scholarly journals Blood flow to long bones indicates activity metabolism in mammals, reptiles and dinosaurs

2011 ◽  
Vol 279 (1728) ◽  
pp. 451-456 ◽  
Author(s):  
Roger S. Seymour ◽  
Sarah L. Smith ◽  
Craig R. White ◽  
Donald M. Henderson ◽  
Daniela Schwarz-Wings
Keyword(s):  
Blood Flow ◽  
Body Size ◽  
Metabolic Rate ◽  
Bone Cells ◽  
Bone Remodelling ◽  
Resting Metabolic Rate ◽  
Blood Flow Rate ◽  
Whole Body ◽  
Long Bone ◽  
Cross Sectional

The cross-sectional area of a nutrient foramen of a long bone is related to blood flow requirements of the internal bone cells that are essential for dynamic bone remodelling. Foramen area increases with body size in parallel among living mammals and non-varanid reptiles, but is significantly larger in mammals. An index of blood flow rate through the foramina is about 10 times higher in mammals than in reptiles, and even higher if differences in blood pressure are considered. The scaling of foramen size correlates well with maximum whole-body metabolic rate during exercise in mammals and reptiles, but less well with resting metabolic rate. This relates to the role of blood flow associated with bone remodelling during and following activity. Mammals and varanid lizards have much higher aerobic metabolic rates and exercise-induced bone remodelling than non-varanid reptiles. Foramen areas of 10 species of dinosaur from five taxonomic groups are generally larger than from mammals, indicating a routinely highly active and aerobic lifestyle. The simple measurement holds possibilities offers the possibility of assessing other groups of extinct and living vertebrates in relation to body size, behaviour and habitat.

scholarly journals Cardiovascular Physiology of Dinosaurs

Physiology ◽  
2016 ◽  
Vol 31 (6) ◽  
pp. 430-441 ◽  
Author(s):  
Roger S. Seymour
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Body Size ◽  
Metabolic Rate ◽  
Flow Rate ◽  
Direct Evidence ◽  
Blood Flow Rate ◽  
Cardiovascular Physiology ◽  
Arterial Blood ◽  
Heart Size

Cardiovascular function in dinosaurs can be inferred from fossil evidence with knowledge of how metabolic rate, blood flow rate, blood pressure, and heart size are related to body size in living animals. Skeletal stature and nutrient foramen size in fossil femora provide direct evidence of a high arterial blood pressure, a large four-chambered heart, a high aerobic metabolic rate, and intense locomotion. But was the heart of a huge, long-necked sauropod dinosaur able to pump blood up 9 m to its head?

Nutrient pattern of unsaturated fatty acids and vitamin E increase resting metabolic rate of overweight and obese women

2020 ◽  
pp. 1-9
Author(s):  
Habib Yarizadeh ◽  
Leila Setayesh ◽  
Caroline Roberts ◽  
Mir Saeed Yekaninejad ◽  
Khadijeh Mirzaei
Keyword(s):  
Vitamin E ◽  
Metabolic Rate ◽  
Unsaturated Fatty Acids ◽  
Resting Metabolic Rate ◽  
Blood Parameters ◽  
Cross Sectional Study ◽  
Obese Women ◽  
Cross Sectional ◽  
Dietary Nutrients ◽  
Nutrient Patterns

Abstract. Objectives: Obesity plays an important role in the development of chronic diseases including cardiovascular disease and diabetes. A low resting metabolic rate (RMR) for a given body size and composition is a risk factor for obesity, however, there is limited evidence available regarding the association of nutrient patterns and RMR. The aim of this study was to determine the association of nutrient patterns and RMR in overweight and obese women. Study design: This cross-sectional study was conducted on 360 women who were overweight or obese. Method: Dietary intake was assessed using a semi-quantitative standard food frequency questionnaire (FFQ). Nutrient patterns were also extracted by principal components analysis (PCA). All participants were evaluated for their body composition, RMR, and blood parameters. Result: Three nutrient patterns explaining 64% of the variance in dietary nutrients consumption were identified as B-complex-mineral, antioxidant, and unsaturated fatty acid and vitamin E (USFA-vit E) respectively. Participants were categorized into two groups based on the nutrient patterns. High scores of USFA-vit E pattern was significantly associated with the increase of RMR (β = 0.13, 95% CI = 0.79 to 68.16, p = 0.04). No significant associations were found among B-complex-mineral pattern (β = −0.00, 95% CI = −49.67 to 46.03, p = 0.94) and antioxidant pattern (β = 0.03, 95% CI −41.42 to 22.59, p = 0.56) with RMR. Conclusion: Our results suggested that the “USFA-vit E” pattern (such as PUFA, oleic, linoleic, vit.E, α-tocopherol and EPA) was associated with increased RMR.

scholarly journals ENERGY EXPENDITURE AND PHYSICAL ACTIVITY AMONG OLDER PARTICIPANTS FROM THE MULTICENTER AIDS COHORT STUDY (MACS)

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S549-S549
Author(s):  
Jennifer A Schrack ◽  
Todd T Brown ◽  
Joseph B Margolick
Keyword(s):  
Physical Activity ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Functional Decline ◽  
Time Of Day ◽  
Energy Utilization ◽  
Hiv Viral Load ◽  
Cross Sectional ◽  
And Function ◽  
Lower Physical Activity

Abstract Energy utilization becomes more inefficient with age and is linked to low physical activity and functional decline. Persons aging with HIV exhibit accelerated functional decline, but the effect of chronic HIV infection on energy utilization and free-living physical activity remains unclear. We investigated cross-sectional associations between age and: resting metabolic rate, peak walking energy (VO2), and 7-day physical activity by accelerometry in 100 men in the MACS (age: 60.8+/-6.8 years, 35% black, 46.1% HIV+, 94% virally suppressed). In multivariable regression models adjusted for age, BMI, race, chronic conditions, and HIV viral load, HIV+ men had a higher resting metabolic rate (β=103.2 kcals/day, p=0.03) and lower peak walking VO2 (β=-1.8 ml/kg/min, p<0.02) than HIV- men. Moreover, HIV+ men demonstrated lower physical activity, overall and by time of day (p<0.05). These results suggest that energy utilization differs by HIV serostatus, which may contribute to lower physical activity and function with aging.

The Relationship of Mode and Intensity of Training on Resting Metabolic Rate in Women

2001 ◽  
Vol 11 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Heidi K. Byrne ◽  
Jack H. Wilmore
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Women Subjects ◽  
Present Cross Sectional Study ◽  
Significant Difference ◽  
Level Of Training ◽  
The Relationship ◽  
Aerobically Trained

The present cross-sectional study was designed to investigate the relationship between exercise training and resting metabolic rate (RMR). The focus of this investigation was to compare RMR in aerobically trained (AT), resistance trained (RT), and untrained (UNT) women. Subjects were also classified as highly trained (HT), moderately trained (MT), or untrained (UNT) in order to examine the relationship between RMR and level of training. Sixty-one women between the ages of 18 and 46 years volunteered to serve as subjects in this study. Each subject completed measurements of body composition, maximal oxygen uptake (V̇O2max), and two consecutive measurements of RMR. The data presented show that there was no significant difference in resting metabolic rate between resistance-trained, aerobically trained, and control subjects. However, when grouped by intensity of training, there was a trend for an increased resting metabolic rate (kcal/day) in the highly trained subjects, regardless of mode of training.

scholarly journals Adherence to a Low Carbohydrate Diet may Modify Resting Metabolic Rate among Overweight and Obese Women

2020 ◽  
Author(s):  
Seyedeh Forough Sajjadi ◽  
Atieh Mirzababaei ◽  
nasim Ghodoosi ◽  
Sara Pooyan ◽  
Hana Arghavani ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Obese Women ◽  
Carbohydrate Diet ◽  
Cross Sectional ◽  
Low Carbohydrate Diet ◽  
Low Carbohydrate ◽  
Carb Diet ◽  
Adjusted Model

Abstract Objective Resting metabolic rate (RMR) accounts for most of the daily energy expenditure. The low-carb diet attenuates decreases in RMR. This study aims to investigate the relationship between a low-carb diet and resting metabolic rate status. Methods We enrolled 304 overweight and obese women in this cross-sectional study. BMI, fat mass, fat-free mass, visceral fat, insulin level were assessed. RMR was measured using indirect calorimetry. A low carbohydrate diet score was measured using a validated semi-quantitative food frequency questionnaire (FFQ). Results Our results showed no relationship between LCDS and DNR even after adjust for confounders (Inc. RMR: OR: 0.97; 95% CI: 0.92–1.01, P = 0.20; Dec. RMR: OR: 0.97; 95% CI: 0.94-1.00, P = 0.14). Some components of LCDS had significant differences with DNR, such as carbohydrate and Dec. RMR in adjusted model (OR: 1.62; 95% CI: 0.98–1.37, P = 0.08), MUFA and Dec. RMR in adjusted model (OR: 0.48; 95% CI: 0.21–1.10, P = 0.08) and refined grain and Inc. RMR in crude model (OR: 0.87; 95% CI: 0.77–0.99, P = 0.04). Conclusion Our study showed that there is no association between a low-carb diet and RMR status but carbohydrate, MUFA, and refined grain had a significant relationship.

scholarly journals Two Novel Models Evaluating the Determinants of Resting Metabolic Rate in Indian Children

2021 ◽  
Author(s):  
Sandra Aravind Areekal ◽  
Anuradha Khadilkar ◽  
Veena Ekbote ◽  
Neha Kajale ◽  
Arun S. Kinare ◽  
...  
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Childhood Development ◽  
Relative Mass ◽  
Kidney Volume ◽  
Indian Children ◽  
Cross Sectional ◽  
Multi Centre Study ◽  
The Mean

Abstract Resting metabolic rate (RMR) quantifies the minimal energy required to sustain vital body functions and is a crucial component of childhood development. While inter-individual variations in RMR have been studied for over a century they are poorly understood. Wang (Am. J. Hum., 2012) has modelled mean RMR per unit body mass (RMR/BM) in children grouped into age classes one year apart; this model is able to explain the variation in RMR/BM very accurately in a reference Caucasian dataset based on the relative masses of four major organs (liver, kidney, brain, heart) and the residual mass. However, it is not clear if it applies to other ethnicities, especially when the variation in the RMR is observed to be large in a population. Here we address the extent to which such a model can be adapted to explain RMR/BM in Indian children. Here we present two novel phenomenological models that describe the mean RMR/BM stratified by age in Indian children and adolescents, using data from the Multi-Centre Study (MCS) and RMR-USG. MCS is a cross-sectional dataset on 495 (235 girls) children aged 9 to 19 years with anthropometric, body composition and RMR measurements. RMR-USG consists of anthropometric data, RMR, and liver and kidney volume measured through ultrasonography in nine girls and nine boys aged 6 to 8 years. The mean RMR/BM in Indian children is observed to be significantly lower compared to their Caucasian counterparts, except in boys in the age groups 9 to 11 years and 12 to 13 years. The first is a modified Wang model in which the relative masses of four major organs are assumed to be uniformly lowered for Indian children. Theoretical predictions of size are not uniformly borne out in a pilot validation study, however, the relative mass of the kidney is indeed found to be significantly lower. We then present another version of the Wang model to demonstrate that changes in body composition alone can also explain the Indian data. Either model can be thus used phenomenologically to estimate mean RMR/BM by age in Indian children; however, understanding the mechanistic basis of variation in RMR/BM remains an open problem.

Relationship of resting metabolic rate to body composition and protein turnover

1990 ◽  
Vol 258 (6) ◽  
pp. E990-E998 ◽  
Author(s):  
S. Welle ◽  
K. S. Nair
Keyword(s):  
Protein Synthesis ◽  
Metabolic Rate ◽  
Protein Turnover ◽  
Resting Metabolic Rate ◽  
Whole Body ◽  
Simultaneous Estimation ◽  
Total Body Potassium ◽  
Average Value ◽  
Total Body ◽  
Relationship Of

This study examined whether variability among healthy young adults in resting metabolic rate, normalized for the amount of metabolically active tissue (assessed by total body potassium), is related to protein turnover. Resting metabolic rate was measured by indirect calorimetry for 2 h in 26 men and 21 women, 19-33 yr old, with simultaneous estimation of protein turnover during a 4-h infusion of L-[1-13C]leucine. After adjusting metabolic rate for total body potassium, the standard deviation was only 89 kcal/day, or 5.5% of the average value. There was a high correlation between leucine flux (an index of proteolysis) and metabolic rate (r = 0.84) and between the nonoxidized portion of leucine flux (an index of protein synthesis) and metabolic rate (r = 0.83). This relationship was weaker, but still significant, after adjusting leucine metabolism and metabolic rate for total body potassium (r = 0.36 for leucine flux vs. metabolic rate, r = 0.33 for nonoxidized portion of leucine flux vs. metabolic rate, P less than 0.05). The regression analysis suggested that the contribution of protein turnover to resting metabolic rate was approximately 20% in an average subject. Metabolic rate and protein turnover were highest in the subjects with the greatest amount of body fat, even after accounting for differences in whole body potassium. Neither resting metabolic rate nor protein turnover was related to total or free concentrations of thyroxine or triiodothyronine, within the euthyroid range.(ABSTRACT TRUNCATED AT 250 WORDS)

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