Energy equivalents of CO2 and their importance in assessing energy expenditure when using tracer techniques

1991 ◽  
Vol 260 (1) ◽  
pp. E75-E88 ◽  
Author(s):  
M. Elia
Keyword(s):  
Energy Expenditure ◽  
Carbon Dioxide Production ◽  
Substantial Effect ◽  
Co2 Production ◽  
Clinical State ◽  
Free Living ◽  
Theoretical Concepts ◽  
Tracer Techniques ◽  
Different Populations ◽  
Practical Recommendations

Carbon dioxide production in free living animals and humans can be measured using tracer techniques, but the prediction of energy expenditure also requires an estimate of the energy equivalents of CO2 (energy expended/CO2 produced; EeqCO2). This work is concerned with assessing the variation in EeqCO2 with the use of dietary information, indirect calorimetry, and theoretical concepts. The EeqCO2 for diets (EeqCO2 diet) ingested by 63 individuals living in a Cambridgeshire village, UK, was found to vary by less than 10%. The EeqCO2 diet for different populations varied by greater than 10% and for artificial enteral feeds by approximately 20%. Alcohol increases this variability because it has a particularly high EeqCO2. Variation in the nitrogenous end products of metabolism may also have a substantial effect on the EeqCO2 for a subject (EeqCO2 body), especially when a large proportion of energy expenditure is derived from protein oxidation, as in strict carnivores. Nutrient/energy imbalances such as those associated with growth, hypercaloric feeding, or starvation may also have major effects on EeqCO2 body. It is concluded that the calculation of energy expenditure from CO2 production should not employ a universal value for EeqCO2 body. The value should take into account the physiological and clinical state under investigation. Practical recommendations are suggested.

scholarly journals Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 211 ◽  
Author(s):  
Geir Gotaas ◽  
Eric Milne ◽  
Paul Haggarty ◽  
Nicholas J.C. Tyler
Keyword(s):  
Energy Expenditure ◽  
Rangifer Tarandus ◽  
Water Flux ◽  
Co2 Production ◽  
Wild Ungulates ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Svalbard Reindeer ◽  
Mountain Pasture ◽  
The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69°20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

Effect of fasting and feeding on measurement of carbon dioxide production using doubly labeled water

1993 ◽  
Vol 74 (4) ◽  
pp. 1824-1829 ◽  
Author(s):  
C. M. Calazel ◽  
V. R. Young ◽  
W. J. Evans ◽  
S. B. Roberts
Keyword(s):  
Human Subjects ◽  
Carbon Dioxide Production ◽  
Co2 Production ◽  
Doubly Labeled Water ◽  
Prolonged Fasting ◽  
Free Living ◽  
Noninvasive Technique ◽  
Significant Difference ◽  
Before And After ◽  
Doubly Labeled Water Method

The doubly labeled water method is a noninvasive technique for measurement of rates of CO2 production and total energy expenditure in free-living human subjects. The experimental protocol used in validation studies usually involves prolonged fasting before and after the isotope dose is given to start the study, although it is not clear whether this intrusive aspect of the method is necessary. We investigated this issue in four healthy adults [3 women and 1 man: age 29 +/- 2 (SD) yr, body mass index 22 +/- 2.7 kg.m2] with monitored constant physical activity who underwent two doubly labeled water studies that differed only in the duration of fasting before and after isotope dosing (either 6 h of fasting before and 5 h after dosing or 0.5 h before and 3 h afterward). No significant difference between the two measurements was found in the rate constants for isotope disappearance, the ratio of the dilution spaces of the isotopes, or CO2 production rate. These results indicate that prolonged fasting before and after isotope administration should not be necessary in doubly labeled water studies.

scholarly journals Energy expenditure in disease: time to revisit?

2000 ◽  
Vol 59 (2) ◽  
pp. 199-207 ◽  
Author(s):  
Eileen R. Gibney
Keyword(s):  
Energy Expenditure ◽  
Total Energy ◽  
Energy Requirement ◽  
Total Energy Expenditure ◽  
Energy Requirements ◽  
Direct Result ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Tracer Techniques ◽  
Urea Method

Knowledge of energy expenditure is especially important in disease, and may in fact help in the understanding of the pathophysiology of wasting associated with disease. Energy requirements in a clinical setting are often ‘prescribed’ by health professionals, either directly through enteral or parenteral feeding, or perhaps controlled through a hospital diet. Studies initially suggested an increase in energy expenditure, and thus energy requirements, as a direct result of an increase in basal metabolic rate often seen in disease. However, many problems exist in the measurement of BMR in a disease situation, due to the effects of drugs, clinical practice, feeding or possibly anxiety either as a cause of the disease or the measurement itself. These problems could in themselves contribute to the rise in metabolism seen in disease. More recently, however, with the use of tracer techniques such as doubly-labelled water and the bicarbonate–urea method, more accurate estimates of energy expenditure, and thus energy requirements, have been made. Some such measurements have in fact shown that even with an elevated BMR, free-living total energy expenditure can in fact be reduced in many disease situations, suggesting a reduced rather than an increased energy requirement. The present review investigates measurements of total energy expenditure in disease to explore the hypothesis that energy expenditure in disease, even with an elevated BMR, can in fact be reduced due to a concurrent reduction in physical activity.

Energy expenditure in children predicted from heart rate and activity calibrated against respiration calorimetry

1998 ◽  
Vol 275 (1) ◽  
pp. E12-E18 ◽  
Author(s):  
Margarita S. Treuth ◽  
Anne L. Adolph ◽  
Nancy F. Butte
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Carbon Dioxide Production ◽  
Vibration Sensor ◽  
Calibration Data ◽  
Regression Equations ◽  
Free Living ◽  
Acceptable Method ◽  
Activity Method ◽  
Separate Regression

The purpose of this study was to predict energy expenditure (EE) from heart rate (HR) and activity calibrated against 24-h respiration calorimetry in 20 children. HR, oxygen consumption (V˙o 2), carbon dioxide production (V˙co 2), and EE were measured during rest, sleep, exercise, and over 24 h by room respiration calorimetry on two separate occasions. Activity was monitored by a leg vibration sensor. The calibration day ( day 1) consisted of specified behaviors categorized as inactive (lying, sitting, standing) or active (two bicycle sessions). On the validation day ( day 2), the child selected activities. Separate regression equations forV˙o 2,V˙co 2, and EE for method 1 (combining awake and asleep using HR, HR2, and HR3), method 2 (separating awake and asleep), and method 3 (separating awake into active and inactive, and combining activity and HR) were developed using the calibration data. For day 1, the errors were similar for 24-hV˙o 2,V˙co 2, and EE among methods and also among HR, HR2, and HR3. The methods were validated using measured data from day 2. There were no significant differences in HR,V˙o 2,V˙co 2, respiratory quotient, and EE values during rest, sleep, or over the 24 h between days 1 and 2. Applying the linear HR equations to day 2 data, the errors were the lowest with the combined HR/activity method (−2.6 ± 5.2%, −4.1 ± 5.9%, −2.9 ± 5.1% forV˙o 2,V˙co 2, and EE, respectively). To demonstrate the utility of the HR/activity method, HR and activity were monitored for 24 h at home ( day 3). Free-living EE was predicted as 7,410 ± 1,326 kJ/day. In conclusion, the combination of HR and activity is an acceptable method for determining EE not only for groups of children, but for individuals.

Daily Energy Expenditure and Water-Turnover Rate of Adult European Starlings (Sturnus vulgaris) during the Nesting Cycle

The Auk ◽  
1984 ◽  
Vol 101 (4) ◽  
pp. 707-716 ◽  
Author(s):  
Robert E. Ricklefs ◽  
Joseph B. Williams
Keyword(s):  
Energy Expenditure ◽  
Weather Conditions ◽  
Carbon Dioxide Production ◽  
Co2 Production ◽  
Daily Energy Expenditure ◽  
Turnover Rates ◽  
Water Turnover ◽  
European Starlings ◽  
Nestling Period ◽  
Daily Energy

AbstractWe measured rates of carbon-dioxide production and water turnover in adult starlings by the doubly-labeled water technique. CO2 production of females was 4.23 cm3·g−1·h−1 during the incubation period, 4.86 cm3·g−1·h−1 during the early part of the nestling period, and 6.86 cm3·g−1·h−1 during the middle of the nestling period, the time of greatest food requirement by the brood. During the last period, the rate of CO2 production by males was 5.50 cm3·g−1·h−1. CO2 production was independent of brood size (3-7, approximately a two-fold range of brood mass) during both the early and middle parts of the nestling period. Water-turnover rates paralleled CO2 production over the nesting cycle, the average values for each sample varying between 0.048 and 0.070 per h. Within each of the samples, water-turnover rates were independent of CO2 production but appeared to be influenced by weather conditions. During the middle of the nestling period, water-turnover rates were higher on 2 cold, rainy days than on 2 milder days. The maximum daily energy expenditure for females was about four times predicted BMR, similar to values reported in other studies.

Physiological responses and energy expenditure during competitive fencing

2014 ◽  
Vol 39 (3) ◽  
pp. 324-328 ◽  
Author(s):  
Raffaele Milia ◽  
Silvana Roberto ◽  
Marco Pinna ◽  
Girolamo Palazzolo ◽  
Irene Sanna ◽  
...  
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Oxygen Uptake ◽  
Blood Lactate ◽  
Carbon Dioxide Production ◽  
Maximum Value ◽  
Average Group ◽  
Aerobic Energy Metabolism ◽  
Olympic Sport ◽  
Energetic Expenditure

Fencing is an Olympic sport in which athletes fight one against one using bladed weapons. Contests consist of three 3-min bouts, with rest intervals of 1 min between them. No studies investigating oxygen uptake and energetic demand during fencing competitions exist, thus energetic expenditure and demand in this sport remain speculative. The aim of this study was to understand the physiological capacities underlying fencing performance. Aerobic energy expenditure and the recruitment of lactic anaerobic metabolism were determined in 15 athletes (2 females and 13 males) during a simulation of fencing by using a portable gas analyzer (MedGraphics VO2000), which was able to provide data on oxygen uptake, carbon dioxide production and heart rate. Blood lactate was assessed by means of a portable lactate analyzer. Average group energetic expenditure during the simulation was (mean ± SD) 10.24 ± 0.65 kcal·min−1, corresponding to 8.6 ± 0.54 METs. Oxygen uptakeand heart rate were always below the level of anaerobic threshold previously assessed during the preliminary incremental test, while blood lactate reached its maximum value of 6.9 ± 2.1 mmol·L−1 during the final recovery minute between rounds. Present data suggest that physical demand in fencing is moderate for skilled fencers and that both aerobic energy metabolism and anaerobic lactic energy sources are moderately recruited. This should be considered by coaches when preparing training programs for athletes.

Validation of the BIOPAC indirect calorimeter for determining resting energy expenditure in healthy free-living older people

2009 ◽  
Vol 29 (8) ◽  
pp. 531-541 ◽  
Author(s):  
Kerstin Khalaj-Hedayati ◽  
Anja Bosy-Westphal ◽  
Manfred J. Müller ◽  
Manuela Dittmar
Keyword(s):  
Energy Expenditure ◽  
Older People ◽  
Resting Energy Expenditure ◽  
Free Living ◽  
Resting Energy

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

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