scholarly journals Female rats selectively bred for high intrinsic aerobic fitness are protected from ovariectomy-associated metabolic dysfunction

2015 ◽  
Vol 308 (6) ◽  
pp. R530-R542 ◽  
Author(s):  
Victoria J. Vieira-Potter ◽  
Jaume Padilla ◽  
Young-Min Park ◽  
Rebecca J. Welly ◽  
Rebecca J. Scroggins ◽  
...  
Keyword(s):  
Physical Activity ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Energy Expenditure ◽  
Aerobic Fitness ◽  
Resting Energy Expenditure ◽  
Female Rats ◽  
Metabolic Dysfunction ◽  
Spontaneous Physical Activity ◽  
Resting Energy

Ovariectomized rodents model human menopause in that they rapidly gain weight, reduce spontaneous physical activity (SPA), and develop metabolic dysfunction, including insulin resistance. How contrasting aerobic fitness levels impacts ovariectomy (OVX)-associated metabolic dysfunction is not known. Female rats selectively bred for high and low intrinsic aerobic fitness [high-capacity runners (HCR) and low-capacity runners (LCR), respectively] were maintained under sedentary conditions for 39 wk. Midway through the observation period, OVX or sham (SHM) operations were performed providing HCR-SHM, HCR-OVX, LCR-SHM, and LCR-OVX groups. Glucose tolerance, energy expenditure, and SPA were measured before and 4 wk after surgery, while body composition via dual-energy X-ray absorptiometry and adipose tissue distribution, brown adipose tissue (BAT), and skeletal muscle phenotype, hepatic lipid content, insulin resistance via homeostatic assessment model of insulin resistance and AdipoIR, and blood lipids were assessed at death. Remarkably, HCR were protected from OVX-associated increases in adiposity and insulin resistance, observed only in LCR. HCR rats were ∼30% smaller, had ∼70% greater spontaneous physical activity (SPA), consumed ∼10% more relative energy, had greater skeletal muscle proliferator-activated receptor coactivator 1-alpha, and ∼40% more BAT. OVX did not increase energy intake and reduced SPA to the same extent in both HCR and LCR. LCR were particularly affected by an OVX-associated reduction in resting energy expenditure and experienced a reduction in relative BAT; resting energy expenditure correlated positively with BAT across all animals ( r = 0.6; P < 0.001). In conclusion, despite reduced SPA following OVX, high intrinsic aerobic fitness protects against OVX-associated increases in adiposity and insulin resistance. The mechanism may involve preservation of resting energy expenditure.

scholarly journals Mitochondrial Function and Insulin Resistance in Overweight and Normal-Weight Children

2009 ◽  
Vol 94 (12) ◽  
pp. 4923-4930 ◽  
Author(s):  
Amy Fleischman ◽  
Matthew Kron ◽  
David M. Systrom ◽  
Mirko Hrovat ◽  
Steven K. Grinspoon
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Energy Expenditure ◽  
Mitochondrial Function ◽  
Resting Energy Expenditure ◽  
Normal Weight ◽  
Metabolic Phenotype ◽  
Overweight Children ◽  
Insulin Resistant ◽  
Resting Energy

Background: Obesity has become an epidemic in children, associated with an increase in insulin resistance and metabolic dysfunction. Mitochondrial function is known to be an important determinant of glucose metabolism in adults. However, little is known about the relationship between mitochondrial function and obesity, insulin resistance, energy expenditure, and pubertal development in children. Methods: Seventy-four participants, 37 overweight (≥85th percentile body mass index for age and sex) and 37 normal-weight (&lt;85th percentile) without personal or family history of diabetes mellitus were enrolled. Subjects were evaluated with an oral glucose tolerance test, metabolic markers, resting energy expenditure, Tanner staging, and 31P magnetic resonance spectroscopy of skeletal muscle for mitochondrial function. Results: Overweight and normal-weight children showed no difference in muscle ATP synthesis [phosphocreatine (PCr) recovery after exercise] (32.4 ± 2.3 vs. 34.1 ± 2.1, P = 0.58). However, insulin-resistant children had significantly prolonged PCr recovery when compared with insulin-sensitive children, by homeostasis model assessment for insulin resistance quartile (ANOVA, P = 0.04). Similarly, insulin-resistant overweight children had PCr recovery that was prolonged compared with insulin-sensitive overweight children (P = 0.01). PCr recovery was negatively correlated with resting energy expenditure in multivariate modeling (P = 0.03). Mitochondrial function worsened during mid-puberty in association with insulin resistance. Conclusion: Reduced skeletal muscle mitochondrial oxidative phosphorylation, assessed by PCr recovery, is associated with insulin resistance and an altered metabolic phenotype in children. Normal mitochondrial function may be associated with a healthier metabolic phenotype in overweight children. Further studies are needed to investigate the long-term physiological consequences and potential treatment strategies targeting children with reduced mitochondrial function.

Possible mechanisms of metabolic dysfunction in ovariectomized rats : impact of intrinsic aerobic fitness

2015 ◽  
Author(s):  
◽  
Young-Min Park
Keyword(s):  
Physical Activity ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Aerobic Capacity ◽  
Aerobic Fitness ◽  
Wheel Running ◽  
Critical Role ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Metabolic Dysfunction

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Ovariectomized (OVX) rodents are used as a model of human menopause as frequently both experience weight gain, decreased insulin sensitivity and decreased physical activity, which may manifest into metabolic syndrome. Intrinsic aerobic capacity may influence OVX-induced metabolic dysfunction. Female rats selectively bred for high (HCR) and low (LCR) aerobic capacity were used to elucidate the underlying mechanisms by which intrinsic aerobic fitness impacts OVX-associated metabolic dysfunction. We demonstrated that HCR were not fully protected against an OVX-induced decline in insulin sensitivity partially due to a [about]30% attenuation of insulin-stimulated skeletal muscle glucose uptake. HCROVX were protective against HFD-associated insulin resistance through a unique mechanism of behavioral change (i.e. compensatory increase in spontaneous physical activity), while LCROVX exacerbated insulin resistance following HFD. HCR were not protected from OVX-induced reduction in voluntary wheel running; yet HCRhad greater DA activation, compared to LCR, which was associated with their enhanced running distance. Collectively, these data suggest that high aerobic fitness may play a critical role in attenuating metabolic dysfunction associated with OVX and external stress due to their intrinsically enhanced insulin sensitivity. However, high aerobic fitness is not fully protective to OVX-induced impairments in metabolic function and physical activity levels, indicative of a strong physiological effect of ovarian hormone loss.

Total Energy Expenditure and Physical Activity Measured with the Bicarbonate-Urea Method in Patients with Human Immunodeficiency Virus Infection

1996 ◽  
Vol 91 (2) ◽  
pp. 241-245 ◽  
Author(s):  
N. I. J. Paton ◽  
M. Elia ◽  
S. A. Jebb ◽  
G. Jennings ◽  
D. C. MacAllan ◽  
...  
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Total Energy ◽  
Physical Activity Level ◽  
Resting Energy Expenditure ◽  
Total Energy Expenditure ◽  
Activity Level ◽  
Hiv Positive ◽  
Urea Method ◽  
Resting Energy

1. Our objectives were to measure total energy expenditure, the daily variation in total energy expenditure and the physical activity level in a group of HIV-positive subjects using the bicarbonate-urea method. The study also aimed to assess the practicalities of using the bicarbonate-urea technique in free-living conditions. 2. Total energy expenditure was measured with the bicarbonate-urea method over 2 consecutive days (1 day in one subject) in 10 male patients with HIV infection (median CD4 count = 30). Resting energy expenditure was measured by indirect calorimetry. Physical activity level (total energy expenditure/resting energy expenditure) was calculated from these measurements and from activity diaries. 3. Resting energy expenditure was found to be 7.46 ± 0.87 MJ/day, 5% higher than predicted values. Total energy expenditure was 10.69 ± 1.95 MJ/day with an intra-individual day-to-day variation of 6 ± 6%. The measured physical activity level was 1.42 ± 0.14, higher than the diary estimate of 1.34 ± 0.16 (P = 0.029), and there were large inter-method differences in individual values. The subcutaneous infusion of bicarbonate was well tolerated and did not seem to restrict normal activities. 4. Total energy expenditure was not elevated in the group of HIV-positive subjects when compared with reference values for normal subjects. The physical activity level of the patients in this study was lower than that measured using other techniques in healthy young men, but was compatible with that expected for people leading a sedentary lifestyle. Reductions in physical activity in patients with HIV are likely to contribute to the wasting process and physical activity level may thus be a clinically useful measure. This study has also provided the first tracer estimate of the day-to-day variation in total energy expenditure. The bicarbonate-urea method represents an important new investigative tool for measuring total energy expenditure which has previously only been possible within the confines of a whole-body calorimeter or using the expensive doubly labelled water method.

scholarly journals Association of FTO and ADRB2 gene variation with energy restriction induced adaptations in resting energy expenditure and physical activity

Gene X ◽  
2019 ◽  
Vol 3 ◽  
pp. 100019
Author(s):  
Stefan G.J.A. Camps ◽  
Sanne P.M. Verhoef ◽  
Freek G. Bouwman ◽  
Edwin C.M. Mariman ◽  
Klaas R. Westerterp
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Resting Energy Expenditure ◽  
Energy Restriction ◽  
Gene Variation ◽  
Adrb2 Gene ◽  
Resting Energy

scholarly journals Physical activity and energy balance

1999 ◽  
Vol 2 (3a) ◽  
pp. 335-339 ◽  
Author(s):  
Marleen A. Van Baak
Keyword(s):  
Physical Activity ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Total Energy ◽  
Energy Intake ◽  
Body Mass ◽  
Resting Energy Expenditure ◽  
Total Energy Expenditure ◽  
Activity Level ◽  
Resting Energy

AbstractEnergy expenditure rises above resting energy expenditure when physical activity is performed. The activity-induced energy expenditure varies with the muscle mass involved and the intensity at which the activity is performed: it ranges between 2 and 18 METs approximately. Differences in duration, frequency and intensity of physical activities may create considerable variations in total energy expenditure. The Physical Activity Level (= total energy expenditure divided by resting energy expenditure) varies between 1.2 and 2.2–2.5 in healthy adults. Increases in activity-induced energy expenditure have been shown to result in increases in total energy expenditure, which are usually greater than the increase in activity-induced energy expenditure itself. No evidence for increased spontaneous physical activity, measured by diary, interview or accelerometer, was found. However, this does not exclude increased physical activity that can not be measured by these methods. Part of the difference may also be explained by the post-exercise elevation of metabolic rate.If changes in the level of physical activity affect energy balance, this should result in changes in body mass or body composition. Modest decreases of body mass and fat mass are found in response to increases in physical activity, induced by exercise training, which are usually smaller than predicted from the increase in energy expenditure. This indicates that the training-induced increase in total energy expenditure is at least partly compensated for by an increase in energy intake. There is some evidence that the coupling between energy expenditure and energy intake is less at low levels of physical activity. Increasing the level of physical activity for weight loss may therefore be most effective in the most sedentary individuals.

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