scholarly journals How Does Testosterone Augment the Anabolic Response to Exercise in Frail Older Adults?

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 297-297
Author(s):  
Shalendar Bhasin

Abstract Testosterone treatment increases muscle mass, strength, and leg power in menopausal women, hypogonadal men, older men with mobility limitation, COPD and ESRD. Testosterone's effects on muscle mass and strength are augmented by exercise training and growth hormone. Testosterone treatment improves some measures of physical performance, such as stair climbing power and aerobic capacity; the improvements in gait speed have been modest. Testosterone increases muscle mass by inducing the hypertrophy of type 1 and 2 muscle fibers, and by increasing satellite cell number. Testosterone promotes the differentiation of mesenchymal progenitor cells into myogenic lineage and inhibits their differentiation into adipogenic lineage by activating Wnt-target genes, including follistatin that plays an important role in mediating testosterone's effects on the muscle. Testosterone also increases polyamine synthesis in the muscle. Combined administration of testosterone plus multi-component exercise intervention that includes functional training may be needed to improve function and mobility in older adults.

2019 ◽  
Vol 10 (6) ◽  
pp. 1266-1275 ◽  
Author(s):  
Mikel L. Sáez de Asteasu ◽  
Nicolás Martínez‐Velilla ◽  
Fabricio Zambom‐Ferraresi ◽  
Álvaro Casas‐Herrero ◽  
Eduardo L. Cadore ◽  
...  

2005 ◽  
Author(s):  
Bruce Reeder ◽  
Karen Chad ◽  
Liz Harrison ◽  
Nigel Ashworth ◽  
Suzanne Sheppard ◽  
...  

2021 ◽  
pp. 1-16
Author(s):  
Majid Mufaqam Syed-Abdul ◽  
Chrissa L. McClellan ◽  
Elizabeth J. Parks ◽  
Stephen D. Ball

Abstract Ageing is associated with reduced muscle mass, strength, flexibility and balance, resulting in a poor quality of life (QOL). Past studies have occurred in highly controlled laboratory settings which provide strong support to determine whether similar gains can be made in community programmes. Twenty participants were enrolled in an eight-week community-based resistance training programme (mean age = 61.3 (standard error (SE) = 0.9) years); Body Mass Index = 32.0 (SE = 1.3) kg/m2). All participants completed surveys to assess outcomes associated with QOL. Given the relationship between muscle function and nerve health, nerve conduction studies (NCS) were also conducted in a separate group of participants (mean age = 64.9 (SE = 2.0) years; Body Mass Index = 32.6 (SE = 1.9) kg/m2). This community-based training programme significantly improved QOL measures in older adults (p < 0.001). Although weight loss was not the primary outcome of the study, participants reduced their body weights (p < 0.001), by primarily reducing fat mass (p = 0.007) while maintaining muscle mass. Significant improvements were observed in muscle strength (2.2%), flexibility and balance (3.2–464.2%, p ⩽ 0.05 for all). Improvements were also observed in plasma glucose (p = 0.05), haemoglobin A1C (p = 0.06) and aldolase enzyme levels (p < 0.001). Scores for surveys on memory and sleep improved (p < 0.05). Improved QOL was associated with increased lean mass (r = −0.714, p = 0.002), decreased fat mass (r = −0.702, p = 0.003) and improved flexibility and balance (r = −0.627, p = 0.008). An eight-week, community-based resistance training programme significantly improved QOL in older adults. Influence on the lipid profile and NCS still needs further investigation.


2021 ◽  
Vol 22 (4) ◽  
pp. 792-802.e2
Author(s):  
Berber G. Dorhout ◽  
Annemien Haveman-Nies ◽  
Ellen J.I. van Dongen ◽  
Nick L.W. Wezenbeek ◽  
Esmée L. Doets ◽  
...  

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 814
Author(s):  
Donghao Zhang ◽  
Jinshan Ran ◽  
Jingjing Li ◽  
Chunlin Yu ◽  
Zhifu Cui ◽  
...  

The proliferation and differentiation of skeletal muscle satellite cells (SMSCs) play an important role in the development of skeletal muscle. Our previous sequencing data showed that miR-21-5p is one of the most abundant miRNAs in chicken skeletal muscle. Therefore, in this study, the spatiotemporal expression of miR-21-5p and its effects on skeletal muscle development of chickens were explored using in vitro cultured SMSCs as a model. The results in this study showed that miR-21-5p was highly expressed in the skeletal muscle of chickens. The overexpression of miR-21-5p promoted the proliferation of SMSCs as evidenced by increased cell viability, increased cell number in the proliferative phase, and increased mRNA and protein expression of proliferation markers including PCNA, CDK2, and CCND1. Moreover, it was revealed that miR-21-5p promotes the formation of myotubes by modulating the expression of myogenic markers including MyoG, MyoD, and MyHC, whereas knockdown of miR-21-5p showed the opposite result. Gene prediction and dual fluorescence analysis confirmed that KLF3 was one of the direct target genes of miR-21-5p. We confirmed that, contrary to the function of miR-21-5p, KLF3 plays a negative role in the proliferation and differentiation of SMSCs. Si-KLF3 promotes cell number and proliferation activity, as well as the cell differentiation processes. Our results demonstrated that miR-21-5p promotes the proliferation and differentiation of SMSCs by targeting KLF3. Collectively, the results obtained in this study laid a foundation for exploring the mechanism through which miR-21-5p regulates SMSCs.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 269-269
Author(s):  
Kenneth Madden ◽  
Boris Feldman ◽  
Shane Arishenkoff ◽  
Graydon Meneilly

Abstract The age-associated loss of muscle mass and strength in older adults is called sarcopenia, and it is associated with increased rates of falls, fractures, hospitalizations and death. Sarcopenia is one of the most common physical etiologies for increased frailty in older adults, and some recent work has suggested the use of Point-of care ultrasound (PoCUS) measures as a potential measure of muscle mass. The objective of this study was to examine the association of PoCUS measures of muscle thickness (MT) with measures of frailty in community-dwelling older adults. We recruited 150 older adults (age &gt;= 65; mean age 80.0±0.5 years, 66 women, 84 men) sequentially from 5 geriatric medicine clinics (Vancouver General Hospital). We measured lean muscle mass (LMM, by bioimpedance assay) and an ultrasonic measure of muscle quantity (MT, vastus medialis muscle thickness) in all subjects, as well as two outcome measures of frailty (FFI, Fried Frailty Index; RCFS, Rockwood Clinical Frailty Scale). In our models, MT showed an inverse correlation with the FFI (Standardized β=-0.2320±0.107, p=0.032) but no significant correlation with the RCFS (Standardized β = -0.025±0.086, p=0.776). LMM showed no significant association with either FFI (Standardized β=-0.232±0.120, p=0.055) or RCFS (Standardized β = -0.043±0.119, p=0.719). Our findings indicate that PoCUS measures show potential as a way to screen for physical manifestations of frailty and might be superior to other bedside methods such as bioimpedance assay. However, PoCUS measures of muscle thickness will likely miss patients showing frailty in the much broader context captured by the RCFS.


Author(s):  
Susan Greimel ◽  
Jean F Wyman ◽  
Lin Zhang ◽  
Fang Yu

Abstract Background Recruiting older adults with Alzheimer’s disease (AD) dementia into clinical trials is challenging requiring multiple approaches. We describe recruitment and screening processes and results from the FIT-AD Trial, a single site, pilot randomized controlled trial testing the effects of a 6-month aerobic exercise intervention on cognition and hippocampal volume in community-dwelling older adults with mild-to moderate AD dementia. Methods Ten recruitment strategies and a four-step screening process were used to ensure a homogenous sample and exercise safety. The initial target sample was 90 participants over 48 months which was increased to 96 to allow those in the screening process to enroll if qualified. A tertiary analysis of recruitment and screening rates, recruitment yields and costs, and demographic characteristics of participants was conducted. Results During the 48-month recruiting period, 396 potential participants responded to recruitment efforts, 301 individuals were reached and 103 were tentatively qualified. Of these, 67 (69.8%) participants completed the optional magnetic resonance (MRI) imaging and seven were excluded due to abnormal MRI findings. As a result, we enrolled 96 participants with a 2.92 screen ratio, 2.14 recruitment rate, and 31.9% recruitment yield. Referrals (28.1%) and Alzheimer’s Association events/services (21.9%) yielded over 49% of the enrolled participants. Total recruitment cost was $ 38,246 or $ 398 per randomized participant. Conclusions A multi-prong approach involving extensive community outreach was essential in recruiting older adults with AD dementia into a single-site trial. For every randomized participant, three individuals needed to be screened. Referrals were the most cost-effective recruitment strategy.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Marina Petrella ◽  
Ivan Aprahamian ◽  
Ronei Luciano Mamoni ◽  
Carla Fernanda de Vasconcellos Romanini ◽  
Natália Almeida Lima ◽  
...  

Abstract Background To investigate whether an exercise intervention using the VIVIFRAIL© protocol has benefits for inflammatory and functional parameters in different frailty status. Methods/design This is a randomized clinical trial in an outpatient geriatrics clinic including older adults ≥60 years. For each frailty state (frail, pre-frail and robust), forty-four volunteers will be randomly allocated to the control group (n = 22) and the intervention group (n = 22) for 12 weeks. In the control group, participants will have meetings of health education while those in the intervention group will be part of a multicomponent exercise program (VIVIFRAIL©) performed five times a week (two times supervised and 3 times of home-based exercises). The primary outcome is a change in the inflammatory profile (a reduction in inflammatory interleukins [IL-6, TNF- α, IL1beta, IL-17, IL-22, CXCL-8, and IL-27] or an increase in anti-inflammatory mediators [IL-10, IL1RA, IL-4]). Secondary outcomes are change in physical performance using the Short Physical Performance Battery, handgrip strength, fatigue, gait speed, dual-task gait speed, depressive symptoms, FRAIL-BR and SARC-F scores, and quality of life at the 12-week period of intervention and after 3 months of follow-up. Discussion We expect a reduction in inflammatory interleukins or an increase in anti-inflammatory mediators in those who performed the VIVIFRAIL© protocol. The results of the study will imply in a better knowledge about the effect of a low-cost intervention that could be easily replicated in outpatient care for the prevention and treatment of frailty, especially regarding the inflammatory and anti-inflammatory pathways involved in its pathophysiology. Trial registration Brazilian Registry of Clinical Trials (RBR-9n5jbw; 01/24/2020). Registred January 2020. http://www.ensaiosclinicos.gov.br/rg/RBR-9n5jbw/.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Chewchuk ◽  
Sanzida Jahan ◽  
David Lohnes

AbstractThe intestinal epithelium is a unique tissue, serving both as a barrier against pathogens and to conduct the end digestion and adsorption of nutrients. As regards the former, the intestinal epithelium contains a diverse repertoire of immune cells, including a variety of resident lymphocytes, macrophages and dendritic cells. These cells serve a number of roles including mitigation of infection and to stimulate regeneration in response to damage. The transcription factor Cdx2, and to a lesser extent Cdx1, plays essential roles in intestinal homeostasis, and acts as a context-dependent tumour suppressor in colorectal cancer. Deletion of Cdx2 from the murine intestinal epithelium leads to macrophage infiltration resulting in a chronic inflammatory response. However the mechanisms by which Cdx2 loss evokes this response are poorly understood. To better understand this relationship, we used a conditional mouse model lacking all intestinal Cdx function to identify potential target genes which may contribute to this inflammatory phenotype. One such candidate encodes the histocompatability complex protein H2-T3, which functions to regulate intestinal iCD8α lymphocyte activity. We found that Cdx2 occupies the H3-T3 promoter in vivo and directly regulates its expression via a Cdx response element. Loss of Cdx function leads to a rapid and pronounced attenuation of H2-T3, followed by a decrease in iCD8α cell number, an increase in macrophage infiltration and activation of pro-inflammatory cascades. These findings suggest a previously unrecognized role for Cdx in intestinal homeostasis through H2-T3-dependent regulation of iCD8α cells.


Sports ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 23 ◽  
Author(s):  
Nobuko Hongu ◽  
Mieko Shimada ◽  
Rieko Miyake ◽  
Yusuke Nakajima ◽  
Ichirou Nakajima ◽  
...  

Stair climbing provides a feasible opportunity for increasing physical activity (PA) in daily living. The purpose of this study was to examine the daily walking and stair-climbing steps among healthy older adults (age: 74.0 ± 4.9 years; Body Mass Index (BMI): 22.3 ± 2.5 kg/m2). Participants (34 females and 15 males) attended a weekly 6-month community-based PA program. During the entire program period, daily walking and stair-climbing steps were recorded using a pedometer (Omron, HJA-403C, Kyoto, Japan). Before and after the 6-month program, height, body weight and leg muscle strength were assessed. After the 6-month program, the mean walking and stair-climbing steps in both women and men increased significantly (p ≤ 0.01). Daily stair-climbing steps increased about 36 steps in women and 47 steps in men. At the end of 6 months, only male participants had significant correlation between the number of stair steps and leg muscle strength (r = 0.428, p = 0.037). This study reported that healthy older adults attending the community-based PA program had regular stair-climbing steps during daily living. Promoting stair climbing as an exercise routine was feasible to increase their walking and stair-climbing steps.


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