Measurement of 2H2O by IR absorbance in doubly labeled H2O studies of energy expenditure

1988 ◽  
Vol 255 (1) ◽  
pp. R174-R177 ◽  
Author(s):  
W. H. Karasov ◽  
L. R. Han ◽  
J. C. Munger
Keyword(s):  
Energy Expenditure ◽  
Linear Relationship ◽  
Water Samples ◽  
Body Water ◽  
Doubly Labeled Water ◽  
Infrared Spectrophotometry ◽  
Turnover Rates ◽  
Precision And Accuracy ◽  
Fractionation Factors

The energy expenditure of animals in their natural surroundings can be determined by measuring the turnover in body water of isotopes of oxygen and hydrogen. We evaluated the use of infrared spectrophotometry for measuring 2H2O in small (20-microliters) water samples also labeled with 18O. For 2H2O over the enrichment range of 0.1-1 atom%, there was a linear relationship between infrared absorbance and 2H2O enrichment. 2H2O enrichments could be measured with a precision and accuracy of less than or equal to 1%, using this relationship. The presence of 18O in water samples in enrichments of up to 1 atom% had no significant effect on measurement of 2H2O by infrared absorbance. We measured the simultaneous turnover rates of 2H2O and 3H in mice and turtles also labeled with 18O. Our results validated the use of infrared absorbance in doubly labeled water measures of energy expenditure and indicated that the fractionation factors in vivo for 2H2O and 3H do not differ.

scholarly journals Contribution of Dietary Composition on Water Turnover Rates in Active and Sedentary Men

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 2124
Author(s):  
Alice E. Disher ◽  
Kelly L. Stewart ◽  
Aaron J. E. Bach ◽  
Ian B. Stewart
Keyword(s):  
Energy Expenditure ◽  
Dietary Intake ◽  
Water Intake ◽  
Body Water ◽  
Activity Level ◽  
Hydration Status ◽  
Dietary Composition ◽  
Turnover Rates ◽  
Water Turnover ◽  
Fibre Intake

Body water turnover is a marker of hydration status for measuring total fluid gains and losses over a 24-h period. It can be particularly useful in predicting (and hence, managing) fluid loss in individuals to prevent potential physical, physiological and cognitive declines associated with hypohydration. There is currently limited research investigating the interrelationship of fluid balance, dietary intake and activity level when considering body water turnover. Therefore, this study investigates whether dietary composition and energy expenditure influences body water turnover. In our methodology, thirty-eight males (19 sedentary and 19 physically active) had their total body water and water turnover measured via the isotopic tracer deuterium oxide. Simultaneous tracking of dietary intake (food and fluid) is carried out via dietary recall, and energy expenditure is estimated via accelerometery. Our results show that active participants display a higher energy expenditure, water intake, carbohydrate intake and fibre intake; however, there is no difference in sodium or alcohol intake between the two groups. Relative water turnover in the active group is significantly greater than the sedentary group (Mean Difference (MD) [95% CI] = 17.55 g·kg−1·day−1 [10.90, 24.19]; p = < 0.001; g[95% CI] = 1.70 [0.98, 2.48]). A penalised linear regression provides evidence that the fibre intake (p = 0.033), water intake (p = 0.008), and activity level (p = 0.063) predict participants’ relative body water turnover (R2= 0.585). In conclusion, water turnover is faster in individuals undertaking regular exercise than in their sedentary counterparts, and is, in part, explained by the intake of water from fluid and high-moisture content foods. The nutrient analysis of the participant diets indicates that increased dietary fibre intake is also positively associated with water turnover rates. The water loss between groups also contributes to the differences observed in water turnover; this is partly related to differences in sweat output during increased energy expenditure from physical activity.

scholarly journals Use of feces to estimate isotopic abundance in doubly labeled water studies in reindeer in summer and winter

1997 ◽  
Vol 273 (4) ◽  
pp. R1451-R1456 ◽  
Author(s):  
Geir Gotaas ◽  
Eric Milne ◽  
Paul Haggarty ◽  
Nicholas J. C. Tyler
Keyword(s):  
Energy Metabolism ◽  
Energy Expenditure ◽  
Rate Constants ◽  
Total Energy Expenditure ◽  
Body Water ◽  
Doubly Labeled Water ◽  
Isotopic Abundance ◽  
Wild Mammals ◽  
Doubly Labeled Water Method ◽  
Free Ranging

The reliance on samples of blood or urine to estimate isotopic abundance in studies of energy metabolism using the doubly labeled water method has restricted application of the technique to animals that are either tame or easy to catch. This is generally not the case with large, free-ranging wild mammals. The use of feces as a source of body water in which to measure the concentration of isotopic markers was investigated in four female reindeer in summer and in winter.2H2O and H2 18O were injected to ∼160 parts per million excess. Samples of plasma and feces were then collected simultaneously for up to 456 h. Both isotopes were equilibrated with body water at 8 h postdose. There were no significant differences by animal between dilution spaces, rate constants, rates of CO2production, and total energy expenditure (TEE) calculated based on samples of plasma or feces in any trial. Mean TEE was 3.557 W/kg (SD 0.907, n = 4) in summer and 1.865 W/kg (SD 0.166, n = 4) in winter.

Effect of bolus fluid intake on energy expenditure values as determined by the doubly labeled water method

1992 ◽  
Vol 72 (1) ◽  
pp. 82-86 ◽  
Author(s):  
D. Drews ◽  
T. P. Stein
Keyword(s):  
Energy Expenditure ◽  
Fluid Intake ◽  
Accurate Method ◽  
Body Water ◽  
The Body ◽  
Doubly Labeled Water ◽  
Water Sampling ◽  
Doubly Labeled Water Method ◽  
Point Determination ◽  
Source Of Error

The doubly labeled water (DLW, 2H(2)18O) method is a highly accurate method for measuring energy expenditure (EE). A possible source of error is bolus fluid intake before body water sampling. If there is bolus fluid intake immediately before body water sampling, the saliva may reflect the ingested water disproportionately, because the ingested water may not have had time to mix fully with the body water pool. To ascertain the magnitude of this problem, EE was measured over a 5-day period by the DLW method. Six subjects were dosed with 2H2(18)O. After the reference salivas for the two-point determination were obtained, subjects drank water (700–1,000 ml), and serial saliva samples were collected for the next 3 h. Expressing the postbolus saliva enrichments as a percentage of the prebolus value, we found 1) a minimum in the saliva isotopic enrichments were reached at approximately 30 min with the minimum for 2H (95.48 +/- 0.43%) being significantly lower than the minimum for 18O (97.55 +/- 0.44, P less than 0.05) and 2) EE values calculated using the postbolus isotopic enrichments are appreciably higher (19.9 +/- 7.5%) than the prebolus reference values. In conclusion, it is not advisable to collect saliva samples for DLW measurements within approximately 1 h of bolus fluid intake.

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.

scholarly journals Doubly labelled water assessment of energy expenditure: principle, practice, and promise

2017 ◽  
Vol 117 (7) ◽  
pp. 1277-1285 ◽  
Author(s):  
Klaas R. Westerterp
Keyword(s):  
Energy Expenditure ◽  
Observation Interval ◽  
Energy Requirement ◽  
Dietary Assessment ◽  
Body Water ◽  
Assessment Methods ◽  
The Body ◽  
Turnover Rates ◽  
Doubly Labelled Water ◽  
The Difference

AbstractThe doubly labelled water method for the assessment of energy expenditure was first published in 1955, application in humans started in 1982, and it has become the gold standard for human energy requirement under daily living conditions. The method involves enriching the body water of a subject with heavy hydrogen (2H) and heavy oxygen (18O), and then determining the difference in washout kinetics between both isotopes, being a function of carbon dioxide production. In practice, subjects get a measured amount of doubly labelled water (2H 2 18 O) to increase background enrichment of body water for 18O of 2000 ppm with at least 180 ppm and background enrichment of body water for 2H of 150 ppm with 120 ppm. Subsequently, the difference between the apparent turnover rates of the hydrogen and oxygen of body water is assessed from blood-, saliva-, or urine samples, collected at the start and end of the observation interval of 1–3 weeks. Samples are analyzed for 18O and 2H with isotope ratio mass spectrometry. The doubly labelled water method is the indicated method to measure energy expenditure in any environment, especially with regard to activity energy expenditure, without interference with the behavior of the subjects. Applications include the assessment of energy requirement from total energy expenditure, validation of dietary assessment methods and validation of physical activity assessment methods with doubly labelled water measured energy expenditure as reference, and studies on body mass regulation with energy expenditure as a determinant of energy balance.

Precision and accuracy of doubly labeled water energy expenditure by multipoint and two-point methods

1992 ◽  
Vol 263 (5) ◽  
pp. E965-E973 ◽  
Author(s):  
T. J. Cole ◽  
W. A. Coward
Keyword(s):  
Energy Expenditure ◽  
Human Subjects ◽  
Carbon Dioxide Production ◽  
Doubly Labeled Water ◽  
Water Turnover ◽  
The United Kingdom ◽  
Multipoint Method ◽  
Precision And Accuracy ◽  
Using Data ◽  
Better Than

Two-point or multipoint, that is the question. Equations are developed to compare the precision and accuracy of energy expenditure, as estimated from doubly labeled water data, when analyzed by the multipoint and two-point methods. The equations convert the enrichments of deuterium and oxygen-18 into their ratio and product, quantities that are less covariant than the two isotopes themselves are. This is important not only for estimating the precision but also as a graphical aid, since the ratios of the enrichments model carbon dioxide production, whereas the enrichment products largely model water turnover. Using data on 12 human subjects from the United Kingdom and The Gambia as examples, the combined precision and accuracy of the multipoint method (CV 3.6%) was found to be appreciably better than the two-point method (CV 5.4%). The bias in the multipoint estimate of body pool size would need to be three times as large as was observed before it canceled out the better precision.

Flux hydriques et métabolisme énergétique dans un peuplement de Lacertidés des îles Kerkennah (Tunisie)

1988 ◽  
Vol 66 (3) ◽  
pp. 555-561 ◽  
Author(s):  
Roland Vernet ◽  
Claude Grenot ◽  
Saïd Nouira
Keyword(s):  
Energy Expenditure ◽  
Daily Activity ◽  
Water Flux ◽  
Sympatric Species ◽  
Doubly Labeled Water ◽  
Daily Energy Expenditure ◽  
Water Turnover ◽  
Semiarid Environment ◽  
Daily Energy ◽  
Active Forager

Water flux and daily energy expenditure were measured with doubly labeled water (3HH18O) in two insectivorous sympatric species of Lacertidae of Kerkennah islands (Tunisia), Eremias olivieri (mean body mass: 1.1 g) and Acanthodactylus pardalis (4.5 g) in a semiarid environment. Water turnover and field metabolic rate of Eremias olivieri (174 μL H2O g−1 d−1 and 250 J g−1 d−1) were, respectively, 2.5 and 5 times higher than those of Acanthodactylus pardalis (70 μL H2O g−1 d−1 and 52 J g−1 d−1). The water turnover of Eremias olivieri is one of the highest known among insectivorous lizards, and the daily energy expenditure of Acanthodactylus pardalis one of the lowest. The most plausible explanations are the differences in the size of the prey eaten by each species at this time of the season and in the duration of daily activity; the daily activity of Acanthodactylus pardalis is short (4.5 h d−1) although it is a sit-and-wait predator, whereas Eremias olivieri is active regularly every day for a longer period (7.5 h d−1) although it is an active forager. The high values of water turnover in Eremias olivieri suggest that food is not the only source of water for lizards in this particular insular environment.

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