scholarly journals Muscle fiber-type distribution predicts weight gain and unfavorable left ventricular geometry: a 19 year follow-up study

2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Jouko Karjalainen ◽  
Heikki Tikkanen ◽  
Miika Hernelahti ◽  
Urho M Kujala
Keyword(s):  
Weight Gain ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Left Ventricular ◽  
Left Ventricular Geometry ◽  
Type Distribution ◽  
Ventricular Geometry ◽  
Follow Up Study ◽  
Fiber Type Distribution

Abstract 3634: Association of Weight Loss and Changes in Left Ventricular Geometry and Function - Results of the longitudinal population based MONICA/KORA-Survey

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Jan Stritzke ◽  
Marcello R Markus ◽  
Wolfgang Lieb ◽  
Andreas Luchner ◽  
Angela Döring ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Weight Gain ◽  
Ventricular Remodeling ◽  
Left Ventricular Remodeling ◽  
Left Ventricular ◽  
Left Ventricular Geometry ◽  
Ventricular Geometry ◽  
And Function

Background: Obesity is related to left ventricular (LV) hypertrophy and diastolic dysfunction. However it remains unclear if changes in life style resulting in loss of body weight also have beneficial effects on left ventricular remodeling. In this study we evaluated the effects of weight loss on left ventricular geometry and function during ten years of follow-up. Methods: Subjects (n=1005, aged 25 to 74 years) who originated from a gender and age stratified random sample of German residents of the Augsburg area were examined by standardized echocardiography at baseline and again after ten years. The associations between weight loss and long-term changes of left ventricular end-diastolic diameter (LVEDD), wall thickness (WT), left ventricular mass (LVM), and left atrial diameter (LA) were assessed. Mean relative changes and odds ratios were computed by statistical models adjusting for gender, age, body height, systolic blood pressure and body weight at baseline. Results: After ten years of follow-up 305 individuals presented with a loss of body weight (−3.5+/−3.4kg on average). Whereas 700 subjects presented with an increase of body weight (+5.4+/−4.7kg). Ageing related changes in LV geometry were significantly different in the two groups. Specifically, individuals with weight loss displayed a favorable geometry with relative changes of WT (+5.9% [CI-95% 4.3, 7.5] vs. + 8.1% [7.0, 9.2], p=0.024), LVEDD (−0.6% [−1.5, 0.2] vs. 30.8% [0.2, 1.4], p=0.008), LVM (+6.5% [4.3, 8.8] vs. +11.9% [10.4, 13.5], p<0.001) and LA (−0.9% [−2.1, 0.2] vs. +2.5% [1.7, 3.3], p<0.001), as compared to individuals with weight gain. Moreover, the risk for incident left ventricular hypertrophy (OR 2.5 [1.5– 4.3], p=0.001) and incident diastolic dysfunction (OR 1.9 [1.1–3.4], p=0.023) was significantly higher in individuals presenting with an increase in body weight. Conclusions: As compared to weight gain, weight loss is associated with a significant deceleration of left ventricular remodeling during ageing of the heart. Nevertheless, even in the weight loss group there was no regression in left ventricular mass detectable. Consequently, early interventions especially in young obese individuals are essential for prevention of premature onset of cardiac remodeling.

scholarly journals Skeletal muscle fiber size and fiber type distribution in human cancer: Effects of weight loss and relationship to physical function

2016 ◽  
Vol 35 (6) ◽  
pp. 1359-1365 ◽  
Author(s):  
Michael J. Toth ◽  
Damien M. Callahan ◽  
Mark S. Miller ◽  
Timothy W. Tourville ◽  
Sarah B. Hackett ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Weight Loss ◽  
Physical Function ◽  
Muscle Fiber ◽  
Human Cancer ◽  
Fiber Type ◽  
Skeletal Muscle Fiber ◽  
Type Distribution ◽  
Fiber Size ◽  
Fiber Type Distribution

scholarly journals Vestigial-like 2 contributes to normal muscle fiber type distribution in mice

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Masahiko Honda ◽  
Kyoko Hidaka ◽  
So-ichiro Fukada ◽  
Ryo Sugawa ◽  
Manabu Shirai ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Normal Muscle ◽  
Type Distribution ◽  
Fiber Type Distribution

scholarly journals Prolonged C2 spinal hemisection-induced inactivity reduces diaphragm muscle specific force with modest, selective atrophy of type IIx and/or IIb fibers

2013 ◽  
Vol 114 (3) ◽  
pp. 380-386 ◽  
Author(s):  
Carlos B. Mantilla ◽  
Sarah M. Greising ◽  
Wen-Zhi Zhan ◽  
Yasin B. Seven ◽  
Gary C. Sieck
Keyword(s):  
Spinal Cord ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Diaphragm Muscle ◽  
Emg Activity ◽  
Type I ◽  
Specific Force ◽  
Type Distribution ◽  
Fiber Size ◽  
Fiber Type Distribution

The diaphragm muscle (DIAm) is critically responsible for sustaining ventilation. Previously we showed in a commonly used model of spinal cord injury, unilateral spinal cord hemisection at C2 (SH), that there are minimal changes to muscle fiber cross-sectional area (CSA) and fiber type distribution following 14 days of SH-induced ipsilateral DIAm inactivity. In the present study, effects of long-term SH-induced inactivity on DIAm fiber size and force were examined. We hypothesized that prolonged inactivity would not result in substantial DIAm atrophy or force loss. Adult rats were randomized to control or SH groups ( n = 34 total). Chronic bilateral DIAm electromyographic (EMG) activity was monitored during resting breathing. Minimal levels of spontaneous recovery of ipsilateral DIAm EMG activity were evident in 42% of SH rats (<25% of preinjury root mean square amplitude). Following 42 days of SH, DIAm specific force was reduced 39%. There was no difference in CSA for type I or IIa DIAm fibers in SH rats compared with age, weight-matched controls (classification based on myosin heavy chain isoform expression). Type IIx and/or IIb DIAm fibers displayed a modest 20% reduction in CSA ( P < 0.05). Overall, there were no differences in the distribution of fiber types or the contribution of each fiber type to the total DIAm CSA. These data indicate that reduced specific force following prolonged inactivity of the DIAm is associated with modest, fiber type selective adaptations in muscle fiber size and fiber type distribution.

Genetic effects in human skeletal muscle fiber type distribution and enzyme activities

1986 ◽  
Vol 64 (9) ◽  
pp. 1245-1251 ◽  
Author(s):  
C. Bouchard ◽  
J. A. Simoneau ◽  
G. Lortie ◽  
M. R. Boulay ◽  
M. Marcotte ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Enzyme Activities ◽  
Fiber Type ◽  
Genetic Effect ◽  
Genetic Effects ◽  
Type I ◽  
Type Distribution ◽  
Fiber Type Distribution ◽  
Mz Twins

The purpose of the study was to estimate the genetic effect for skeletal muscle characteristics using pairs of nontwin brothers (n = 32), dizygotic (DZ) twins (n = 26), and monozygotic (MZ) twins (n = 35). They were submitted to a needle biopsy of the vastus lateralis for the determination of fiber type distribution (I, IIa, IIb) and the following enzymes were assayed for maximal activity: creatine kinase, hexokinase, phosphofructokinase (PFK), lactate dehydrogenase, malate dehydrogenase, 3-hydroxyacyl CoA dehydrogenase, and oxoglutarate dehydrogenase (OGDH). For the percentage of type I fibers, intraclass correlations were 0.33 (p < 0.05), 0.52 (p < 0.01), and 0.55 (p < 0.01) in brothers and DZ and MZ twins, respectively. MZ twins exhibited significant within-pair resemblance for all enzyme activities (0.30 ≤ r ≤ 0.68). In spite of these correlations, genetic analyses performed with the twin data alone indicated that there was no significant genetic effect for muscle fiber type I, IIa, and IIb distribution and fiber areas. Although there were significant correlations in MZ twins for all muscle enzyme activities, the often nonsignificant intraclass coefficients found in brothers and DZ twins suggest that variations in enzyme activities are highly related to common environmental conditions and nongenetic factors. However, genetic factors appear to be involved in the variation of regulatory enzymes of the glycolytic (PFK) and citric acid cycle (OGDH) pathways and in the variation of the oxidative to glycolytic activity ratio (PFK/OGDH ratio). Data show that these genetic effects reach only about 25–50% of the total phenotypic variation when data are adjusted for age and sex differences.

Muscle Fiber Type Distribution in the Normal Human Levator Veli Palatini Muscle

1998 ◽  
Vol 35 (5) ◽  
pp. 419-424 ◽  
Author(s):  
Jerald B. Moon ◽  
Sue Ann Thompson ◽  
Elise Jaeckel ◽  
John W. Canady
Keyword(s):  
Muscle Tissue ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Type I ◽  
Type Ii ◽  
Type Distribution ◽  
Levator Veli Palatini ◽  
Fiber Type Distribution ◽  
Type I Fibers ◽  
Type Ii Fibers

Objective This study examined the muscle fiber type distribution within the normal adult levator veli palatini muscle. Methods Levator veli palatini muscle tissue was harvested from the palates of 12 (seven female, five male) adult noncleft cadavers. Adjacent sections were stained for adenosine triphosphatase at pH 10.4 or 4.2. After mounting, magnifying, and photographing, Type I versus Type II fiber types were differentiated by the intensity of, or by the inhibition of, staining of matched fibers at each pH level. Type I fibers stained light at pH 10.4 and dark at pH 4.2, while Type II fibers stained light at pH 4.2 and dark at pH 10.4. Main outcome Measures The number of fibers counted for each specimen ranged from 60 to 616. The numbers of Type I and Type II stained fibers appearing in each muscle tissue sample were determined and expressed as a percentage of the total number of fibers identified. A few identified fibers could not be labelled as either Type I or Type II. Results The overall proportion of Type I fibers, averaged across all specimens, was 59.8%. Male specimens had 67.4% Type I fibers and 31.8% Type II fibers, while female specimens had 54.4% Type I fibers and 44.4% Type II fibers. Conclusions Observed fiber type distributions were similar to those reported for other articulatory muscles, but differed slightly from previously reported distributions for normal levator veli palatini. The distributions observed in this study provide a baseline against which to relate fiber type data from the levator veli palatini of cleft palates to the functional status of the velopharyngeal mechanism.

Anaerobic Capacity and Muscle Fiber Type Distribution in Man

1980 ◽  
Vol 01 (02) ◽  
pp. 82-85 ◽  
Author(s):  
O. Bar-Or ◽  
R. Dotan ◽  
O. Inbar ◽  
A. Rothstein ◽  
J. Karlsson* ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Fiber Type ◽  
Anaerobic Capacity ◽  
Muscle Fiber Type ◽  
Type Distribution ◽  
Fiber Type Distribution

scholarly journals ACTN3 (R577X) genotype is associated with fiber type distribution

2007 ◽  
Vol 32 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Barbara Vincent ◽  
Katrien De Bock ◽  
Monique Ramaekers ◽  
Els Van den Eede ◽  
Marc Van Leemputte ◽  
...  
Keyword(s):  
Muscle Fiber ◽  
Muscle Power ◽  
Control Function ◽  
Stop Codon ◽  
Fiber Type ◽  
Premature Stop Codon ◽  
Muscle Fiber Type ◽  
Vastus Lateralis Muscle ◽  
Type Distribution ◽  
Fiber Type Distribution

α-Actinin-3 is a Z-disc structural protein found only in type II muscle fibers. The X allele of the R577X polymorphism in the ACTN3 gene results in a premature stop codon and α-actinin-3 deficiency in XX homozygotes. Associations between the R577X polymorphism and the muscle-power performance of elite athletes have been described earlier. About 45% of the fiber type proportions are determined by genetic factors. The ACTN3 variant could be one of the contributing genes in the heritability of fiber type distribution through its interaction with calcineurin. The aim of this study was to quantify the association between the polymorphism and muscle fiber type distribution and fast-velocity knee extension strength. Ninety healthy young men (18–29 y) were genotyped for ACTN3 R577X. Knee extensor strength was measured isometrically (45°) and at different dynamic velocities (100–300°/s) on a programmable dynamometer. Twenty-two XX and twenty-two RR subjects underwent a biopsy of the right vastus lateralis muscle. Fiber type composition was determined by immunohistochemistry. Homozygotes for the R allele show significantly higher relative dynamic quadriceps torques at 300°/s, compared with XX carriers ( P < 0.05). Fiber type characteristics differed significantly between the two genotype groups. The percentage surface and number of type IIx fibers were greater in the RR than the XX genotype group ( P < 0.05), and α-actinin-3 protein content is systematically higher in type IIx compared with type IIa fibers (staining intensity ratio IIx to IIa = 1.17). This study shows that the mechanism, by which the ACTN3 polymorphism has its effect on muscle power, might rely on a control function of fiber type proportions.

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