Measurement of bicarbonate turnover in humans: applicability to estimation of energy expenditure

1992 ◽  
Vol 263 (4) ◽  
pp. E676-E687 ◽  
Author(s):  
M. Elia ◽  
N. J. Fuller ◽  
P. R. Murgatroyd
Keyword(s):  
Energy Expenditure ◽  
Total Energy ◽  
Specific Activity ◽  
Bladder Wall ◽  
Total Energy Expenditure ◽  
Whole Body ◽  
Co2 Production ◽  
Constant Infusion ◽  
Healthy Male ◽  
Short Term

Bicarbonate turnover and energy expenditure were assessed in six healthy male volunteers, by the use of a constant infusion of radiolabeled bicarbonate (NaH14CO3) administered over 36 h, while the volunteers were confined to a whole body indirect calorimeter. Recovery and dilution of isotope were assessed from measurements made on continuous collections of CO2, entering and leaving the calorimeter, urine, and intermittent spot breath and saliva samples. Mean recovery of infused label in gaseous CO2 was 95.6 +/- 1.1% (SD) between 12 and 36 h. Applying a 95% mean recovery of label to each subject individually enabled the use of integrated mean specific activity of CO2 in spot breath and urine samples to predict measured net CO2 production and energy expenditure to within about +/- 6%. Estimates based on urinary measurements were compromised slightly by the exchange of label through the bladder wall (this was dependent on pH and volume of urine). It is concluded that this constant-infusion labeled bicarbonate method offers a potentially useful means of assessing net CO2 production and total energy expenditure over the short term (e.g., 1-3 days).

Estimating energy expenditure from specific activity of urine urea during lengthy subcutaneous NaH14CO3 infusion

1995 ◽  
Vol 269 (1) ◽  
pp. E172-E182 ◽  
Author(s):  
M. Elia ◽  
M. G. Jones ◽  
G. Jennings ◽  
S. D. Poppitt ◽  
N. J. Fuller ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Healthy Subjects ◽  
Specific Activity ◽  
Daily Variation ◽  
Whole Body ◽  
Co2 Production ◽  
Healthy Male ◽  
Male Subjects ◽  
Urea Method ◽  
Mini Pump

Five healthy male subjects were continuously infused subcutaneously with [14C]bicarbonate (12.3 microCi/day) using a mini pump for 5 days while in a whole body calorimeter. Energy expenditure was varied over a range of 1.35-1.75 times basal metabolic rate. Urine collections were obtained throughout the study and used to measure the specific activity of urea, from which CO2 production was estimated. It was assumed that the recovery of label in gaseous CO2 was 95% of that infused and that the specific activity of urea was 85% that of expired CO2. Continuous daily collections of calorimeter air revealed that 95.6 +/- 1.3% (SD) of infused label was recovered as gaseous CO2, with little daily variation. Another 1.5 +/- 0.4% was recovered as urinary urea. The estimated CO2 production, calculated from the specific activity of urea in 24-h urine samples corrected for the small effects due to changes in the size and specific activity of the urea pool, was found to be 100 +/- 5% of the calorimeter estimate for 1-day periods (20.80 +/- 1.44 mol CO2/day) and 100 +/- 2% for 4-day periods. This study suggests that, in healthy subjects, the labeled [14C]bicarbonate-urea method can provide reasonable estimates of net CO2 production over the range examined.

scholarly journals Total energy expenditure assessed by salivary doubly labelled water analysis and its relevance for short-term energy balance in humans

2015 ◽  
Vol 30 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Stefano Guidotti ◽  
Berthe M. A. A. A. Verstappen-Dumoulin ◽  
Henk G. Jansen ◽  
Anita T. Aerts-Bijma ◽  
André A. van Vliet ◽  
...  
Keyword(s):  
Energy Balance ◽  
Energy Expenditure ◽  
Total Energy ◽  
Water Analysis ◽  
Total Energy Expenditure ◽  
Short Term ◽  
Doubly Labelled Water ◽  
Term Energy

Effect of elevated FFA on carbohydrate and lipid oxidation during prolonged exercise in humans

1986 ◽  
Vol 60 (3) ◽  
pp. 893-900 ◽  
Author(s):  
E. Ravussin ◽  
C. Bogardus ◽  
K. Scheidegger ◽  
B. LaGrange ◽  
E. D. Horton ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Energy Expenditure ◽  
Total Energy ◽  
Prolonged Exercise ◽  
Total Energy Expenditure ◽  
Constant Infusion ◽  
Base Line ◽  
O2 Uptake ◽  
Glucose Ingestion ◽  
Exercise In Humans

Increased availability of circulating free fatty acids (FFA) inhibits the rate of glycolysis in heart and resting skeletal muscle (Randle effect). Whether elevated FFA may play a role in decreasing carbohydrate oxidation during prolonged exercise in humans is more controversial. Using respiratory exchange measurements, we measured substrate utilization during 2.5 h of exercise at approximately 44 +/- 1% maximal O2 uptake (VO2 max) in the presence or absence of elevated FFA levels. After 30 min of base-line determinations, 1,000 U heparin was given intravenously and a 3-h constant infusion of Intralipid 10% (150 g/h) and heparin (500 U/h) was started. After an additional 30 min of rest, subjects exercised for 2.5 h (study 1, n = 6). In another five subjects (study 2) 100 g glucose was ingested after 30 min of exercise. The same protocols (studies 1 and 2) were also performed during a 0.9%-saline infusion. During exercise, without glucose ingestion, higher FFA concentrations prevailed during the Intralipid infusion (1,122 +/- 40 vs. 782 +/- 65 mumol/l), but the relative contributions of carbohydrate (49 +/- 4 vs. 50 +/- 4%) or lipid (49 +/- 4 vs. 47 +/- 6%) oxidation to the total energy expenditure were different only during the first 30 min of exercise. Similarly, higher FFA levels (1,032 +/- 62 vs. 568 +/- 46 mumol/l) did not alter the relative contributions of carbohydrate (62 +/- 4 vs. 69 +/- 2%) or lipid (36 +/- 4 vs. 29 +/- 2%) oxidation to the total energy expenditure after glucose feeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Total energy expenditure in burned children using the doubly labeled water technique

1990 ◽  
Vol 259 (4) ◽  
pp. E576-E585 ◽  
Author(s):  
M. I. Goran ◽  
E. J. Peters ◽  
D. N. Herndon ◽  
R. R. Wolfe
Keyword(s):  
Energy Expenditure ◽  
Total Energy ◽  
Resting Energy Expenditure ◽  
Total Energy Expenditure ◽  
High Rate ◽  
Co2 Production ◽  
Doubly Labeled Water ◽  
Water Turnover ◽  
Activity Factor ◽  
Basal Energy Expenditure

Total energy expenditure (TEE) was measured in 15 burned children with the doubly labeled water technique. Application of the technique in burned children required evaluation of potential errors resulting from nutritional intake altering background enrichments during studies and from the high rate of water turnover relative to CO2 production. Five studies were discarded because of these potential problems. TEE was 1.33 +/- 0.27 times predicted basal energy expenditure (BEE), and in studies where resting energy expenditure (REE) was simultaneously measured, TEE was 1.18 +/- 0.17 times REE, which in turn was 1.16 +/- 0.10 times predicted BEE. TEE was significantly correlated with measured REE (r2 = 0.92) but not with predicted BEE. These studies substantiate the advantage of measuring REE to predict TEE in severely burned patients as opposed to relying on standardized equations. Therefore we recommend that optimal nutritional support will be achieved in convalescent burned children by multiplying REE by an activity factor of 1.2.

Oxidative metabolism in insulin-treated gestational diabetes mellitus

1997 ◽  
Vol 272 (6) ◽  
pp. E1099-E1107
Author(s):  
H. W. Hsu ◽  
N. F. Butte ◽  
W. W. Wong ◽  
J. K. Moon ◽  
K. J. Ellis ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Energy Expenditure ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Total Energy ◽  
Carbon Dioxide Production ◽  
Total Energy Expenditure ◽  
Fat Free Mass ◽  
Whole Body ◽  
Breath Co2

To investigate whether protein, carbohydrate, and fat metabolism was normalized in insulin-treated gestational diabetes mellitus (GDM), eight Hispanic women with GDM and eight healthy controls were studied at 32-36 wk of gestation and 6 wk postpartum. Net substrate utilization was measured using room respiration calorimetry. Exogenous substrate oxidation was determined by 13C recovered in breath CO2 from 13C-labeled leucine, glucose, and Hiolein. Women with GDM had higher 24-h oxygen consumption, carbon dioxide production, total energy expenditure, and basal metabolic rates than controls due to larger body mass. Adjusted for weight or fat-free mass, total energy expenditure, basal metabolic rate, and basal and 24-h whole body net protein, carbohydrate, and fat utilization did not differ between insulin-treated GDM subjects and controls in pregnancy or postpartum. Oxidation of [13C]leucine and [13C]glucose did not differ by group or pregnancy status. Recovery of exogenously administered [13C]Hiolein, a biosynthetic triglyceride, as breath 13CO2 was significantly lower in the GDM group antepartum and postpartum (P = 0.02), indicating lower oxidation of exogenous triglycerides in GDM.

Protein and energy metabolism in chronic bacterial infection: studies in melioidosis

2000 ◽  
Vol 100 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Nicholas I. PATON ◽  
Brian ANGUS ◽  
Wipada CHAOWAGUL ◽  
Andrew J. SIMPSON ◽  
Yupin SUPUTTAMONGKOL ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Energy Expenditure ◽  
Bacterial Infection ◽  
Total Energy ◽  
Protein Turnover ◽  
Resting Energy Expenditure ◽  
Total Energy Expenditure ◽  
Whole Body ◽  
Anabolic Response ◽  
Resting Energy

Chronic infection is often accompanied by a wasting process, the metabolic basis of which is not fully understood. The aims of the present study were to measure protein and energy metabolism in patients with melioidosis (a serious and antibiotic-refractory Gram-negative bacterial infection which is endemic in South-East Asia) in order to define the metabolic abnormalities that might contribute to wasting. Whole-body protein turnover was measured using the [13C]leucine technique, both in the fasted state and while consuming a high-energy meal. Resting energy expenditure was measured by indirect calorimetry, and total energy expenditure by the bicarbonate/urea method. Results were normalized for fat-free mass, as estimated from skinfold thickness. Protein turnover was increased in melioidosis patients compared with healthy controls during fasting (170.9 compared with 124.1 µmol·kg-1·h-1; P = 0.04), but the net rate of catabolism (22.2 compared with 20.5 µmol·kg-1·h-1; P = 0.77) and the anabolic response to feeding were similar in the two groups. Resting energy expenditure was higher in melioidosis patients compared with controls (191.4 and 157.3 kJ·kg-1·day-1 respectively; P = 0.04), but total energy expenditure (measured in a separate group of eight patients with melioidosis) was low (192.1 kJ·kg-1·day-1). In conclusion, this study found no evidence of metabolic causative factors, such as accelerated net protein catabolism during fasting, a blunted anabolic response to feeding or increased daily energy expenditure, and therefore suggests that reduced energy intake is the prime cause of wasting. The observed normal response to feeding should encourage nutritional approaches to prevent wasting.

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