Matching Items (3)

Mechanisms of Sarcopenia

Description

Sarcopenia, a disease defined by age-related muscle loss and function, impacts each and every one of us as we age. Medical research over the past 40 years has identified dozens

Sarcopenia, a disease defined by age-related muscle loss and function, impacts each and every one of us as we age. Medical research over the past 40 years has identified dozens of factors that contribute to Sarcopenia, including, hormonal changes, deficiencies in nutrition, denervation, changes in physical activity and diseases. Developing effective therapeutic treatments for Sarcopenia is dependent on identifying the mechanisms by which these factors affect muscle loss and understanding the interrelationship of these mechanisms. I conducted my research by compiling and analyzing several previous studies on many different mechanisms that contribute to Sarcopenia. Of these mechanisms, I determined the most significant mechanisms and mapped them out on a visual presentation. In addition to the contributing factors listed above, I found that dysregulated cell signaling, mitochondrial abnormalities, impaired autophagy/protein regulation, altered nitric oxide production, and systemic inflammation all contribute to Sarcopenia. Their impact on skeletal muscle is manifested by reduced satellite function, reduced regenerative capacity, loss of muscle mass, accumulation of damaged products, and fibrosis. My research clearly demonstrated that there was not a one-to-one correlation between factors and specific pathological characteristics of Sarcopenia. Instead, factors funneled into a discrete number of cellular processes, including cell proliferation, protein synthesis, and autophagy and apoptosis. Based on my findings, the overall cause of Sarcopenia appears to be a loss of balance between these pathways. The results of my thesis indicate that Sarcopenia is a multifactorial disorder, and therefore, effective therapy should consist of those that prevent necrosis associated with autophagy and apoptosis.

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Date Created
  • 2017-05

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Feasibility of Using a Non-Counter Movement Squat to Assess Lower Body Strength in Adults Ages 20-70 years.

Description

The purpose of this study was to investigate the Feasibility of Using a Non-Counter Movement Squat to Assess Lower Body Strength in Adults ages 20-70 years. Feasibility was tested by

The purpose of this study was to investigate the Feasibility of Using a Non-Counter Movement Squat to Assess Lower Body Strength in Adults ages 20-70 years. Feasibility was tested by measuring five feasibility metrics described by Bowen et al. (Bowen et al., 2009): Acceptability, Demand, Implementation, Practicality, and Limited Efficacy. Seven male subjects and fifteen female subjects participated in the study. The subjects had their height, weight, body fat percentage by bioelectrical impedance analysis (BIA), and grip strength measured. Subjects performed a warm-up on a cycle ergometer, a Non-Counter Movement Squat Test (NCMST) 1-repetition maximal strength test using a Smith machine, and a cool down on a treadmill. Each subject then completed a post-participation questionnaire used to measure acceptability, Demand was measured by subjects who agreed to participate, implementation was measured by subjects who completed the protocol, practicality was measured by an administrator survey, and limited efficacy was measured by distribution of strength results by age and for all subjects by sex. Results showed acceptance of hypotheses of acceptability, demand, implementation and practicality for both males and females. Limited efficacy was inconclusive for both males and females resulting in rejection of hypothesis. The findings of this study show that further research is needed to compare the NCMST to other lower body muscular strength tests to determine the validity of the NCMST.

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Created

Date Created
  • 2019

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Muscle quality, muscle mass, muscle strength, and pulse wave velocity between healthy young and elderly adults

Description

Although maintaining an optimal level of muscle quality in older persons is necessary to prevent falls and disability, there has been limited research on muscle quality across age and gender

Although maintaining an optimal level of muscle quality in older persons is necessary to prevent falls and disability, there has been limited research on muscle quality across age and gender groups. The associations of muscle quality, muscle strength, and muscle mass also remain less explored. Purpose: This study examined the muscle quality differences (arm and leg) between healthy young and elderly adults across gender groups. This study also examined the associations of muscle quality, muscle strength, and muscle mass in young and elderly adults, respectively. Methods: Seventy-one total subjects were recruited for this study within age groups 20-29 years old (20 females and 20 males) and 60-80 years old (18 females and 13 males). All participants completed anthropometric measures, dual-energy x-ray absorptiometry, pulse wave velocity, handgrip strength and leg strength tests, gait speed, and sit to stand test. Results: Young male adults had a greater leg muscle quality index (leg MQI) than did elderly male adults (21.8 Nm/kg vs. 16.3 Nm/kg, p = 0.001). Similarly, young female adults had a greater leg MQI than did old female adults (21.3 Nm/kg and 15.6 Nm/kg, p<0.001). For arm muscle quality index (arm MQI), there was a gender difference in young adults (p = 0.001), but not for the elderly adults. Among elderly adults, there was a positive association between leg MQI and isometric leg strength (r = 0.79, p<0.001). Notably, there was a negative association between leg MQI and leg lean mass (r = -0.70, p<0.001) and between arm MQI and arm lean mass (r = -0.58, p = 0.001). In young adults, there was also a positive association between arm MQI and handgrip strength (r = 0.53, p<0.001) and between leg MQI and isometric leg strength (r = 0.81, p<0.001). There was no association between muscle quality and muscle mass in young adults. Conclusion: Young adults had a greater leg muscle quality than did elderly adults in both men and women. Leg muscle quality is positively associated with leg muscle strength in both young and elderly adults but is inversely associated with leg muscle mass in the elderly adults.

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Created

Date Created
  • 2017