scholarly journals Genetic and environmental influences on skeletal muscle phenotypes as a function of age and sex in large, multigenerational families of African heritage

2007 ◽  
Vol 103 (4) ◽  
pp. 1121-1127 ◽  
Author(s):  
Steven J. Prior ◽  
Stephen M. Roth ◽  
Xiaojing Wang ◽  
Candace Kammerer ◽  
Iva Miljkovic-Gacic ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Lean Mass ◽  
Genetic Correlations ◽  
Cross Sectional Area ◽  
Calf Muscle ◽  
Sectional Area ◽  
Cross Sectional ◽  
African Heritage ◽  
Genetic Components ◽  
Muscle Cross Sectional Area

The aim of this study was to estimate the heritability of and environmental contributions to skeletal muscle phenotypes (appendicular lean mass and calf muscle cross-sectional area) in subjects of African descent and to determine whether heritability estimates are impacted by sex or age. Body composition was measured by dual-energy X-ray absorptiometry and computed tomography in 444 men and women aged 18 yr and older (mean: 43 yr) from eight large, multigenerational Afro-Caribbean families (family size range: 21–112). Using quantitative genetic methods, we estimated heritability and the association of anthropometric, lifestyle, and medical variables with skeletal muscle phenotypes. In the overall group, we estimated the heritability of lean mass and calf muscle cross-sectional area (h2 = 0.18–0.23, P < 0.01) and contribution of environmental factors to these phenotypes ( r2 = 0.27–0.55, P < 0.05). In our age-specific analysis, the heritability of leg lean mass was lower in older vs. younger individuals (h2 = 0.05 vs. 0.23, respectively, P = 0.1). Sex was a significant covariate in our models ( P < 0.001), although sex-specific differences in heritability varied depending on the lean mass phenotype analyzed. High genetic correlations (ρG = 0.69–0.81; P < 0.01) between different lean mass measures suggest these traits share a large proportion of genetic components. Our results demonstrate the heritability of skeletal muscle traits in individuals of African heritage and that heritability may differ as a function of sex and age. As the loss of skeletal muscle mass is related to metabolic abnormalities, disability, and mortality in older individuals, further research is warranted to identify specific genetic loci that contribute to these traits in general and in a sex- and age-specific manner.

Anthropometric Prediction of Skeletal Muscle Cross-sectional Area in Persons with Spinal Cord Injury

2016 ◽  
Vol 48 ◽  
pp. 894
Author(s):  
Rodney C. Wade ◽  
Ashraf S. Gorgey ◽  
Jennifer Hubert ◽  
Ryan Sumrell ◽  
Justin Bengel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Cord Injury ◽  
Muscle Cross Sectional Area

Relationship Between Calf Muscle Size and Strength after Achilles Rupture Repair

2000 ◽  
Vol 21 (4) ◽  
pp. 330-335 ◽  
Author(s):  
J. Leppilahti ◽  
S. Lähde ◽  
K. Forsman ◽  
J. Kangas ◽  
K. Kauranen ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Achilles Tendon Rupture ◽  
Peak Torque ◽  
Cross Sectional Area ◽  
Calf Muscle ◽  
Muscle Size ◽  
Sectional Area ◽  
Unaffected Side ◽  
Cross Sectional ◽  
Muscle Cross Sectional Area

The object was to study the relationships between calf muscle size and strength in 85 patients an average of 3.1 years after repair of achilles tendon rupture. The isokinetic calf muscle strength results were excellent or good for 73 % of the patients, whereas calf muscle size was normal in only 30 %. The average plantar flexion peak torque per unit muscle cross-sectional area was higher on the injured side than on the uninjured side. The average calf muscle cross-sectional area deficit was 15±9% (p<0.001) of that on the unaffected side, while the average plantar flexion peak torque deficit was speed-dependent, being 9±18%, 10±18 and 2±13% of that on the unaffected side at 30, 90, and 2407sec (p<0.001). The correlation between cross-sectional area and peak torque varied in the range 0.52–0.61 at 30, 90 and 2407sec (p<0.001).

scholarly journals A Comparison of Techniques for Estimating and Detecting Changes in Skeletal Muscle Cross-Sectional Area

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 945
Author(s):  
Johnathon H. Moore ◽  
Cody T. Haun ◽  
Emily L. Grandprey ◽  
Katelyn P. Joubert ◽  
Christopher G. Vann ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Comparison Of Techniques ◽  
Muscle Cross Sectional Area

Effect of acute head-down tilt on skeletal muscle cross-sectional area and proton transverse relaxation time

1996 ◽  
Vol 81 (4) ◽  
pp. 1572-1577 ◽  
Author(s):  
Michael S. Conley ◽  
Jeanne M. Foley ◽  
Lori L. Ploutz-Snyder ◽  
Ronald A. Meyer ◽  
Gary A. Dudley
Keyword(s):  
Skeletal Muscle ◽  
Relaxation Time ◽  
Transverse Relaxation Time ◽  
Cross Sectional Area ◽  
Neck Muscle ◽  
Upright Posture ◽  
Sectional Area ◽  
Cross Sectional ◽  
Transverse Relaxation ◽  
Muscle Cross Sectional Area

Conley, Michael S., Jeanne M. Foley, Lori L. Ploutz-Snyder, Ronald A. Meyer, and Gary A. Dudley. Effect of acute head-down tilt on skeletal muscle cross-sectional area and proton transverse relaxation time. J. Appl. Physiol.81(4): 1572–1577, 1996.—This study investigated changes in skeletal muscle cross-sectional area (CSA) evoked by fluid shifts that accompany short-term 6° head-down tilt (HDT) or horizontal bed rest, the time course of the resolution of these changes after resumption of upright posture, and the effect of altered muscle CSA, in the absence of increased contractile activity, on proton transverse relaxation time (T2). Average muscle CSA and T2 were determined by standard spin-echo magnetic resonance imaging. Analyses were performed on contiguous transaxial images of the neck and calf. After a day of normal activity, 24 h of HDT increased neck muscle CSA 19 ± 4 (SE)% ( P < 0.05) while calf muscle CSA decreased 14 ± 3% ( P < 0.05). The horizontal posture (12 h) induced about one-half of these responses: an 11 ± 2% ( P < 0.05) increase in neck muscle CSA and an 8 ± 2% decrease ( P < 0.05) in the calf. Within 2 h after resumption of upright posture, neck and calf muscle CSA returned to within 0.5% ( P > 0.05) of the values assessed after a day of normal activity, with most of the change occurring within the first 30 min. No further change in muscle CSA was observed through 6 h of upright posture. Despite these large alterations in muscle CSA, T2 was not altered by more than 1.1 ± 0.6% ( P > 0.05) and did not relate to muscle size. These results suggest that postural manipulations and subsequent fluid shifts modeling microgravity elicit marked changes in muscle size. Because these responses were not associated with alterations in muscle T2, it does not appear that simple movement of water into muscle can explain the contrast shift observed after exercise.

scholarly journals Overexpression of HSP10 in skeletal muscle of transgenic mice prevents the age-related fall in maximum tetanic force generation and muscle cross-sectional area

2010 ◽  
Vol 299 (1) ◽  
pp. R268-R276 ◽  
Author(s):  
Anna C. Kayani ◽  
Graeme L. Close ◽  
Wolfgang H. Dillmann ◽  
Ruben Mestril ◽  
Malcolm J. Jackson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Cross Sectional Area ◽  
Force Generation ◽  
Sectional Area ◽  
Wild Type ◽  
Cross Sectional ◽  
Tetanic Force ◽  
Age Related ◽  
Muscle Cross Sectional Area

Skeletal muscle atrophy and weakness are major contributors to frailty and impact significantly on quality of life of older people. Muscle aging is characterized by a loss of maximum tetanic force (Po) generation, primarily due to muscle atrophy, to which mitochondrial dysfunction is hypothesized to contribute. We hypothesized that lifelong overexpression of the mitochondrial heat shock protein (HSP) HSP10 in muscle of mice would protect against development of these deficits. Po generation by extensor digitorum longus muscles of adult and old wild-type and HSP10-overexpressing mice was determined in situ. Muscles were subjected to damaging lengthening contractions, and force generation was remeasured at 3 h or 28 days to examine susceptibility to, and recovery from, damage, respectively. Muscles of old wild-type mice had a 23% deficit in Po generation and a 10% deficit in muscle cross-sectional area compared with muscles of adult wild-type mice. Overexpression of HSP10 prevented this age-related fall in Po generation and reduction in cross-sectional area observed in muscles of old wild-type mice. Additionally, overexpression of HSP10 protected against contraction-induced damage independent of age but did not improve recovery if damage occurred. Preservation of muscle force generation and CSA by HSP10 overexpression was associated with protection against the age-related accumulation of protein carbonyls. Data demonstrate that development of age-related muscle weakness may not be inevitable and show, for the first time, that lifelong overexpression of an HSP prevents the age-related loss of Po generation. These findings support the hypothesis that mitochondrial dysfunction is involved in the development of age-related muscle deficits.

OR37: Psoas Versus Whole L3 Skeletal Muscle Cross-Sectional Area: How Do They Relate?

2019 ◽  
Vol 38 ◽  
pp. S18
Author(s):  
K. Rollins ◽  
A. Gopinath ◽  
A. Awwad ◽  
I. Macdonald ◽  
D.N. Lobo
Keyword(s):  
Skeletal Muscle ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Muscle Cross Sectional Area
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