet to determine energy and water intake. The energy expenditure from the doubly labeled water method differed from dietary intake plus change in body composition by an average of 2%, with a coefficient of variation of 6%. The water outputs determined by the two methods differed by 1%, with a coefficient of variation of 7%. The doubly labeled water method is noninvasive, and the subjects could maintain their daily activities without restriction.

Sensitivity of methods for calculating energy expenditure by use of doubly labeled water

1989 ◽  
Vol 66 (2) ◽  
pp. 644-652 ◽  
Author(s):  
J. Seale ◽  
C. Miles ◽  
C. E. Bodwell
Keyword(s):  
Energy Expenditure ◽  
Weight Maintenance ◽  
Carbon Dioxide Production ◽  
Metabolizable Energy ◽  
Doubly Labeled Water ◽  
Calculation Methods ◽  
Data Set ◽  
Calculated Energy ◽  
Doubly Labeled Water Method ◽  
The Difference

Attempts to estimate human energy expenditure by use of doubly labeled water have produced three methods currently used for calculating carbon dioxide production from isotope disappearance data: 1) the two-point method, 2) the regression method, and 3) the integration method. An ideal data set was used to determine the error produced in the calculated energy expenditure for each method when specific variables were perturbed. The analysis indicates that some of the calculation methods are more susceptible to perturbations in certain variables than others. Results from an experiment on one adult human subject are used to illustrate the potential for error in actual data. Samples of second void urine, 24-h urine, and breath collected every other day for 21 days are used to calculate the average daily energy expenditure by three calculation methods. The difference between calculated energy expenditure and metabolizable energy on a weight-maintenance diet is used to estimate the error associated with the doubly labeled water method.

Validation of doubly labeled water method using a ruminant

1986 ◽  
Vol 251 (1) ◽  
pp. R143-R149 ◽  
Author(s):  
S. G. Fancy ◽  
J. M. Blanchard ◽  
D. F. Holleman ◽  
K. J. Kokjer ◽  
R. G. White
Keyword(s):  
Growth Rates ◽  
Total Body Water ◽  
Rangifer Tarandus ◽  
Accurate Method ◽  
Open Circuit ◽  
Co2 Production ◽  
Doubly Labeled Water ◽  
Doubly Labeled Water Method ◽  
Water Volumes ◽  
Total Body

CO2 production (CDP, ml CO2 . g-1 . h-1) by captive caribou and reindeer (Rangifer tarandus) was measured using the doubly labeled water method (3H2O and H2(18)O) and compared with CO2 expiration rates (VCO2), adjusted for CO2 losses in CH4 and urine, as determined by open-circuit respirometry. CDP calculated from samples of blood or urine from a reindeer in winter was 1-3% higher than the adjusted VCO2. Differences between values derived by the two methods of 5-20% were found in summer trials with caribou. None of these differences were statistically significant (P greater than 0.05). Differences in summer could in part be explained by the net deposition of 3H, 18O, and unlabeled CO2 in antlers and other growing tissues. Total body water volumes calculated from 3H2O dilution were up to 15% higher than those calculated from H2(18)O dilution. The doubly labeled water method appears to be a reasonably accurate method for measuring CDP by caribou and reindeer in winter when growth rates are low, but the method may overestimate CDP by rapidly growing and/or fattening animals.

Relative dilution spaces of 2H- and 18O-labeled water in humans

1994 ◽  
Vol 267 (4) ◽  
pp. E585-E590 ◽  
Author(s):  
S. B. Racette ◽  
D. A. Schoeller ◽  
A. H. Luke ◽  
K. Shay ◽  
J. Hnilicka ◽  
...  
Keyword(s):  
Gender Difference ◽  
Energy Expenditure ◽  
Isotope Dilution ◽  
Doubly Labeled Water ◽  
Future Studies ◽  
Average Ratio ◽  
18O Isotope ◽  
Doubly Labeled Water Method ◽  
Improved Accuracy ◽  
Space Ratio

The doubly labeled water method for measuring energy expenditure can be very sensitive to small differences in the ratio of the 2H to 18O isotope dilution spaces. Recently it has been suggested that the average ratio is higher than the 1.03 we previously recommended. We therefore combined the data from 99 recently studied subjects. Subjects (85 females and 14 males) were between the ages of 4 and 78 yr (mean = 34 yr) and between 10 and 52% (mean = 35%) fat. The average 2H-to-18O dilution space ratio was 1.034 +/- 0.014, which was very similar to the original assumption. As in recent reports, we did find that most of the variance (60%) was due to random analytic error and that there was no correlation between the dilution space ratio and age or body fat. However, in contrast to recent reports we found no evidence of a gender difference. Use of the constant dilution space ratio of 1.034 to recalculate CO2 product in published validation studies demonstrated improved accuracy, and thus the value of 1.034 is suggested for use in future studies.

Validation of single-sample doubly labeled water method

1989 ◽  
Vol 256 (2) ◽  
pp. R572-R576 ◽  
Author(s):  
M. D. Webster ◽  
W. W. Weathers
Keyword(s):  
Water Flux ◽  
Passerine Bird ◽  
Single Sample ◽  
Co2 Production ◽  
Doubly Labeled Water ◽  
Water Turnover ◽  
Sample Technique ◽  
Doubly Labeled Water Method ◽  
The One ◽  
Sample Method

We have experimentally validated a single-sample variant of the doubly labeled water method for measuring metabolic rate and water turnover in a very small passerine bird, the verdin (Auriparus flaviceps). We measured CO2 production using the Haldane gravimetric technique and compared these values with estimates derived from isotopic data. Doubly labeled water results based on the one-sample calculations differed from Haldane values by less than 0.5% on average (range -8.3 to 11.2%, n = 9). Water flux computed by the single-sample method differed by -1.5% on average from results for the same birds based on the standard, two-sample technique (range -13.7 to 2.0%, n = 9).

Longitudinal assessment of energy expenditure in pregnancy by the doubly labeled water method

1993 ◽  
Vol 57 (4) ◽  
pp. 494-505 ◽  
Author(s):  
G R Goldberg ◽  
A M Prentice ◽  
W A Coward ◽  
H L Davies ◽  
P R Murgatroyd ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Doubly Labeled Water ◽  
Longitudinal Assessment ◽  
Doubly Labeled Water Method ◽  
In Pregnancy
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