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Sarcopenia: From Diagnosis to Health Consequences and Nutritional Treatment

A special issue of Nutrients (ISSN 2072-6643). This special issue belongs to the section "Sports Nutrition".

Deadline for manuscript submissions: closed (31 July 2020) | Viewed by 64878

Special Issue Editors


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Guest Editor
Department of Medicine, Section of Geriatrics, Healthy Aging Center, University of Verona, Verona, Italy
Interests: body composition; sarcopenia; malnutrition; ectopic fat deposition
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Translational Research Institute, AdventHealth, Orlando, FL, USA
Interests: skeletal muscle; aging; exercise; mitochondria; obesity

Special Issue Information

Dear Colleagues,

With aging, a progressive decrease in skeletal muscle mass, which leads to a loss of strength and muscle function, is observed, defined by the term sarcopenia. This condition has a prevalence between 10% and 30%, depending on the setting and has recently been associated with ICD-10 code (M62.84). An insufficient protein dietary intake is one of the main causes leading to sarcopenia, and dietary recall by an expert dietician always has to be considered in order to decide which subjects are at risk for this condition.

The loss of muscle mass causes a reduction in strength, aerobic and functional capacity, associated with a high risk of worsening disability, mortality, and other unfavorable outcomes.

The European Working Group on Sarcopenia in Older People (EWGSOP2) recently revised the definition of sarcopenia, establishing three criteria necessary to diagnose sarcopenia: reduced muscle strength; reduction of the quantity or quality of the muscle; and reduction of physical performance.

In recent years, these measurements have become more available in impatient and outpatient clinics in order to screen elderly persons for this condition.

Sarcopenia is mainly observed in the elderly population, but it can also be observed in people over 50 due to particular conditions, such as prolonged bed rest or chronic diseases.

Sarcopenia manifests itself as chronic fatigue, muscle weakness, greater difficulty in lifting loads or performing normal daily activities.

Nutrition, since the middle ages, has played a pivotal role in the prevention of sarcopenia. Aminoacids and protein supplementation has been proposed as a strategy to counteract this phenomenon.

A lot of uncertainties still surround this condition—namely, in terms of (i) pathophysiology, (ii) adverse short- and long-term health effects, and (iii) nutritional management. In fact, no consensus exists on sarcopenia’s effects on health outcomes and optimum nutritional treatment strategies for this condition.

Therefore, we encourage investigators from different scientific backgrounds to submit to this Research Topic entitled “Sarcopenia: From Diagnosis to Health Consequences and Nutritional Treatment” that will accept manuscripts in the form of original research, systematic review, review, mini-review, and clinical trial articles providing a platform for the presentation of recent advances in our knowledge on sarcopenia.

In brief, three important clinical questions (but not limited to) that need to be addressed are:

  • Which are the new insights in sarcopenia pathophysiology?
  • What role is there for nutrition, different dietary patterns, and supplementation?
  • What role is there for exercise and physical activity associated with nutritional intervention?

Prof. Dr. Andrea Rossi
Dr. Giovanna Distefano
Guest Editors

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Keywords

  • Sarcopenia
  • Muscle mass
  • Muscle strength
  • Physical performance
  • Nutrition
  • Aminoacids
  • Supplements
  • Proteins

Published Papers (12 papers)

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Research

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10 pages, 479 KiB  
Article
Sarcopenia Risk Evaluation in a Sample of Hospitalized Elderly Men and Women: Combined Use of the Mini Sarcopenia Risk Assessment (MSRA) and the SARC-F
by Andrea P. Rossi, Cesare Caliari, Silvia Urbani, Francesco Fantin, Piero Brandimarte, Angela Martini, Elena Zoico, Giulia Zoso, Alessio Babbanini, Alfredo Zanotelli and Mauro Zamboni
Nutrients 2021, 13(2), 635; https://0-doi-org.brum.beds.ac.uk/10.3390/nu13020635 - 16 Feb 2021
Cited by 11 | Viewed by 2755
Abstract
Background: SARC-F and Mini Sarcopenia Risk Assessment (MSRA) questionnaires have been proposed as screening tools to identify patients at risk of sarcopenia. The aim of this study is to test the use of SARC-F and MSRA, alone and combined, as a pre-screening tool [...] Read more.
Background: SARC-F and Mini Sarcopenia Risk Assessment (MSRA) questionnaires have been proposed as screening tools to identify patients at risk of sarcopenia. The aim of this study is to test the use of SARC-F and MSRA, alone and combined, as a pre-screening tool for sarcopenia in geriatric inpatients. Methods: 152 subjects, 94 men and 58 women, aged 70 to 94, underwent muscle mass evaluation by dual energy X-ray absorptiometry (DXA), muscle strength evaluation by handgrip, and completed the MSRA, SARC-F and Activity of daily living (ADL) questionnaires. Results: 66 subjects (43.4%) were classified as sarcopenic according to the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. The 7-item SARC-F and MRSA and 5-item MSRA showed an area under the curve (AUC) of 0.666 (95% confidence interval (CI): 0.542–0.789), 0.730 (95% CI: 0.617–0.842) and 0.710 (95% CI: 0.593–0.827), respectively. The optimal cut-off points for sarcopenia detection were determined for each questionnaire using the Youden index method. The newly calculated cut-off points were ≤25 and ≤40 for MSRA 7- and 5-items, respectively. The ideal cut-off for the SARC-F was a score ≥3. Applying this new cut-off in our study population, sensitivity and specificity of the 7-item MSRA were 0.757 and 0.651, and 0.688 and 0.679 for the 5-item MSRA, respectively. Sensitivity and specificity of SARC-F were 0.524 and 0.765, respectively. The combined use of the 7-item SARC-F and MSRA improved the accuracy in sarcopenia diagnosis, with a specificity and sensitivity of 1.00 and 0.636. Conclusion: 7-item SARC-F and MSRA may be co-administered in hospital wards as an easy, feasible, first-line tool to identify sarcopenic subjects. Full article
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13 pages, 2753 KiB  
Article
Camphene Attenuates Skeletal Muscle Atrophy by Regulating Oxidative Stress and Lipid Metabolism in Rats
by Suji Baek, Jisu Kim, Byung Seok Moon, Sun Mi Park, Da Eun Jung, Seo Young Kang, Sang Ju Lee, Seung Jun Oh, Seung Hae Kwon, Myung Hee Nam, Hye Ok Kim, Hai Jeon Yoon, Bom Sahn Kim and Kang Pa Lee
Nutrients 2020, 12(12), 3731; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12123731 - 03 Dec 2020
Cited by 16 | Viewed by 4317
Abstract
Sarcopenia- or cachexia-related muscle atrophy is due to imbalanced energy metabolism and oxidative stress-induced muscle dysfunction. Monoterpenes play biological and pharmacological reactive oxygen species (ROS) scavenging roles. Hence, we explored the effects of camphene, a bicyclic monoterpene, on skeletal muscle atrophy in vitro [...] Read more.
Sarcopenia- or cachexia-related muscle atrophy is due to imbalanced energy metabolism and oxidative stress-induced muscle dysfunction. Monoterpenes play biological and pharmacological reactive oxygen species (ROS) scavenging roles. Hence, we explored the effects of camphene, a bicyclic monoterpene, on skeletal muscle atrophy in vitro and in vivo. We treated L6 myoblast cells with camphene and then examined the ROS-related oxidative stress using Mito TrackerTM Red FM and anti-8-oxoguanine antibody staining. To investigate lipid metabolism, we performed real-time polymerase chain reactions, holotomographic microscopy, and respiratory gas analysis. Rat muscle atrophy in in vivo models was observed using 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography and immunocytochemistry. Camphene reversed the aberrant cell size and muscle morphology of L6 myoblasts under starvation and in in vivo models. Camphene also attenuated E3 ubiquitin ligase muscle RING-finger protein-1, mitochondrial fission, and 8-oxoguanine nuclear expression in starved myotubes and hydrogen peroxide (H2O2)-treated cells. Moreover, camphene significantly regulated lipid metabolism in H2O2-treated cells and in vivo models. These findings suggest that camphene may potentially affect skeletal muscle atrophy by regulating oxidative stress and lipid metabolism. Full article
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14 pages, 295 KiB  
Article
Effect of Dairy Protein Intake on Muscle Mass among Korean Adults: A Prospective Cohort Study
by Eunjin So and Hyojee Joung
Nutrients 2020, 12(9), 2537; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12092537 - 21 Aug 2020
Cited by 4 | Viewed by 3058
Abstract
This cohort study aimed to identify the associations of dairy protein intake with the risk of developing a low muscle mass during a 12-year follow-up period, using data from 4412 middle-aged Korean Genome and Epidemiology Study participants with a normal baseline muscle mass. [...] Read more.
This cohort study aimed to identify the associations of dairy protein intake with the risk of developing a low muscle mass during a 12-year follow-up period, using data from 4412 middle-aged Korean Genome and Epidemiology Study participants with a normal baseline muscle mass. Dairy protein intake at baseline was assessed using a semi-quantitative Food Frequency Questionnaire. Skeletal muscle mass index (SMI), defined as the weight-adjusted skeletal muscle mass, was measured biennially using multi-frequency bioelectrical impedance analyses. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Overall, 395 subjects developed a low SMI (%) during an average follow-up of 141 (19–152) months. The average consumption of milk and other dairy products was 73.6 and 104.1 g/day, respectively. In men, a higher dairy protein intake was associated with a decreased risk of developing a low SMI (tertile 3 [T3] vs. T1, HR: 0.63; 95% CI: 0.42, 0.94; p for trend = 0.029). In a stratified analysis according to a total protein intake, this association was stronger in the lower-protein intake group (HR: 0.59; 95% CI: 0.35, 0.99; p for trend = 0.036) but not detected in the higher-protein intake group. Men who consumed milk ≥1 time/day had a significantly lower risk of developing a low SMI (HR: 0.62; 95% CI: 0.39, 0.98; p for trend = 0.023). No significant associations were observed in women. In summary, dairy consumption appears to be beneficial for decreasing the risk of developing a low muscle mass in middle-aged Korean men. Full article
18 pages, 2172 KiB  
Article
Overfeeding and Substrate Availability, But Not Age or BMI, Alter Human Satellite Cell Function
by Dane W. Fausnacht, Ryan P. McMillan, Nabil E. Boutagy, Ryan A. Lupi, Mordecai M. Harvey, Brenda M. Davy, Kevin P. Davy, Robert P. Rhoads and Matthew W. Hulver
Nutrients 2020, 12(8), 2215; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12082215 - 24 Jul 2020
Cited by 3 | Viewed by 2386
Abstract
Satellite cells (SC) aid skeletal muscle growth and regeneration. SC-mediated skeletal muscle repair can both be influenced by and exacerbate several diseases linked to a fatty diet, obesity, and aging. The purpose of this study was to evaluate the effects of different lifestyle [...] Read more.
Satellite cells (SC) aid skeletal muscle growth and regeneration. SC-mediated skeletal muscle repair can both be influenced by and exacerbate several diseases linked to a fatty diet, obesity, and aging. The purpose of this study was to evaluate the effects of different lifestyle factors on SC function, including body mass index (BMI), age, and high-fat overfeeding. For this study, SCs were isolated from the vastus lateralis of sedentary young (18–30 years) and sedentary older (60–80 years) men with varying BMIs (18–32 kg/m2), as well as young sedentary men before and after four weeks of overfeeding (OVF) (55% fat/ + 1000 kcal, n = 4). The isolated SCs were then treated in vitro with a control (5 mM glucose, 10% fetal bovine serum (FBS)) or a high substrate growth media (HSM) (10% FBS, 25 mM glucose, and 400 μM 2:1 oleate–palmitate). Cells were assessed on their ability to proliferate, differentiate, and fuel substrate oxidation after differentiation. The effect of HSM was measured as the percentage difference between SCs exposed to HSM compared to control media. In vitro SC function was not affected by donor age. OVF reduced SC proliferation rates (–19% p < 0.05) but did not influence differentiation. Cellular proliferation in response to HSM was correlated to the donor’s body mass index (BMI) (r2 = 0.6121, p < 0.01). When exposed to HSM, SCs from normal weight (BMI 18–25 kg/m2) participants exhibited reduced proliferation and fusion rates with increased fatty-acid oxidation (p < 0.05), while SCs from participants with higher BMIs (BMI 25–32 kg/m2) demonstrated enhanced proliferation in HSM. HSM reduced proliferation and fusion (p < 0.05) in SCs isolated from subjects before OVF, whereas HSM exposure accelerated proliferation and fusion in SCs collected following OVF. These results indicated that diet has a greater influence on SC function than age and BMI. Though age and BMI do not influence in vitro SC function when grown in controlled conditions, both factors influenced the response of SCs to substrate challenges, indicating age and BMI may mediate responses to diet. Full article
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13 pages, 1430 KiB  
Article
Vitamin D Inhibits Myogenic Cell Fusion and Expression of Fusogenic Genes
by Tohru Hosoyama, Hiroki Iida, Minako Kawai-Takaishi and Ken Watanabe
Nutrients 2020, 12(8), 2192; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12082192 - 23 Jul 2020
Cited by 8 | Viewed by 3969
Abstract
Vitamin D, a fat-soluble vitamin, is an important nutrient for tissue homeostasis and is recently gaining attention for its role in sarcopenia. Although several studies have focused on the role of vitamin D in muscle homeostasis, the molecular mechanism underlying its action on [...] Read more.
Vitamin D, a fat-soluble vitamin, is an important nutrient for tissue homeostasis and is recently gaining attention for its role in sarcopenia. Although several studies have focused on the role of vitamin D in muscle homeostasis, the molecular mechanism underlying its action on skeletal muscle remains unclear. This study investigated the role of vitamin D in myogenesis and muscle fiber maintenance in an immortalized mouse myogenic cell line. A high concentration of active vitamin D, 1α,25(OH)2D3, decreased the expression of myogenic regulatory factors (MRFs), myf5 and myogenin in proliferating myoblasts. In addition, high concentration of vitamin D reduced myoblast-to-myoblast and myoblast-to-myotube fusion through the inhibition of Tmem8c (myomaker) and Gm7325 (myomerger), which encode muscle-specific fusion-related micropeptides. A similar inhibitory effect of vitamin D was also observed in immortalized human myogenic cells. A high concentration of vitamin D also induced hypertrophy of multinucleated myotubes by stimulating protein anabolism. The results from this study indicated that vitamin D had both positive and negative effects on muscle homeostasis, such as in muscle regeneration and myofiber maintenance. Elderly individuals face a higher risk of falling and suffering fractures; hence, administration of vitamin D for treating fractures in the elderly could actually promote fusion impairment and, consequently, severe defects in muscle regeneration. Therefore, our results suggest that vitamin D replacement therapy should be used for prevention of age-related muscle loss, rather than for treatment of sarcopenia. Full article
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13 pages, 768 KiB  
Article
Amount of Protein Required to Improve Muscle Mass in Older Adults
by Doyeon Kim and Yongsoon Park
Nutrients 2020, 12(6), 1700; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12061700 - 06 Jun 2020
Cited by 6 | Viewed by 5787
Abstract
Increased protein intake has been suggested as an effective strategy to treat age-related loss of muscle mass and function, but the amount of protein required to improve muscle and function without exercise in older adults remains unclear. Thus, this secondary data analysis aimed [...] Read more.
Increased protein intake has been suggested as an effective strategy to treat age-related loss of muscle mass and function, but the amount of protein required to improve muscle and function without exercise in older adults remains unclear. Thus, this secondary data analysis aimed to assess what amount of protein from habitual protein intake was positively associated with changes in muscle mass and gait speed in older women and men. Ninety-six community-dwelling older adults consumed 0.8, 1.2, or 1.5 g/kg/day of protein and maintained their usual physical activity for 12 weeks. Increased protein intake of >0.54 g/kg/day was positively associated with changes in appendicular skeletal muscle mass (ASM)/weight (B = 0.591, p = 0.026), ASM/body mass index (B = 0.615, p = 0.023), and ASM:fat ratio (B = 0.509, p = 0.030) in older men. However, change in protein intake was not associated with change in muscle mass in older women. Additionally, change in protein intake was not associated with change in gait speed in older women and men. The present study suggested that an increased absolute protein amount of >0.54 g/kg/day from habitual protein intake was positively associated with change in muscle mass in older men. Full article
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16 pages, 671 KiB  
Article
Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical Trial
by Francisco M. Martínez-Arnau, Rosa Fonfría-Vivas, Cristina Buigues, Yolanda Castillo, Pilar Molina, Aldert J. Hoogland, Femke van Doesburg, Leo Pruimboom, Julio Fernández-Garrido and Omar Cauli
Nutrients 2020, 12(4), 932; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12040932 - 27 Mar 2020
Cited by 58 | Viewed by 12414
Abstract
Treating sarcopenia in older individuals remains a challenge, and nutritional interventions present promising approaches in individuals that perform limited physical exercise. We assessed the efficacy of leucine administration to evaluate whether the regular intake of this essential amino acid can improve muscle mass, [...] Read more.
Treating sarcopenia in older individuals remains a challenge, and nutritional interventions present promising approaches in individuals that perform limited physical exercise. We assessed the efficacy of leucine administration to evaluate whether the regular intake of this essential amino acid can improve muscle mass, muscle strength and functional performance and respiratory muscle function in institutionalized older individuals. The study was a placebo-controlled, randomized, double-blind design in fifty participants aged 65 and over (ClinicalTrials.gov identifier NCT03831399). The participants were randomized to a parallel group intervention of 13 weeks’ duration with a daily intake of leucine (6 g/day) or placebo (lactose, 6 g/day). The primary outcome was to study the effect on sarcopenia and respiratory muscle function. The secondary outcomes were changes in the geriatric evaluation scales, such as cognitive function, functional impairment and nutritional assessments. We also evaluated whether leucine administration alters blood analytical parameters and inflammatory markers. Administration of leucine was well-tolerated and significantly improves some criteria of sarcopenia in elderly individuals such as functional performance measured by walking time (p = 0.011), and improved lean mass index. For respiratory muscle function, the leucine-treated group improved significantly (p = 0.026) in maximum static expiratory force compared to the placebo. No significant effects on functional impairment, cognitive function or nutritional assessment, inflammatory cytokines IL-6, TNF-alpha were observed after leucine administration compared to the placebo. The use of l-leucine supplementation can have some beneficial effects on sarcopenia and could be considered for the treatment of sarcopenia in older individuals. Full article
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Review

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20 pages, 1329 KiB  
Review
Antioxidants in Sport Sarcopenia
by Maria Michela Cesare, Francesca Felice, Veronica Santini and Rossella Di Stefano
Nutrients 2020, 12(9), 2869; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12092869 - 19 Sep 2020
Cited by 8 | Viewed by 4685
Abstract
The decline of skeletal muscle mass and strength that leads to sarcopenia is a pathology that might represent an emergency healthcare issue in future years. Decreased muscle mass is also a condition that mainly affects master athletes involved in endurance physical activities. Skeletal [...] Read more.
The decline of skeletal muscle mass and strength that leads to sarcopenia is a pathology that might represent an emergency healthcare issue in future years. Decreased muscle mass is also a condition that mainly affects master athletes involved in endurance physical activities. Skeletal muscles respond to exercise by reshaping the biochemical, morphological, and physiological state of myofibrils. Adaptive responses involve the activation of intracellular signaling pathways and genetic reprogramming, causing alterations in contractile properties, metabolic status, and muscle mass. One of the mechanisms leading to sarcopenia is an increase in reactive oxygen and nitrogen species levels and a reduction in enzymatic antioxidant protection. The present review shows the recent experimental models of sarcopenia that explore molecular mechanisms. Furthermore, the clinical aspect of sport sarcopenia will be highlighted, and new strategies based on nutritional supplements, which may contribute to reducing indices of oxidative stress by reinforcing natural endogenous protection, will be suggested. Full article
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21 pages, 741 KiB  
Review
A Call to Action: Now Is the Time to Screen Elderly and Treat Osteosarcopenia, a Position Paper of the Italian College of Academic Nutritionists MED/49 (ICAN-49)
by Tiziana Montalcini, Arturo Pujia, Lorenzo M. Donini, Lucia Frittitta, Fabio Galvano, Andrea Natali, Loris Pironi, Marisa Porrini, Patrizia Riso, Angela Albarosa Rivellese, Diego Russo, Giovanni Scapagnini, Mauro Serafini, Anna Tagliabue and Antonino De Lorenzo
Nutrients 2020, 12(9), 2662; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12092662 - 31 Aug 2020
Cited by 11 | Viewed by 6323
Abstract
Aging is a risk factor for the development of multiple chronic diseases, including cardiovascular disease, cancer and dementia. Life expectancy has increased in certain countries but this phenomenon is associated with a reduction of years of healthy life. Aging is associated with a [...] Read more.
Aging is a risk factor for the development of multiple chronic diseases, including cardiovascular disease, cancer and dementia. Life expectancy has increased in certain countries but this phenomenon is associated with a reduction of years of healthy life. Aging is associated with a number of physical and functional changes, especially sarcopenia. Sarcopenia is a clinical condition associated with a decrease in skeletal muscle and muscle strength, however, sarcopenia is a reversible condition. On the basis of the current scientific literature, sarcopenia could more appropriately capture an individual’s vulnerability to negative health-related outcomes since it represents an early form of the chronic diseases. Recognition of this clinical condition can improve the management of older individuals in many different clinical settings. Despite the limitations of the indirect methods used to study body composition, the Italian College of the Academic Nutritionists ME/49 recommends that health authorities and health professionals around the world should make a greater effort to diagnose sarcopenia earlier and to manage it more effectively. In line with the development of cancer screening, the use of two diagnostic tools for sarcopenia (BIA and DXA) should be implemented. Full article
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18 pages, 14162 KiB  
Review
Docosahexaenoic Acid, a Potential Treatment for Sarcopenia, Modulates the Ubiquitin–Proteasome and the Autophagy–Lysosome Systems
by Jung Hoon Lee, Jun Hyoung Jeon and Min Jae Lee
Nutrients 2020, 12(9), 2597; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12092597 - 26 Aug 2020
Cited by 32 | Viewed by 5317
Abstract
One of the characteristic features of aging is the progressive loss of muscle mass, a nosological syndrome called sarcopenia. It is also a pathologic risk factor for many clinically adverse outcomes in older adults. Therefore, delaying the loss of muscle mass, through either [...] Read more.
One of the characteristic features of aging is the progressive loss of muscle mass, a nosological syndrome called sarcopenia. It is also a pathologic risk factor for many clinically adverse outcomes in older adults. Therefore, delaying the loss of muscle mass, through either boosting muscle protein synthesis or slowing down muscle protein degradation using nutritional supplements could be a compelling strategy to address the needs of the world’s aging population. Here, we review the recently identified properties of docosahexaenoic acid (DHA). It was shown to delay muscle wasting by stimulating intermediate oxidative stress and inhibiting proteasomal degradation of muscle proteins. Both the ubiquitin–proteasome and the autophagy–lysosome systems are modulated by DHA. Collectively, growing evidence indicates that DHA is a potent pharmacological agent that could improve muscle homeostasis. Better understanding of cellular proteolytic systems associated with sarcopenia will allow us to identify novel therapeutic interventions, such as omega-3 polyunsaturated fatty acids, to treat this disease. Full article
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19 pages, 3341 KiB  
Review
Effects of Protein Supplementation Combined with Exercise Training on Muscle Mass and Function in Older Adults with Lower-Extremity Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Trials
by Chun-De Liao, Yen-Tzu Wu, Jau-Yih Tsauo, Pey-Rong Chen, Yu-Kang Tu, Hung-Chou Chen and Tsan-Hon Liou
Nutrients 2020, 12(8), 2422; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12082422 - 12 Aug 2020
Cited by 23 | Viewed by 5815
Abstract
Aging and osteoarthritis (OA) are associated with a high risk of muscle mass loss, which can lead to physical disability. This study investigated the effectiveness of protein supplementation combined with exercise training (PS + ET) in improving muscle mass and functional outcomes in [...] Read more.
Aging and osteoarthritis (OA) are associated with a high risk of muscle mass loss, which can lead to physical disability. This study investigated the effectiveness of protein supplementation combined with exercise training (PS + ET) in improving muscle mass and functional outcomes in older adults with lower-limb OA. A comprehensive search of online databases was performed to identify randomized controlled trials (RCTs) on the effectiveness of PS + ET in older adults with hip or knee OA. Meta-analysis and risk of bias assessment of the included RCTs were conducted. Six RCTs were included in this systemic review; they had a median (range/total) Physiotherapy Evidence Database (PEDro) score of 7 (6–9) out of 10, respectively. Five RCTs that enrolled patients who underwent total joint replacement were included in this meta-analysis. The PS + ET group exhibited significant improvements in muscle mass (standard mean difference [SMD] = 1.13, p < 0.00001), pain (SMD = 1.36, p < 0.00001), and muscle strength (SMD = 0.44, p = 0.04). Our findings suggest that PS + ET improves muscle mass, muscle strength, and functional outcomes and reduces pain in older adults with lower-limb OA, particularly in those who have undergone total joint replacement. Full article
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22 pages, 687 KiB  
Review
Myostatin as a Biomarker of Muscle Wasting and other Pathologies-State of the Art and Knowledge Gaps
by Jan Baczek, Marta Silkiewicz and Zyta Beata Wojszel
Nutrients 2020, 12(8), 2401; https://0-doi-org.brum.beds.ac.uk/10.3390/nu12082401 - 11 Aug 2020
Cited by 70 | Viewed by 6992
Abstract
Sarcopenia is a geriatric syndrome with a significant impact on older patients’ quality of life, morbidity and mortality. Despite the new available criteria, its early diagnosis remains difficult, highlighting the necessity of looking for a valid muscle wasting biomarker. Myostatin, a muscle mass [...] Read more.
Sarcopenia is a geriatric syndrome with a significant impact on older patients’ quality of life, morbidity and mortality. Despite the new available criteria, its early diagnosis remains difficult, highlighting the necessity of looking for a valid muscle wasting biomarker. Myostatin, a muscle mass negative regulator, is one of the potential candidates. The aim of this work is to point out various factors affecting the potential of myostatin as a biomarker of muscle wasting. Based on the literature review, we can say that recent studies produced conflicting results and revealed a number of potential confounding factors influencing their use in sarcopenia diagnosing. These factors include physiological variables (such as age, sex and physical activity) as well as a variety of disorders (including heart failure, metabolic syndrome, kidney failure and inflammatory diseases) and differences in laboratory measurement methodology. Our conclusion is that although myostatin alone might not prove to be a feasible biomarker, it could become an important part of a recently proposed panel of muscle wasting biomarkers. However, a thorough understanding of the interrelationship of these markers, as well as establishing a valid measurement methodology for myostatin and revising current research data in the light of new criteria of sarcopenia, is needed. Full article
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