Effects of glucose-to-lipid ratio and type of lipid on substrate oxidation rate in patients

1994 ◽  
Vol 267 (5) ◽  
pp. E775-E780 ◽  
Author(s):  
B. Delafosse ◽  
J. P. Viale ◽  
S. Tissot ◽  
S. Normand ◽  
C. Pachiaudi ◽  
...  
Keyword(s):  
Oxidation Rate ◽  
Minute Ventilation ◽  
Caloric Intake ◽  
Carbon Dioxide Production ◽  
Substrate Oxidation ◽  
Co2 Production ◽  
Oxidation Rates ◽  
Lipid Ratios ◽  
Mass Spectrometer System ◽  
Spectrometer System

This study is an investigation into the effects of different carbohydrate-to-lipid ratios on CO2 production in postoperative patients and the determination of the substrate oxidation rates induced by long-chain triglycerides (LCT) or a mixture of long- and medium-chain triglycerides (MCT/LCT) at various carbohydrate-to-lipid ratios. Two groups of eight patients randomly received either LCT or MCT/LCT emulsions. Total caloric intake was set at the measured energy expenditure provided at three different glucose-to-lipid ratios (70:30, 50:50, 30:70). We used long-term indirect calorimetry with a mass spectrometer system and measurement of natural enrichment in 13C of expired CO2 and plasma glucose. The carbon dioxide production and minute ventilation were not different among the different glucose-to-lipid ratios, whatever the type of lipid. Increasing the lipid supply up to 70% of nonprotein caloric intake led to an only minor increase in lipid oxidation rate and thus to a net fat deposit. We conclude that large amounts of lipid (LCT or MCT/LCT) were not of interest in such patients.

Substrate oxidation during exercise in taekwondo athletes: impact of aerobic fitness status

2020 ◽  
Vol 16 (5) ◽  
pp. 371-376
Author(s):  
B. Taati ◽  
H. Rohani
Keyword(s):  
Aerobic Fitness ◽  
Oxidation Rate ◽  
Fat Oxidation ◽  
Potential Effect ◽  
Substrate Oxidation ◽  
Training Experience ◽  
Male Athletes ◽  
Fitness Level ◽  
Oxidation Rates ◽  
Maximal Fat Oxidation

The present study aimed to investigate the potential effect of different aerobic fitness levels on substrate oxidation in trained taekwondo athletes. 57 male athletes (age 21.10±7.79 years; VO2max 50.67±6.67 ml/kg/min) with regular weekly taekwondo training and training experience of at least three years completed a graded exercise test to exhaustion on a treadmill. Maximal fat oxidation (MFO), the exercise intensity related to MFO (Fatmax), and carbohydrate (CHO) oxidation rate were measured using indirect calorimetry methods. The athletes then were divided into a low (<50 ml/kg/min, n=18) and high (>50 ml/kg/min, n=39) VO2max group. The average MFO was higher in the high VO2max group than in the low VO2max group (0.46±0.19 vs 0.28±0.11 g/min; P<0.001). Although Fatmax tended toward higher values in the high VO2max group, no difference was observed between the groups (49.15±15.22 vs 42.42±12.37% of VO2max; P=0.18). It was also shown that the high VO2max group had a lower CHO oxidation rate and a higher fat oxidation rate at given exercise intensities. In conclusion, it seems that MFO and substrate oxidation rates in taekwondo athletes can be influenced by aerobic fitness level such that the athletes with higher VO2max appeared to use more fat as a fuel source for energy supply during a given exercise.

Comparison of indirect calorimetry and a new breath 13C/12C ratio method during strenuous exercise

1992 ◽  
Vol 263 (1) ◽  
pp. E64-E71 ◽  
Author(s):  
J. A. Romijn ◽  
E. F. Coyle ◽  
J. Hibbert ◽  
R. R. Wolfe
Keyword(s):  
Indirect Calorimetry ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Co2 Production ◽  
Strenuous Exercise ◽  
Ratio Method ◽  
O2 Uptake ◽  
Underlying Assumption ◽  
Oxidation Rates

A new stable isotope method for the determination of substrate oxidation rates in vivo is described and compared with indirect calorimetry at rest and during high-intensity exercise (30 min at 80-85% maximal O2 uptake capacity) in six well-trained cyclists. This method uses the absolute ratios of 13C/12C in expired air, endogenous glucose, fat, and protein in addition to O2 consumption and is independent of CO2 production (VCO2). Carbohydrate and fat oxidation rates at rest, calculated by both methods, were not significantly different. During exercise the breath 13C/12C ratio increased and reached a steady state after 15-20 min. Carbohydrate oxidation rates during exercise were 39.4 +/- 5.2 and 41.7 +/- 5.7 mg.kg-1.min-1 [not significant (NS)], and fat oxidation rates were 7.3 +/- 1.3 and 6.9 +/- 1.2 mg.kg-1.min-1 (NS), using indirect calorimetry, and the breath ratio method, respectively. We conclude that the breath 13C/12C ratio method can be used to calculate substrate oxidation under different conditions, such as the basal state and exercise. In addition, the results obtained by this new method support the validity of the underlying assumption that indirect calorimetry regards VCO2 as a reflection of tissue CO2 production, during exercise in trained subjects, even up to 80-85% maximal O2 uptake.

scholarly journals Ghrelin, insulin sensitivity and postprandial glucose disposal in overweight and obese children

2006 ◽  
Vol 154 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Claudio Maffeis ◽  
Riccardo C Bonadonna ◽  
Alessandro Consolaro ◽  
Roberto Vettor ◽  
Claudia Banzato ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Test Meal ◽  
Oxidation Rate ◽  
Standard Deviation Score ◽  
Substrate Oxidation ◽  
Carbohydrate Oxidation ◽  
Glucose Disposal ◽  
Obese Children ◽  
Oxidation Rates ◽  
Different Levels

Objective: To explore the changes of ghrelin circulating levels induced by a mixed meal and their relationship with postprandial substrate oxidation rates in overweight and obese children with different levels of insulin sensitivity. Methods: A group of ten boys (age 9–12 years) with different levels of overweight (standard deviation score of body mass index: 1.6–3.2) was recruited. Body composition was measured by dual-energy X-ray absorptiometry. Insulin sensitivity was assessed by a frequently sampled i.v. glucose tolerance test. Pre-prandial and postprandial (3 h) substrate oxidation was measured by indirect calorimetry. The energy content of the test meal (16% protein, 36% carbohydrate and 48% fat) was 40% of pre-prandial energy expenditure (kJ/day). Results: Pre-prandial serum concentration of total ghrelin was 701.4±66.9 pg/ml (S.E.M.). The test meal induced a rapid decrease in ghrelin levels and maximal decrease was 27.3±2.7% below baseline. Meal intake induced a progressive increase of the carbohydrate oxidation rate for 45 min after food ingestion, followed by a slow decrease without returning to pre-prandial values. Postprandial cumulative carbohydrate oxidation was 16.9±0.8 g/3 h. Insulin sensitivity and postprandial maximal decrease of ghrelin concentration showed a significant correlation (r = 0.803, P < 0.01). Moreover, the postprandial carbohydrate oxidation rate correlated with the area under the curve for both insulin (r = 0.673, P < 0.03) and ghrelin (r = −0.661, P < 0.04). Conclusions: A relevant association between postprandial insulin-mediated glucose metabolism and ghrelin secretion in children with different levels of overweight was found. It is possible that the maintenance of an adequate level of insulin sensitivity and glucose oxidation may affect appetite regulation by favoring a more efficient postprandial ghrelin reduction.

The Interaction of Obesity and Puberty on Substrate Utilization During Exercise: A Gender Comparison

2011 ◽  
Vol 23 (3) ◽  
pp. 411-431 ◽  
Author(s):  
Robert G. McMurray ◽  
Peter A. Hosick
Keyword(s):  
Oxidation Rate ◽  
Substrate Oxidation ◽  
Substrate Utilization ◽  
Normal Weight ◽  
Carbohydrate Oxidation ◽  
Metabolic Rates ◽  
Substrate Use ◽  
Gender Comparison ◽  
Oxidation Rates ◽  
Prepubertal Boys

The study evaluated the interactions of puberty and obesity on substrate oxidation of overweight girls (n = 38) and boys (N = 35; BMI > 85th percentile) matched for gender, age, and puberty (pre/pubertal) with normal weight girls and boys. Metabolic rates (VO2) were obtained during rest and at 4, 5.6 and 8 k/h. Carbohydrate oxidation rates (mg/kgFFM/min) adjusted for % predicted VO2max, were higher for prepubertal OW children than pubertal children (p < .03). Fat oxidation rates were higher for NW prepubertal boys compared with other boys. Results indicate that OW children, regardless of gender or pubertal status, increase their carbohydrate oxidation rate to compensate for higher than normal metabolic rates. The effects of obesity on the substrate use is marginally related to puberty.

scholarly journals Resting Energy Expenditure and Substrate Oxidation in Malnourished Patients With Type 1 Glycogenosis

2019 ◽  
Vol 104 (11) ◽  
pp. 5566-5572
Author(s):  
Silvio Buscemi ◽  
Davide Noto ◽  
Carola Buscemi ◽  
Anna Maria Barile ◽  
Giuseppe Rosafio ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Energy Expenditure ◽  
Rare Diseases ◽  
Protein Oxidation ◽  
Oxidation Rate ◽  
Resting Energy Expenditure ◽  
Substrate Oxidation ◽  
Small Sample ◽  
Oxidation Rates ◽  
Resting Energy

Abstract Context Type 1a and 1b glycogenosis [glycogen storage disorder (GSD)1a, GSD1b] are rare diseases generally associated with malnutrition. Although abnormal substrate oxidation rates and elevated energy expenditures might contribute to malnutrition, this issue has not been investigated. Objective To investigate whether abnormal resting energy expenditure (REE) and substrate oxidation rate characterize patients with GSD1. Design Cross-sectional study Setting Outpatient referral center for rare diseases and laboratory of clinical nutrition at the University Hospital of Palermo Patients Five consecutive patients with GSD1 (4 type a, 1 type b; 3 men, 2 women; age range, 19 to 49 years) Main Outcome Measures The usual clinical procedures for patients with malnutrition, including REE and basal substrate oxidation rate (both indirect calorimetry), body composition (bioimpedance method), muscle strength (hand-grip test), and the usual laboratory tests, were performed. Results Malnutrition was clearly diagnosed in 2 patients (1 GSD1a and 1 GSD1b), with REE elevated in all five patients, and especially, in the two malnourished patients (+124% and +32.1% vs predictive values using Harris-Benedict equations). The two malnourished patients also exhibited lower basal protein oxidation rates (7.7% and 6.6%) than the nourished patients (range, 12.1% to 24.7%), with higher carbohydrate or lipid oxidation rates. Additionally, the two malnourished patients exhibited higher blood concentrations of lactic acid than the nourished patients. Conclusions According to data obtained from our small sample of patients with GSD1, elevated REEs seem to be a common characteristic that might contribute to malnutrition. Low basal protein oxidation rates and elevated blood lactic acid concentrations appear to be associated with malnutrition.

scholarly journals Placebo Effect of Caffeine on Substrate Oxidation during Exercise

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 782
Author(s):  
Jorge Gutiérrez-Hellín ◽  
Carlos Ruiz-Moreno ◽  
Millán Aguilar-Navarro ◽  
Alejandro Muñoz ◽  
David Varillas-Delgado ◽  
...  
Keyword(s):  
Placebo Effect ◽  
Oxidation Rate ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Caffeine Intake ◽  
Similar Degree ◽  
Double Blind ◽  
Oxidation Rates ◽  
Maximal Fat Oxidation ◽  
Trial Participants

By using deceptive experiments in which participants are informed that they received caffeine when, in fact, they received an inert substance (i.e., placebo), several investigations have demonstrated that exercise performance can be enhanced to a similar degree as a known caffeine dose. This ‘placebo effect’ phenomenon may be part of the mechanisms explaining caffeine’s ergogenicity in exercise. However, there is no study that has established whether the placebo effect of caffeine is also present for other benefits obtained with acute caffeine intake, such as enhanced fat oxidation during exercise. Therefore, the aim of this investigation was to investigate the placebo effect of caffeine on fat oxidation during exercise. Twelve young men participated in a deceptive double-blind cross-over experiment. Each participant completed three identical trials consisting of a step incremental exercise test from 30 to 80% of V.O2max. In the two first trials, participants ingested either 3 mg/kg of cellulose (placebo) or 3 mg/kg of caffeine (received caffeine) in a randomized order. In the third trial, participants were informed that they had received 3 mg/kg of caffeine, but a placebo was provided (informed caffeine). Fat oxidation rates were derived from stoichiometric equations. In received caffeine, participants increased their rate of fat oxidation over the values obtained with the placebo at 30%, 40%, 50%, and 60% of V.O2max (all p < 0.050). In informed caffeine, participants increased their rate of fat oxidation at 30%, 40%, 50% 60%, and 70% of V.O2max (all p < 0.050) over the placebo, while there were no differences between received versus informed caffeine. In comparison to placebo (0.32 ± 0.15 g/min), the rate of maximal fat oxidation was higher in received caffeine (0.44 ± 0.22 g/min, p = 0.045) and in informed caffeine (0.41 ± 0.20 g/min, p = 0.026) with no differences between received versus informed caffeine. However, the intensity at which maximal fat oxidation rate was obtained (i.e., Fatmax) was similar in placebo, received caffeine, and informed caffeine trials (42.5 ± 4.5, 44.2 ± 9.0, and 41.7 ± 10.5% of V.O2max, respectively, p = 0.539). In conclusion, the expectancy of having received caffeine produced similar effects on fat oxidation rate during exercise than actually receiving caffeine. Therefore, the placebo effect of caffeine is also present for the benefits of acute caffeine intake on substrate oxidation during exercise and it may be used to enhance fat oxidation during exercise in participants while reducing any risks to health that this substance may have.

scholarly journals The Acute Effect of a Single Exhaustive Sprint Exercise Session on Post-Exercise Fat Oxidation Rate

2018 ◽  
Vol 10 (1) ◽  
pp. 118-126
Author(s):  
Zübeyde Aslankeser ◽  
Şükrü Serdar Balcı
Keyword(s):  
Energy Expenditure ◽  
Oxidation Rate ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Exhaustive Exercise ◽  
Exercise Session ◽  
Post Exercise ◽  
Sprint Exercise ◽  
Oxidation Rates ◽  
Study Results

Abstract It is well known that substrate oxidation rates are increased by exercise. The present study had two main objectives: firstly, to examine the effect of a single exhaustive exercise session on post-exercise substrate oxidation and energy expenditure; and secondly, to determine the differences between athletes and non-athletes.Material and methods: Eighteen healthy male athletes (mean ± SD age; 19.38 ± 2.26 years, VO2max; 60.57 ± 3.90 ml · kg-1 · min-1, n = 8) and non-athletes (age; 20.30 ± 1.26 years, VO2max; 44.97 ± 5.43 ml · kg-1 ·min-1, n = 10) volunteered to participate in the study. After an overnight fast, subjects performed a single sprint exercise session on a cycle ergometer with individual loads (0.075 kg per body weight) until volitional exhaustion. Energy expenditure (EE) and the substrate oxidation rate were measured at rest and during the post-exercise recovery period using indirect calorimetry. Results: Exhaustive exercise significantly increased post-exercise fat oxidation, energy expenditure and contribution of fat to EE (p < 0.05). Also, it significantly decreased post-exercise carbohydrate (CHO) oxidation and the contribution of CHO to EE (p < 0.05). However, the changes in the substrate oxidation rate and EE after the exercise test were not different between the groups (p > 0.05). Conclusions: The study results suggest that a single short-duration exhaustive exercise session causes a higher fat oxidation rate during recovery than at rest, whereas training status did not affect this situation

The Influence of Doping on the Etching of Si(111)

1986 ◽  
Vol 75 ◽  
Author(s):  
Harold F. Winters ◽  
D. Haarer
Keyword(s):  
Mass Spectrometer ◽  
Doping Level ◽  
Etch Rate ◽  
Plasma Reactors ◽  
Doping Effects ◽  
Mass Spectrometer System ◽  
Spectrometer System

AbstractIt has been recognized for some time that the doping level in silicon influences etch rate in plasma environments[1–8]. We have now been able to reproduce and investigate these doping effects in a modulated-beam, mass spectrometer system described previously [9] using XeF2 as the etchant gas. The phenomena which have been observed in plasma reactors containing fluorine atoms are also observed in our experiments. The data has led to a model which explains the major trends.

Ventilatory and hyperkalemic responses to incremental exercise after propranolol treatment

1994 ◽  
Vol 77 (4) ◽  
pp. 1907-1912 ◽  
Author(s):  
D. A. Schneider ◽  
M. T. McEniery ◽  
C. Solomon ◽  
J. Jurimae ◽  
M. S. Wehr
Keyword(s):  
Minute Ventilation ◽  
Plasma Potassium ◽  
Muscle Afferents ◽  
Incremental Exercise ◽  
Co2 Production ◽  
Beta Blockade ◽  
Adrenergic Blockade ◽  
Propranolol Treatment ◽  
Positive Correlations ◽  
And Control

The purpose of the present study was to examine the relationship of plasma potassium (K+) and minute ventilation (VE) during incremental cycling (20 W/2 min) under conditions of beta-adrenergic blockade (80 mg of propranolol) and placebo in six untrained male subjects. No significant differences existed between treatments in O2 uptake, CO2 production, blood lactate, pH, or VE during the submaximal work stages of incremental exercise common to both treatments (20–220 W). During exercise with beta-blockade, plasma K+ concentrations were found to be significantly elevated compared with control levels at every work stage except 20 W. Significant positive correlations between VE and plasma K+ were found during both beta-blockade (r = 0.99) and control conditions (r = 1.00). Although the high correlation between VE and K+ was not altered with beta-blockade, propranolol treatment resulted in a significant reduction in the slope of this relationship during incremental exercise (P < 0.01). These findings suggest that 1) beta-blockade decreases the VE-K+ relationship observed during exercise and 2) K+ stimulation of muscle afferents is not an important signal in the control of exercise ventilation.

Sexual influence on the control of breathing

1983 ◽  
Vol 54 (4) ◽  
pp. 874-879 ◽  
Author(s):  
D. P. White ◽  
N. J. Douglas ◽  
C. K. Pickett ◽  
J. V. Weil ◽  
C. W. Zwillich
Keyword(s):  
Ventilatory Response ◽  
Minute Ventilation ◽  
Premenopausal Women ◽  
Co2 Production ◽  
Menstrual Phase ◽  
Co2 Partial Pressure ◽  
Ventilatory Responses ◽  
Chemical Stimuli ◽  
Low Levels ◽  
Normal Women

Previous investigation has demonstrated that progesterone, a hormone found in premenopausal women, is a ventilatory stimulant. However, fragmentary data suggest that normal women may have lower ventilatory responses to chemical stimuli than men, in whom progesterone is found at low levels. As male-female differences have not been carefully studied, we undertook a systematic comparison of resting ventilation and ventilatory responses to chemical stimuli in men and women. Resting ventilation was found to correlate closely with CO2 production in all subjects (r = 0.71, P less than 0.001), but women tended to have a greater minute ventilation per milliliter of CO2 produced (P less than 0.05) and consequently a lower CO2 partial pressure (PCO2) (men 35.1 +/- 0.5 Torr, women 33.2 +/- 0.5 Torr; P less than 0.02). Women were also found to have lower tidal volumes, even when corrected from body surface area (BSA), and greater respiratory frequency than comparable males. The hypoxic ventilatory response (HVR) quantitated by the shape parameter A was significantly greater in men [167 +/- 22 (SE)] than in women (109 +/- 13; P less than 0.05). In men this hypoxic response was found to correlate closely with O2 consumption (r = 0.75, P less than 0.001) but with no measure of size or metabolic rate in women. The hypercapnic ventilatory response, expressed as the slope of ventilation vs. PCO2, was also greater in men (2.30 +/- 0.23) than in women (1.58 +/- 0.19, P less than 0.05). Finally women tended to have higher ventilatory responses in the luteal than in the follicular menstrual phase, but this was significant only for HVR (P less than 0.05). Women, with relatively higher resting ventilation, have lower responses to hypoxia and hypercapnia.

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