scholarly journals Whole-Body MRI and Ethnic Differences in Adipose Tissue and Skeletal Muscle Distribution in Overweight Black and White Adolescent Boys

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
SoJung Lee ◽  
YoonMyung Kim ◽  
Jennifer L. Kuk ◽  
Fernando E. Boada ◽  
Silva Arslanian
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Ethnic Differences ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Black Boys ◽  
Lower Body ◽  
White Youth ◽  
Whole Body Mri ◽  
Black And White

It is unclear whether ethnic differences exist in adipose tissue (AT) and skeletal muscle (SM) distribution in black and white youth. Investigation into the pattern of AT and SM distribution in black versus white youth may provide insight into the previously reported health disparities between these ethnicities. Therefore, we examined total and regional AT and SM in overweight black and white boys. The study sample included overweight black (n=19) and white (n=21) boys (11–18 yr, BMI ≥ 85th) whose body composition was evaluated using whole-body MRI. Despite similar age, Tanner stage, and BMI, black boys had significantly (P<.05) less visceral AT than white boys and more (P<.05) total and lower-body subcutaneous AT (SAT) in both absolute (kg) and relative (%) terms. There was a main effect (P<.05) of ethnicity on the relationship between total and regional AT, such that for a given amount of total body AT (kg), black boys had a greater (P<.05) lower-body SAT and less visceral AT than their white peers. For a given amount of total SM, black boys had more (P<.05) SM in the thigh. Compared with overweight white boys, overweight black boys have less visceral fat, more subcutaneous fat, and more thigh skeletal muscle.

Influence of Free Fatty Acid Concentrations and Weight Loss on Adipose Tissue Direct Free Fatty Acid Storage Rates

2021 ◽  
Author(s):  
Qingyi Jia ◽  
B Gisella Carranza Leon ◽  
Michael D Jensen
Keyword(s):  
Weight Loss ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Subcutaneous Fat ◽  
Premenopausal Women ◽  
Tissue Level ◽  
Research Unit ◽  
Lower Body ◽  
Plasma Ffa

Abstract Context The factors that determine the recycling of free fatty acids (FFA) back into different adipose tissue depots via the direct storage pathway are not completely understood. Objective To assess the interactions between adipocyte factors and plasma FFA concentrations that determine regional FFA storage rates. Design We measured direct adipose tissue FFA storage rates before and after weight loss under high FFA (intravenous somatostatin and epinephrine) and low (intravenous insulin and glucose) FFA concentrations. Setting Mayo Clinic Clinical Research Unit. Patients Sixteen premenopausal women, BMI 30 - 37 kg/m 2. Intervention Comprehensive lifestyle weight loss program. Main Outcome Measure Direct FFA storage rates in upper and lower body subcutaneous fat. Results Over the entire range of FFA and under isolated conditions of elevated FFA concentrations the storage rates of FFA into upper and lower body subcutaneous fat per unit lipid were associated with concentrations, not adipocyte fatty acid storage factors. Under low FFA conditions, direct FFA storage rates were related to adipocyte CD36 content, not tissue level content of fatty acid storage factors. Weight loss did not change these relationships. Conclusions The regulation of direct FFA storage under low FFA concentration conditions appears to be at the level of the cell/adipocyte content of CD36, whereas under high FFA concentration conditions direct FFA storage at the tissue level is predicted by plasma FFA concentrations, independent of adipocyte size or fatty acid storage factors. These observations offer novel insights into how adipose tissue regulates direct FFA storage in humans.

Reduced plasma FFA availability increases net triacylglycerol degradation, but not GPAT or HSL activity, in human skeletal muscle

2004 ◽  
Vol 287 (1) ◽  
pp. E120-E127 ◽  
Author(s):  
Matthew J. Watt ◽  
Anna G. Holmes ◽  
Gregory R. Steinberg ◽  
Jose L. Mesa ◽  
Bruce E. Kemp ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Body Fat ◽  
Plasma Free Fatty Acid ◽  
Fat Oxidation ◽  
Dry Mass ◽  
Hormone Sensitive Lipase ◽  
Whole Body ◽  
Plasma Ffa

Intramuscular triacylglycerols (IMTG) are proposed to be an important metabolic substrate for contracting muscle, although this remains controversial. To test the hypothesis that reduced plasma free fatty acid (FFA) availability would increase IMTG degradation during exercise, seven active men cycled for 180 min at 60% peak pulmonary O2 uptake either without (CON) or with (NA) prior ingestion of nicotinic acid to suppress adipose tissue lipolysis. Skeletal muscle and adipose tissue biopsy samples were obtained before and at 90 and 180 min of exercise. NA ingestion decreased ( P < 0.05) plasma FFA at rest and completely suppressed the exercise-induced increase in plasma FFA (180 min: CON, 1.42 ± 0.07; NA, 0.10 ± 0.01 mM). The decreased plasma FFA during NA was associated with decreased ( P < 0.05) adipose tissue hormone-sensitive lipase (HSL) activity (CON: 13.9 ± 2.5, NA: 9.1 ± 3.0 nmol·min−1·mg protein−1). NA ingestion resulted in decreased whole body fat oxidation and increased carbohydrate oxidation. Despite the decreased whole body fat oxidation, net IMTG degradation was greater in NA compared with CON (net change: CON, 2.3 ± 0.8; NA, 6.3 ± 1.2 mmol/kg dry mass). The increased IMTG degradation did not appear to be due to reduced fatty acid esterification, because glycerol 3-phosphate activity was not different between trials and was unaffected by exercise (rest: 0.21 ± 0.07; 180 min: 0.17 ± 0.04 nmol·min−1·mg protein−1). HSL activity was not increased from resting rates during exercise in either trial despite elevated plasma epinephrine, decreased plasma insulin, and increased ERK1/2 phosphorylation. AMP-activated protein kinase (AMPK)α1 activity was not affected by exercise or NA, whereas AMPKα2 activity was increased ( P < 0.05) from rest during exercise in NA and was greater ( P < 0.05) than in CON at 180 min. These data suggest that plasma FFA availability is an important mediator of net IMTG degradation, and in the absence of plasma FFA, IMTG degradation cannot maintain total fat oxidation. These changes in IMTG degradation appear to disassociate, however, from the activity of the key enzymes responsible for synthesis and degradation of this substrate.

Metabolic adaptations in skeletal muscle, adipose tissue, and whole-body oxidative capacity in response to resistance training

2014 ◽  
Vol 114 (7) ◽  
pp. 1463-1471 ◽  
Author(s):  
Malin Alvehus ◽  
Niklas Boman ◽  
Karin Söderlund ◽  
Michael B. Svensson ◽  
Jonas Burén
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Resistance Training ◽  
Oxidative Capacity ◽  
Whole Body ◽  
Metabolic Adaptations

Thermogenic response to epinephrine in the forearm and abdominal subcutaneous adipose tissue

1992 ◽  
Vol 263 (5) ◽  
pp. E850-E855 ◽  
Author(s):  
L. Simonsen ◽  
J. Bulow ◽  
J. Madsen ◽  
N. J. Christensen
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Energy Expenditure ◽  
Oxygen Uptake ◽  
Glucose Uptake ◽  
Subcutaneous Adipose Tissue ◽  
Whole Body ◽  
Epinephrine Infusion ◽  
Basal Period ◽  
Subcutaneous Adipose

Whole body energy expenditure, thermogenic and metabolic changes in the forearm, and intercellular glucose concentrations in subcutaneous adipose tissue on the abdomen determined by microdialysis were measured during epinephrine infusion in healthy subjects. After a control period, epinephrine was infused at rates of 0.2 and 0.4 nmol.kg-1 x min-1. Whole body resting energy expenditure was 4.36 +/- 0.56 (SD) kJ/min. Energy expenditure increased to 5.14 +/- 0.74 and 5.46 +/- 0.79 kJ/min, respectively (P < 0.001), during the epinephrine infusions. Respiratory exchange ratio was 0.80 +/- 0.04 in the resting state and did not change. Local forearm oxygen uptake was 3.9 +/- 1.3 mumol.100 g-1 x min-1 in the basal period. During epinephrine infusion, it increased to 5.8 +/- 2.1 (P < 0.03) and 7.5 +/- 2.3 mumol.100 g-1 x min-1 (P < 0.001). Local forearm glucose uptake was 0.160 +/- 0.105 mumol.100 g-1 x min-1 and increased to 0.586 +/- 0.445 and 0.760 +/- 0.534 mumol.100 g-1 x min-1 (P < 0.025). The intercellular glucose concentration in the subcutaneous adipose tissue on the abdomen was equal to the arterial concentration in the basal period but did not increase as much during infusion of epinephrine, indicating glucose uptake in adipose tissue in this condition. If it is assumed that forearm skeletal muscle is representative for the average skeletal muscle, it can be calculated that on average 40% of the enhanced whole body oxygen uptake induced by infusion of epinephrine is taking place in skeletal muscle. It is proposed that adipose tissue may contribute to epinephrine-induced thermogenesis.

Influence of diet and exercise on skeletal muscle and visceral adipose tissue in men

1996 ◽  
Vol 81 (6) ◽  
pp. 2445-2455 ◽  
Author(s):  
Robert Ross ◽  
John Rissanen ◽  
Heather Pedwell ◽  
Jennifer Clifford ◽  
Peter Shragge
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
Whole Body ◽  
Relative Reduction ◽  
Body Regions ◽  
Diet And Exercise ◽  
Magnetic Resonance Imaging Mri ◽  
Visceral Adipose

Ross, Robert, John Rissanen, Heather Pedwell, Jennifer Clifford, and Peter Shragge. Influence of diet and exercise on skeletal muscle and visceral adipose tissue in men. J. Appl. Physiol. 81(6): 2445–2455, 1996.—The effects of diet only (DO) and diet combined with either aerobic (DA) or resistance (DR) exercise on subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), lean tissue (LT), and skeletal muscle (SM) tissue were evaluated in 33 obese men (DO, n= 11; DA, n = 11; DR, n = 11). All tissues were measured by using a whole body multislice magnetic resonance imaging (MRI) model. Within each group, significant reductions were observed for body weight, SAT, and VAT ( P < 0.05). The reductions in body weight (∼10%) and SAT (∼25%) and VAT volume (∼35%) were not different between groups ( P > 0.05). For all treatments, the relative reduction in VAT was greater than in SAT ( P < 0.05). For the DA and DR groups only, the reduction in abdominal SAT (∼27%) was greater ( P < 0.05) than that observed for the gluteal-femoral region (∼20%). Conversely, the reduction in VAT was uniform throughout the abdomen regardless of treatment ( P > 0.05). MRI-LT and MRI-SM decreased both in the upper and lower body regions for the DO group alone ( P < 0.05). Peak O2 uptake (liters) was significantly improved (∼14%) in the DA group as was muscular strength (∼20%) in the DR group ( P< 0.01). These findings indicate that DA and DR result in a greater preservation of MRI-SM, mobilization of SAT from the abdominal region, by comparison with the gluteal-femoral region, and improved functional capacity when compared with DO in obese men.

Insulin resistance: cross-talk between adipose tissue and skeletal muscle, through free fatty acids, liver X receptor, and peroxisome proliferator-activated receptor-α signaling

2013 ◽  
Vol 15 (3) ◽  
Author(s):  
Ann Louise Olson
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Glucose Homeostasis ◽  
Glucose Transporter ◽  
Control Point ◽  
Nuclear Hormone Receptor ◽  
Whole Body ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

AbstractSkeletal muscle and adipose tissue play a major role in the regulation of whole-body glucose homeostasis. Much of the coordinated regulation of whole-body glucose homeostasis results from the regulation of lipid storage and release by adipose tissue and efficient switching between glucose oxidation and fatty acid oxidation in skeletal muscle. A control point for these biochemical actions center around the regulation of the insulin responsive glucose transporter, GLUT4. This review examines the regulation of GLUT4 in adipose tissue and skeletal muscle, in the context of the steroid nuclear hormone receptor signaling.

Total body skeletal muscle and adipose tissue volumes: estimation from a single abdominal cross-sectional image

2004 ◽  
Vol 97 (6) ◽  
pp. 2333-2338 ◽  
Author(s):  
Wei Shen ◽  
Mark Punyanitya ◽  
ZiMian Wang ◽  
Dympna Gallagher ◽  
Marie-Pierre St.-Onge ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Mass Index ◽  
Adipose Tissue ◽  
Magnetic Resonance ◽  
Body Mass ◽  
Whole Body ◽  
Intervertebral Space ◽  
Cross Sectional ◽  
Abdominal Image ◽  
Total Body

A single abdominal cross-sectional computerized axial tomography and magnetic resonance image is often obtained in studies examining adipose tissue (AT) distribution. An abdominal image might also provide additional useful information on total body skeletal muscle (SM) and AT volumes with related physiological insights. We therefore investigated the relationships between abdominal SM and AT areas from single images and total body component volumes in a large and diverse sample of healthy adult subjects. Total body SM and AT volumes were derived by whole body multislice magnetic resonance imaging in 123 men [age (mean ± SD) of 41.6 ± 15.8 yr; body mass index of 25.9 ± 3.4 kg/m2] and 205 women (age of 47.8 ± 18.7 yr; body mass index of 26.7 ± 5.6 kg/m2). Single abdominal SM and AT slice areas were highly correlated with total body SM ( r = 0.71–0.92; r = 0.90 at L4–L5 intervertebral space) and AT ( r = 0.84–0.96; r = 0.94 at L4–L5 intervertebral space) volumes, respectively. R2 increased by only 5.7–6.1% for SM and 2.7–4.4% for AT with the inclusion of subject sex, age, ethnicity, scanning position, body mass index, and waist circumference in the model. The developed SM and AT models were validated in an additional 49 subjects. To achieve equivalent power to a study measuring total body SM or AT volumes, a study using a single abdominal image would require 17–24% more subjects for SM and 6–12% more subjects for AT. Measurement of a single abdominal image can thus provide estimates of total body SM and AT for group studies of healthy adults.

Skeletal muscle mass and distribution in 468 men and women aged 18–88 yr

2000 ◽  
Vol 89 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Ian Janssen ◽  
Steven B. Heymsfield ◽  
ZiMian Wang ◽  
Robert Ross
Keyword(s):  
Skeletal Muscle ◽  
Gender Differences ◽  
Body Weight ◽  
Upper Body ◽  
Whole Body ◽  
Lower Body ◽  
Large Measure ◽  
Imaging Protocol ◽  
Men And Women ◽  
Magnetic Resonance Imaging Protocol

We employed a whole body magnetic resonance imaging protocol to examine the influence of age, gender, body weight, and height on skeletal muscle (SM) mass and distribution in a large and heterogeneous sample of 468 men and women. Men had significantly ( P < 0.001) more SM in comparison to women in both absolute terms (33.0 vs. 21.0 kg) and relative to body mass (38.4 vs. 30.6%). The gender differences were greater in the upper (40%) than lower (33%) body ( P < 0.01). We observed a reduction in relative SM mass starting in the third decade; however, a noticeable decrease in absolute SM mass was not observed until the end of the fifth decade. This decrease was primarily attributed to a decrease in lower body SM. Weight and height explained ∼50% of the variance in SM mass in men and women. Although a linear relationship existed between SM and height, the relationship between SM and body weight was curvilinear because the contribution of SM to weight gain decreased with increasing body weight. These findings indicate that men have more SM than women and that these gender differences are greater in the upper body. Independent of gender, aging is associated with a decrease in SM mass that is explained, in large measure, by a decrease in lower body SM occurring after the fifth decade.

Exercise without weight loss is an effective strategy for obesity reduction in obese individuals with and without Type 2 diabetes

2005 ◽  
Vol 99 (3) ◽  
pp. 1220-1225 ◽  
Author(s):  
SoJung Lee ◽  
Jennifer L. Kuk ◽  
Lance E. Davidson ◽  
Robert Hudson ◽  
Katherine Kilpatrick ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Weight Loss ◽  
Visceral Fat ◽  
Subcutaneous Fat ◽  
Substantial Reduction ◽  
Whole Body ◽  
Moderate Intensity ◽  
Regional Body Composition

It is unclear whether chronic exercise without caloric restriction or weight loss is a useful strategy for obesity reduction in obese men with and without Type 2 diabetes (T2D). We examined the effects of exercise without weight loss on total and regional adiposity and skeletal muscle mass and composition in lean men and in obese men with and without T2D. Twenty-four men participated in 13 wk of supervised aerobic exercise, five times per week for 60 min at a moderate intensity (∼60% peak oxygen uptake). Total and regional body composition was measured by magnetic resonance imaging. Skeletal muscle composition was determined using computed tomography. Cardiorespiratory fitness was assessed using a graded maximal treadmill test. Body weight did not change within any group in response to exercise ( P > 0.1). Significant reductions in total, abdominal subcutaneous, and visceral fat were observed within each group ( P < 0.01). The reduction in total and abdominal subcutaneous fat was not different ( P > 0.1) between groups; however, the reduction in visceral fat was greater ( P < 0.01) in the obese and T2D groups by comparison to the lean group. A significant ( P < 0.01) increase in total skeletal muscle, high-density muscle area, and mean muscle attenuation was observed independent of group, and these changes were not different between groups ( P > 0.1). Accordingly, whole body fat-to-muscle ratio was increased ( P < 0.01) independent of groups. In conclusion, regular exercise without weight loss is associated with a substantial reduction in total and visceral fat and in skeletal muscle lipid in both obesity and T2D.

Biology of upper-body and lower-body adipose tissue—link to whole-body phenotypes

2014 ◽  
Vol 11 (2) ◽  
pp. 90-100 ◽  
Author(s):  
Fredrik Karpe ◽  
Katherine E. Pinnick
Keyword(s):  
Adipose Tissue ◽  
Upper Body ◽  
Whole Body ◽  
Lower Body
Sign in / Sign up

Export Citation Format

Share Document