scholarly journals Changes in fat and skeletal muscle with exercise training in obese adolescents: Comparison of whole-body MRI and dual energy X-ray absorptiometry

Obesity ◽  
2013 ◽  
Vol 21 (10) ◽  
pp. 2063-2071 ◽  
Author(s):  
SoJung Lee ◽  
Jennifer L. Kuk
1996 ◽  
Vol 80 (3) ◽  
pp. 824-831 ◽  
Author(s):  
Z. M. Wang ◽  
M. Visser ◽  
R. Ma ◽  
R. N. Baumgartner ◽  
D. Kotler ◽  
...  

Although skeletal muscle (SM) is a major body component, whole body measurement methods remain limited and inadequately investigated. The aim of the present study was to evaluate the Burkinshaw in vivo neutron activation analysis (IVNA)-whole body 40K-counting and dual-energy X-ray absorptiometry (DXA) methods of estimating SM by comparison to adipose tissue-free SM measured using multiscan computerized axial tomography (CT). In the Burkinshaw method the potassium-to-nitrogen ratios of SM and non-SM lean tissue are assumed constant; in the DXA method the ratio of appendicular SM to total SM is assumed constant at 0.75. Seventeen healthy men [77.5 +/- 13.8 (SD) kg body wt] and eight men with acquired immunodeficiency syndrome (AIDS; 65.5 +/- 7.6 kg) completed CT, IVNA, and DXA studies. SM measured by CT was 34.4 +/- 6.2 kg for the healthy subjects and 27.2 +/- 4.0 kg for the AIDS patients. Compared with CT, the Burkinshaw method underestimated SM by an average of 6.9 kg (20.1%, P = 0.0001) and 6.3 kg (23.2%, P = 0.01) in the healthy men and the men with AIDS, respectively. The DXA method minimally overestimated SM in both groups (2.0 kg and 5.8% in healthy men, P = 0.001; 1.4 kg and 5.1% in men with AIDS, P = 0.16). This overestimate could be explained by a higher actual than assumed ratio of DXA-measured appendicular SM to total body SM (actual = 0.79 +/- 0.05, assumed = 0.75). The current study results reveal that large errors are present in the Burkinshaw SM method and that substantial refinements in the models that form the basis of this IVNA approach are needed. The model on which the DXA-SM method is based also needs further minor refinements, but this is a promising in vivo approach because of less radiation exposure and lower cost than the IVNA and CT methods.


2004 ◽  
Vol 97 (2) ◽  
pp. 655-660 ◽  
Author(s):  
Jaehee Kim ◽  
Stanley Heshka ◽  
Dympna Gallagher ◽  
Donald P. Kotler ◽  
Laurel Mayer ◽  
...  

Skeletal muscle (SM) is a large and physiologically important compartment. Adipose tissue is found interspersed between and within SM groups and is referred to as intermuscular adipose tissue (IMAT). The study objective was to develop prediction models linking appendicular lean soft tissue (ALST) estimates by dual-energy X-ray absorptiometry (DXA) with whole body IMAT-free SM quantified by magnetic resonance imaging. ALST and total-body IMAT-free SM were evaluated in 270 healthy adults [body mass index (BMI) of <35 kg/m2]. The SM prediction models were then validated by the leave-one-out method and by application in a new group of subjects who varied in SM mass [anorexia nervosa (AN), n = 23; recreational athletes, n = 16; patients with acromegaly, n = 7]. ALST alone was highly correlated with whole body IMAT-free SM [ model 1: R2 = 0.96, standard error (SE) = 1.46 kg, P < 0.001]; age ( model 2: R2 = 0.97, SE = 1.38 kg, P < 0.001) and sex and race ( model 3: R2 = 0.97, SE = 1.06 kg, both P < 0.001) added significantly to the prediction models. All three models validated in the athletes and patients with acromegaly but significantly ( P < 0.01–0.001) over-predicted SM in the AN group as a whole. However, model 1 was validated in AN patients with BMIs in the model-development group range ( n = 11; BMI of >16 kg/m2) but not in those with a BMI of <16 kg/m2 ( n = 12). The DXA-based models are accurate for predicting IMAT-free SM in selected populations and thus provide a new opportunity for quantifying SM in physiological and epidemiological investigations.


1986 ◽  
Vol 250 (5) ◽  
pp. E570-E575
Author(s):  
G. K. Grimditch ◽  
R. J. Barnard ◽  
S. A. Kaplan ◽  
E. Sternlicht

We examined the hypothesis that the exercise training-induced increase in skeletal muscle insulin sensitivity is mediated by adaptations in insulin binding to sarcolemmal (SL) insulin receptors. Insulin binding studies were performed on rat skeletal muscle SL isolated from control and trained rats. No significant differences were noted between groups in body weight or fat. An intravenous glucose tolerance test showed an increase in whole-body insulin sensitivity with training, and specific D-glucose transport studies on isolated SL vesicles indicated that this was due in part to adaptations in skeletal muscle. Enzyme marker analyses revealed no differences in yield, purity, or contamination of SL membranes between the two groups. Scatchard analyses indicated no significant differences in the number of insulin binding sites per milligram SL protein on the high-affinity (15.0 +/- 4.1 vs. 18.1 +/- 6.4 X 10(9)) or on the low-affinity portions (925 +/- 80 vs. 884 +/- 106 X 10(9)) of the curves. The association constants of the high-affinity (0.764 +/- 0.154 vs. 0.685 +/- 0.264 X 10(9) M-1) and of the low affinity sites (0.0096 +/- 0.0012 vs. 0.0102 +/- 0.0012 X 10(9) M-1) also were similar. These results do not support the hypothesis that the increased sensitivity to insulin after exercise training is due to changes in SL insulin receptor binding.


2018 ◽  
Vol 124 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Richard V. Clark ◽  
Ann C. Walker ◽  
Ram R. Miller ◽  
Robin L. O’Connor-Semmes ◽  
Eric Ravussin ◽  
...  

A noninvasive method to estimate muscle mass based on creatine ( methyl-d3) (D3-creatine) dilution using fasting morning urine was evaluated for accuracy and variability over a 3- to 4-mo period. Healthy older (67- to 80-yr-old) subjects ( n = 14) with muscle wasting secondary to aging and four patients with chronic disease (58–76 yr old) fasted overnight and then received an oral 30-mg dose of D3-creatine at 8 AM ( day 1). Urine was collected during 4 h of continued fasting and then at consecutive 4- to 8-h intervals through day 5. Assessment was repeated 3–4 mo later in 13 healthy subjects and 1 patient with congestive heart failure. Deuterated and unlabeled creatine and creatinine were measured using liquid chromatography–tandem mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by whole body MRI and 24-h urine creatinine, and lean body mass (LBM) was measured by dual-energy X-ray absorptiometry (DXA). D3-creatinine urinary enrichment from day 5 provided muscle mass estimates that correlated with MRI for all subjects ( r = 0.88, P < 0.0001), with less bias [difference from MRI = −3.00 ± 2.75 (SD) kg] than total LBM assessment by DXA, which overestimated muscle mass vs. MRI (+22.5 ± 3.7 kg). However, intraindividual variability was high with the D3-creatine dilution method, with intrasubject SD for estimated muscle mass of 2.5 kg vs. MRI (0.5 kg) and DXA (0.8 kg). This study supports further clinical validation of the D3-creatine method for estimating muscle mass. NEW & NOTEWORTHY Measurement of creatine ( methyl-d3) (D3-creatine) and D3-creatinine excretion in fasted morning urine samples may be a simple, less costly alternative to MRI or dual-energy X-ray absorptiometry (DXA) to calculate total body muscle mass. The D3-creatine enrichment method provides estimates of muscle mass that correlate well with MRI, and with less bias than DXA. However, intraindividual variability is high with the D3-creatine method. Studies to refine the spot urine sample method for estimation of muscle mass may be warranted.


Author(s):  
A. V. Naumov ◽  
D. V. Demenok ◽  
Yu. S. Onuchina ◽  
N. O. Khovasova ◽  
V. I. Moroz ◽  
...  

Osteoporosis and sarcopenia are age-associated diseases of the musculoskeletal system. Osteosarcopenia, the presence of osteopenia/osteoporosis and sarcopenia. The prevalence of osteosarcopenia in older adults with failing was 37% and associated with higher rate of death. Diagnosis of osteosarcopenia consists of describing medical history of fractures, providing x-ray of the spine (if it is needed) and bone densitometry, calculation of Fracture Risk Assessment Tool (FRAX), evaluating muscle strength, mass, function. The most common exam which is used to measure bone mineral density (BMD) is dual-energy x-ray absorptiometry (DXA or DEXA). Screening using the FRAX is recommended in all postmenopausal women and mеn over 50 in order to identify individuals with high probability of fractures. It is recommended to diagnose osteoporosis in patients with fragility fracture of large bones of the skeleton. Diagnosis of sarcopenia is consist of measures for three parameters: muscle strength, muscle quantity/quality and physical performance as an indicator of severity. Muscle strength can be measured with carpal dynamometry. Muscle mass can be evaluated dual-energy X-ray absorptiometry (program «Whole body»). Muscle function can be evaluated with short physical performance battery (SPPB) tests. In this article described algorithm of diagnosis of osteosarcopenia.


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