Role of central circulatory factors in the fat-free mass-maximal aerobic capacity relation across age

1998 ◽  
Vol 275 (4) ◽  
pp. H1178-H1182 ◽  
Author(s):  
Brian E. Hunt ◽  
Kevin P. Davy ◽  
Pamela P. Jones ◽  
Christopher A. DeSouza ◽  
Rachael E. Van Pelt ◽  
...  

Fat-free mass (FFM) (primarily skeletal muscle mass) is related to maximal aerobic capacity among healthy humans across the adult age range. The basis for this physiological association is assumed to be a direct relation between skeletal muscle mass and its capacity to consume oxygen. We tested the alternative hypothesis that FFM exerts its influence on maximal aerobic capacity in part via an association with central circulatory function. To do so, we analyzed data from 103 healthy sedentary adults aged 18–75 yr. FFM was strongly and positively related to maximal oxygen consumption ( r = 0.80, P < 0.001). FFM was also strongly and positively related to supine resting levels of blood volume ( r = 0.79, P < 0.001) and stroke volume ( r = 0.75, P < 0.001). Statistically controlling for the collective influences of blood volume and stroke volume abolished the tight relation between FFM and maximal oxygen consumption ( r = 0.12, not significant). These results indicate that 1) FFM may be an important physiological determinant of blood volume and stroke volume among healthy sedentary adult humans of varying age; and 2) this relation between FFM and central circulatory function appears to represent the primary physiological basis for the strong association between FFM and maximal aerobic capacity in this population. Our findings suggest that sarcopenia (loss of skeletal muscle mass with aging) may contribute to the age-related decline in maximal aerobic capacity primarily via reductions in blood volume and stroke volume rather than a direct effect on the oxygen-consuming potential of muscle per se.

Author(s):  
Catarina N. Matias ◽  
Francesco Campa ◽  
Catarina L. Nunes ◽  
Rubén Francisco ◽  
Filipe Jesus ◽  
...  

Background: An increasing body of evidence indicates that the phase angle (PhA) can be applied as a marker of nutritional status, disease prognosis, and mortality probability. Still, it is not known whether PhA can be used as an indicator of muscular quantity and strength and maximal aerobic capacity in overweight/obese former highly active individuals, an understudied population. This study aimed to analyze the association between PhA with skeletal muscle mass, maximal isometric strength, and maximal aerobic capacity through VO2max, in overweight/obese and inactive former athletes. Methods: Cross-sectional information of 94 (62 males) former adult athletes (age: 43.1 ± 9.4 years old; body mass index: 31.4 ± 4.8 kg/m2) taking part in a weight-loss clinical trial was analyzed. Total fat and fat-free mass were determined by dual-energy X-ray absorptiometry, while skeletal muscle mass was predicted from appendicular lean soft tissue. Values for upper- and lower-body maximal isometric strength were assessed by handgrip and leg press dynamometry. VO2max was determined by indirect calorimetry through a graded exercise test performed on a treadmill. Results: PhA was associated with skeletal muscle mass (r = 0.564, p < 0.001), upper-body strength (r = 0.556, p < 0.001), lower-body strength (r = 0.422, p < 0.001), and VO2max (r = 0.328, p = 0.013). These relationships remained significant for skeletal muscle mass (β = 2.158, p = 0.001), maximal isometric strength (upper-body: β = 2.846, p = 0.012; low-er-body: β = 24.209, p = 0.041) after adjusting for age, sex, and fat mass but not for VO2max (β = −0.163, p = 0.098). Conclusion: Our findings indicated that former athletes with higher values of PhA exhibited greater muscle mass and strength, despite sex, age, and body composition, which suggests that this simple raw BI parameter can be utilized as an indicator of muscle quantity and functionality in overweight/obese former athletes.


2016 ◽  
Vol 41 (6) ◽  
pp. 611-617 ◽  
Author(s):  
Jameason D. Cameron ◽  
Ronald J. Sigal ◽  
Glen P. Kenny ◽  
Angela S. Alberga ◽  
Denis Prud’homme ◽  
...  

There has been renewed interest in examining the relationship between specific components of energy expenditure and the overall influence on energy intake (EI). The purpose of this cross-sectional analysis was to determine the strongest metabolic and anthropometric predictors of EI. It was hypothesized that resting metabolic rate (RMR) and skeletal muscle mass would be the strongest predictors of EI in a sample of overweight and obese adolescents. 304 post-pubertal adolescents (91 boys, 213 girls) aged 16.1 (±1.4) years with body mass index at or above the 95th percentile for age and sex OR at or above the 85th percentile plus an additional diabetes risk factor were measured for body weight, RMR (kcal/day) by indirect calorimetry, body composition by magnetic resonance imaging (fat free mass (FFM), skeletal muscle mass, fat mass (FM), and percentage body fat), and EI (kcal/day) using 3 day food records. Body weight, RMR, FFM, skeletal muscle mass, and FM were all significantly correlated with EI (p < 0.005). After adjusting the model for age, sex, height, and physical activity, only FFM (β = 21.9, p = 0.007) and skeletal muscle mass (β = 25.8, p = 0.02) remained as significant predictors of EI. FFM and skeletal muscle mass also predicted dietary protein and fat intake (p < 0.05), but not carbohydrate intake. In conclusion, with skeletal muscle mass being the best predictor of EI, our results support the hypothesis that the magnitude of the body’s lean tissue is related to absolute levels of EI in a sample of inactive adolescents with obesity.


1997 ◽  
Vol 82 (5) ◽  
pp. 1411-1415 ◽  
Author(s):  
David N. Proctor ◽  
Michael J. Joyner

Proctor, David N., and Michael J. Joyner. Skeletal muscle mass and the reduction ofV˙o 2 max in trained older subjects. J. Appl. Physiol.82(5): 1411–1415, 1997.—The role of skeletal muscle mass in the age-associated decline in maximal O2 uptake (V˙o 2 max) is poorly defined because of confounding changes in muscle oxidative capacity and in body fat and the difficulty of quantifying active muscle mass during exercise. We attempted to clarify these issues by examining the relationship between several indexes of muscle mass, as estimated by using dual-energy X-ray absorptiometry and treadmillV˙o 2 max in 32 chronically endurance-trained subjects from four groups ( n = 8/group): young men (20–30 yr), older men (56–72 yr), young women (19–31 yr), and older women (51–72 yr).V˙o 2 max per kilogram body mass was 26 and 22% lower in the older men (45.9 vs. 62.0 ml ⋅ kg−1 ⋅ min−1) and older women (40.0 vs. 51.5 ml ⋅ kg−1 ⋅ min−1). These age differences were reduced to 14 and 13%, respectively, whenV˙o 2 max was expressed per kilogram of appendicular muscle. When appropriately adjusted for age and gender differences in appendicular muscle mass by analysis of covariance, whole bodyV˙o 2 max was 0.50 ± 0.09 l/min less ( P < 0.001) in the older subjects. This effect was similar in both genders. These findings suggest that the reducedV˙o 2 max seen in highly trained older men and women relative to their younger counterparts is due, in part, to a reduced aerobic capacity per kilogram of active muscle independent of age-associated changes in body composition, i.e., replacement of muscle tissue by fat. Because skeletal muscle adaptations to endurance training can be well maintained in older subjects, the reduced aerobic capacity per kilogram of muscle likely results from age-associated reductions in maximal O2 delivery (cardiac output and/or muscle blood flow).


2007 ◽  
Vol 102 (6) ◽  
pp. 2142-2148 ◽  
Author(s):  
Sean Walsh ◽  
E. Jeffrey Metter ◽  
Luigi Ferrucci ◽  
Stephen M. Roth

Genetic variation in myostatin, a negative regulator of skeletal muscle, in cattle has shown remarkable influence on skeletal muscle, resulting in a double-muscled phenotype in certain breeds; however, DNA sequence variation within this gene in humans has not been consistently associated with skeletal muscle mass or strength. Follistatin and activin-type II receptor B ( ACVR2B) are two myostatin-related genes involved in the regulation and signaling of myostatin. We sought to identify associations between genetic variation and haplotype structure in both follistatin and ACVR2B with skeletal muscle-related phenotypes. Three hundred fifteen men and 278 women aged 19–90 yr from the Baltimore Longitudinal Study of Aging were genotyped to determine respective haplotype groupings (Hap Groups) based on HapMap data. Whole body soft tissue composition was measured by dual-energy X-ray absorptiometry. Quadriceps peak torque (strength) was measured using an isokinetic dynamometer. Women carriers of ACVR2B Hap Group 1 exhibited significantly less quadriceps muscle strength (shortening phase) than women homozygous for Hap Group 2 (109.2 ± 1.9 vs. 118.6 ± 4.1 N·m, 30°/s, respectively, P = 0.036). No significant association was observed in men. Male carriers of follistatin Hap Group 3 exhibited significantly less total leg fat-free mass than noncarriers (16.6 ± 0.3 vs. 17.5 ± 0.2 kg, respectively, P = 0.012). No significant associations between these haplotype groups were observed in women. These results indicate that haplotype structure at the ACVR2B and follistatin loci may contribute to interindividual variation in skeletal muscle mass and strength, although these data indicate sex-specific relationships.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e15566-e15566
Author(s):  
Samantha Cushen ◽  
Aoife M Ryan ◽  
MinYuen Teo ◽  
Peter MacEneaney ◽  
Patrick McLaughlin ◽  
...  

e15566 Background: Sunitinib is a standard first-line option for metastatic renal cell cancer (mRCC). Identification of biomarkers associated with outcome or toxicity is a challenge. Body composition is a prognostic factor in cancer and sarcopenia is associated with treatment toxicity and survival. We investigated if body composition by CT scan predicted dose limiting toxicity (DLT) from sunitinib in mRCC. Methods: Patients (pts) with mRCC receiving sunitinib 50mg as 1stline therapy between 2007-2012 were included. Ethical approval was obtained and prospectively maintained databases analysed. Skeletal muscle cross-sectional area at L3 was measured by CT. Sarcopenia was defined using published cut offs. Toxicity was assessed after 4 cycles of drug (CTCAE, v4.0). Results: 55 pts (43 male), mean age 64yrs (±10.6) were included. 67% were overweight/obese (BMI>25kg/m2). Sarcopenia was present in 33% (56% of normal BMI, 44% overweight group). Overall 40 pts (73%) experienced DLT (51% M, 100% F, p<0.016). DLT occurred in <6 months in 53% (44% M vs 83% F, p<0.016) and these pts were older (mean 68 yrs vs 60 yrs, p<0.01), had lower skeletal muscle mass (51.8 cm2/m2 vs 59.4 cm2/m2, p<0.012), and fat free mass (FFM) (51.4kg vs 57.7kg, p<0.03), and received higher drug dose in mg/kg FFM (1.01 vs 0.89, p<0.02). Common toxicities were GI (65%) and fatigue (47%). Of pts <25th percentile skeletal muscle mass 92% experienced DLT, higher than pts >75th percentile (p<0.05). Pts <25th percentile had an average of 5 toxicities vs 2 in those >75th percentile (p<0.003). All toxicities were more common in muscle wasted patients (p<0.05). 77% (n=10) of pts receiving a drug dose >75th percentile (1.105mg/FFM) experienced DLT in <6 months vs 44% (n=17) receiving a dose <75thpercentile (<1.099mg/FFM; p<0.037). Conclusions: Sarcopenia is prevalent in patients with mRCC, is easily measured, is an occult condition in pts with normal/high BMI, and is a significant predictor of DLT in pts receiving 1st line sunitinib. Our results highlight the potential use of baseline body composition to predict toxicity. The role of sarcopenia in targeted therapy is evolving and its potential to predict toxicity should be further studied.


2021 ◽  
Vol 5 (2) ◽  
pp. 127
Author(s):  
Aprilia Kusumawardhani ◽  
Farapti Farapti ◽  
Mahmud Aditya Rifqi ◽  
Sri Adiningsih

ABSTRAK Latar Belakang :Gizi olahraga merupakan aspek penting dalam mengatur asupan makanan dan komposisi tubuh untuk mencapai performa yang optimal. Studi epidemiologis menunjukkan sebagian besar asupan atlet tidak adekuat dan dapat mempengaruhi komposisi tubuh yang ideal.Tujuan :Tujuan dari penelitian ini adalah untuk menganalisis pengaruh pendampingan gizi olahraga terhadap komposisi tubuh dan asupan energi atlet bela diri.Metode :Pendampingan gizi intensif dilakukan selama empat bulan (Juni- September 2019). Pengukuran komposisi tubuh  dilakukan 2 kali, yakni sebelum dan sesudah intervensi dengan menganalisis hasil pengukuran dari alat BIA (Bio Impadance Analyzer) tipe MBCA (Medical Body Compotiton Analyzer) 515/514 merk seca©. Variabel yang dianalisis diantaranya, total asupan kalori sehari diukur menggunakan instrumen Recall-24 jam, komposisi tubuh diukur dengan alat BIA yakni Fat Mass (FM), Fat Free Mass (FFM) dan Skeletal Muscle Mass (SMM). Pendampingan gizi dilakukan oleh ahli gizi olahraga yang mengunjungi 24 responden setiap bulan dan memberikan materi pendidikan gizi, memberikan makanan sehat dan memberikan konseling permasalahan gizi atlet.Hasil : Hasil penelitian ini menunjukkan adanya peningkatan secara signifikan pada asupan energi total (1496,2±654,4 menjadi 1688,5±679,8, p= 0,002). Pada komposisi tubuh terjadi peningkatan pada FFM dan SMM yakni (56,57 ± 9,91 kg vs 57,01 ± 9,53, p = 0,032) dan (27,49 ± 5,58 vs 27,75 ± 5,31, p = 0,005) dan tidak ada perbedaan signifikan dalam variabel  FM.Kesimpulan : Kesimpulan dari percobaan ini adalah pendampingan gizi secara intensif dapat meningkatkan asupan energi total, FFM dan SMM pada atlet bela diri. Kata Kunci : Komposisi tubuh, pendampingan gizi, asupan energiABSTRACTBackground :Sports nutrition is very urgent to improve nutrition knowledge, dietary intake and body composition to achieve an optimum athletic performance. Epidemiological studies showed most athletes lack of getting adequate intake and maintaining an ideal body composition.Objective :This study aims to analyze the effect of sport nutrition education on body composition and energy intake among elite combat sport athletes.Methods :Intensive sport nutrition was conducted for four months June until September 2019. Body composition was assessed  for 2 times, before and after intervention using bioelectric impedance analysis (BIA), with seca© brand 515/514 type of stainless steel electrodes.Measurement of energy intake with recall 24 hours before and after the intervention. The variables studied were Fat Mass (FM), Fat Free Mass (FFM), Skeletal Muscle Mass (SMM) and energy intake.The professional sport nutritionist and dietitians visited 24 subjects every month by teaching nutrition education, bringing the healthy food, and facilitating the counseling about sport nutrition.Result :Energy intake increased significantly (1496,2±654,4 to 1688,5±679,8, p= 0,002). FFM and SMM increased significantly pre to post (56.57±9.91 kg vs 57.01±9.53, p=0.032) and (27.49±5.58 vs 27.75±5.31, p=0.005) respectively, meanwhile no significant differences in FM variable.Conclusion : Our findings indicate that intensive sport nutritionimproved energy intake, FFM and SMM among elite combat sport athletes. Keywords : Body compotition, sport nutririon education, energy intake


2021 ◽  
Author(s):  
Aliyu Tijani Jibril ◽  
Atieh Mirzababaei ◽  
Farideh Shiraseb ◽  
Niloufar Rasaei ◽  
Khadijeh Mirzaei

Abstract Objectives Obesity is a major risk factor for metabolic syndrome, with its prevalence has increased over the past decade. Major changes in body composition with aging have a significant effect on many clinical outcomes. Sarcopenic obesity consists of both the presence of abnormal adipose tissue with a deficit of muscle mass. Results Of the 241 subjects in this study (average age 35.32 years), 176 (73.03%) were classified as MUO phenotype. Based on this study, the prevalence of sarcopenic obesity was 7.88%. We found that high fat-free mass was more strongly and significantly associated with MUO phenotype. Furthermore, we found that individuals with high fat-free mass and high skeletal muscle mass had a significantly low prevalence of MUO phenotype. A significant positive correlation between metabolic phenotypes and sarcopenic obesity was also observed after all potential covariates were adjusted for. These results of this study suggest that increased adiposity and decreased skeletal muscle mass are associated with unfavorable metabolic traits among overweight and obese Iranian women. SO was also found to be associated with a greater risk of developing MUO phenotype.


Author(s):  
Ngan Thi Kim Nguyen ◽  
Nguyen-Phong Vo ◽  
Shih-Yi Huang ◽  
Weu Wang

Besides massive body weight loss, laparoscopic sleeve gastrectomy (LSG) causes massive lean mass, including fat-free mass (FFM) and skeletal muscle mass (SM) that present higher metabolic rates in males. This study examines sex differences in FFM and SM changes of type 2 diabetes (T2D) remission at 12 months post-LSG. This cohort study recruited 119 patients (53.7% females) with T2D and obesity (body mass index 42.2 ± 7.0 kg/m2) who underwent LSG. Fat-mass (FM) loss was higher in males than in females (−12.8 ± 6.2% vs. −9.9 ± 5.0%, p = 0.02) after one-year post-operation. Regardless of the weight-loss difference, males had higher FFM and SM gain than did females (12.8 ± 8.0 vs. 9.9 ± 5.0% p = 0.02 and 6.5 ± 4.3% vs. 4.9 ± 6.2%, p = 0.03, respectively). Positive correlations of triglyceride reduction with FM loss (r = 0.47, p = 0.01) and SM gain (r = 0.44, p = 0.02) over 12 months post-operation were observed in males who achieved T2D remission. The T2D remission rate significantly increased 16% and 26% for each additional percentage of FFM and SM gain one year after LSG, which only happened in males. Increased FFM and SM were remarkably associated with T2D remission in males, but evidence lacks for females.


2019 ◽  
Vol 39 (7) ◽  
Author(s):  
Laura Regué ◽  
Fei Ji ◽  
Daniel Flicker ◽  
Dana Kramer ◽  
William Pierce ◽  
...  

ABSTRACT Insulin-like growth factor 2 (IGF2) mRNA binding protein 2 (IMP2) was selectively deleted from adult mouse muscle; two phenotypes were observed: decreased accrual of skeletal muscle mass after weaning and reduced wheel-running activity but normal forced treadmill performance. Reduced wheel running occurs when mice are fed a high-fat diet but is normalized when mice consume standard chow. The two phenotypes are due to altered output from different IMP2 client mRNAs. The reduced fiber size of IMP2-deficient muscle is attributable, in part, to diminished autocrine Igf2 production; basal tyrosine phosphorylation of the insulin and IGF1 receptors is diminished, and Akt1 activation is selectively reduced. Gsk3α is disinhibited, and S536-phosphorylated ε subunit of eukaryotic initiation factor 2B [eIF2Bε(S536)] is hyperphosphorylated. Protein synthesis is reduced despite unaltered mTOR complex 1 activity. The diet-dependent reduction in voluntary exercise is likely due to altered muscle metabolism, as contractile function is normal. IMP2-deficient muscle exhibits reduced fatty acid oxidation, due to a reduced abundance of mRNA of peroxisome proliferator-activated receptor α (PPARα), an IMP2 client, and PPARα protein. IMP2-deficient muscle fibers treated with a mitochondrial uncoupler to increase electron flux, as occurs with exercise, exhibit reduced oxygen consumption from fatty acids, with higher oxygen consumption from glucose. The greater dependence on muscle glucose metabolism during increased oxygen demand may promote central fatigue and thereby diminish voluntary activity.


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