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Yamada Y, Watanabe K, Fujisawa C, Komiya H, Nakashima H, Tajima T, Umegaki H. Relationship between cognitive function and phase angle measured with a bioelectrical impedance system. Eur Geriatr Med 2024; 15:201-208. [PMID: 38015386 DOI: 10.1007/s41999-023-00894-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 10/27/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE The purpose of this study was to investigate the relationship between cognitive function and phase angle (PhA), an indicator of muscle quality. METHODS This cross-sectional study enrolled outpatients who visited a memory clinic at the Nagoya University hospital from January 2016 to June 2022. We enrolled 153 participants with body composition measurements. Inclusion criteria were a Mini-Mental State Examination score of 20-30 and a clinical diagnosis of Alzheimer's dementia (AD) or amnesic mild cognitive impairment (aMCI). The background characteristics of the participants were compared according to AD and aMCI. Next, linear regression analysis was performed with PhA as the objective variable. In addition, logistic regression analysis was performed for AD diagnosis. RESULTS PhA was lower in the AD group (P = 0.009). In linear regression analysis, PhA consistently decreased with worsening ADAS score. In logistic regression analysis, high PhA was associated with absence of AD. Gender-specific analyses showed these associations existed only in men. CONCLUSIONS Our study of patients with AD and aMCI found that PhA decreased with worsening of cognitive function. Compared with aMCI, AD was associated with significantly lower PhA. Our results strengthen the limited evidence in the literature showing that low muscle quality is associated with poor cognitive function.
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Affiliation(s)
- Yosuke Yamada
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan
| | - Kazuhisa Watanabe
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan
| | - Chisato Fujisawa
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan
| | - Hitoshi Komiya
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan
| | - Hirotaka Nakashima
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan
| | - Tomihiko Tajima
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan
| | - Hiroyuki Umegaki
- Departments of Community Healthcare and Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya City, Aichi, 466-8550, Japan.
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Lim JY, Frontera WR. Skeletal muscle aging and sarcopenia: Perspectives from mechanical studies of single permeabilized muscle fibers. J Biomech 2023; 152:111559. [PMID: 37027961 PMCID: PMC10164716 DOI: 10.1016/j.jbiomech.2023.111559] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The decline in muscle mass and strength with age is well documented and associated with weakness, decreased flexibility, vulnerability to diseases and/or injuries, and impaired functional restoration. The term sarcopenia has been used to refer to the loss of muscle mass, strength and impaired physical performance with advanced adult age and recently has become a major clinical entity in a super-aged society. To understand the pathophysiology and clinical manifestations of sarcopenia, it is essential to explore the age-related changes in the intrinsic properties of muscle fibers. Mechanical experiments with single muscle fibers have been conducted during the last 80 years and applied to human muscle research in the last 45 years as an in-vitro muscle function test. Fundamental active and passive mechanical properties of skeletal muscle can be evaluated using the isolated permeabilized (chemically skinned) single muscle fiber preparation. Changes in the intrinsic properties of older human single muscle fibers can be useful biomarkers of aging and sarcopenia. In this review, we summarize the historical development of single muscle fiber mechanical studies, the definition and diagnosis of muscle aging and sarcopenia, and age-related change of active and passive mechanical properties in single muscle fibers and discuss how these changes can be used to assess muscle aging and sarcopenia.
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Affiliation(s)
- Jae-Young Lim
- Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam-si Gyeonggi-do, South Korea
| | - Walter R Frontera
- Department of Physiology and Department of Physical Medicine, Rehabilitation, and Sports Medicine, University of Puerto Rico School of Medicine, San Juan, Puerto Rico.
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Zeng S, Chang CH, Sun M, Chen WM, Wu SY, Zhang J. Comparison of surgical complications after curative surgery in patients with oral cavity squamous cell carcinoma and sarcopenia. J Cachexia Sarcopenia Muscle 2023; 14:576-584. [PMID: 36562311 PMCID: PMC9891945 DOI: 10.1002/jcsm.13162] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 11/10/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The study aims to clarify the association of sarcopenia with perioperative and postoperative complications in oral cavity squamous cell carcinoma (OCSCC) patients undergoing curative surgery and to understand the reasons causing the poor oncologic outcomes for OCSCC. METHODS We conducted a propensity score matching study to investigate the association of perioperative and postoperative outcomes in OCSCC patients with sarcopenia and without sarcopenia. A retrospective analysis of a large national data set from the Taiwan Cancer Registry Database was conducted. At least two claims for patients with a principal diagnosis of sarcopenia within the 12-month preoperative period were defined as the criteria for sarcopenia diagnosis (ICD-10-CM code M62.84). Sarcopenia was diagnosed through the measurement of low muscle strength and low muscle mass by any one of the patient's attending orthopaedic physician, rehabilitation physician, family medicine specialist or geriatrician. A multivariate logistic regression model was used to calculate the perioperative, and postoperative major complications. RESULTS Our final cohort included 16 293 patients with OCSCC (10 862 and 5 431 in the sarcopenia and nonsarcopenia groups, respectively) who were eligible for further analysis. The sarcopenia group was 10.40% female and 89.60% male, and the nonsarcopenia group was 9.74% female and 90.26% male. The mean age ± standard deviation (SD) were 56.44 ± 11.14 and 56.22 ± 11.29 for sarcopenia and nonsarcopenia groups. OCSCC patients with sarcopenia undergoing curative surgery had a significantly higher blood transfusion rate and volume; longer intensive care unit (ICU) stay, and hospital stay; higher postoperative 30-day mortality (adjusted odds ratio [aOR]: 1.12, 95% confidence interval [CI] [1.07, 1.56]) and rates of pneumonia (aOR: 1.34, 95% CI [1.20, 1.50]), acute renal failure (aOR: 1.45, 95% CI [1.12, 1.87]) and septicaemia (aOR: 1.29, 95% CI [1.15, 1.45]); higher postoperative first-year mortality (aOR: 1.18, 95% CI [1.13, 1.51]) and rates of pneumonia (aOR: 1.43, 95% CI [1.30, 1.56]), acute myocardial infarction (aOR: 1.52, 95% CI [1.06, 2.18]) and septicaemia (aOR: 1.29, 95% CI [1.15, 1.45]). CONCLUSIONS OCSCC patients with sarcopenia might exhibit more perioperative and surgical complications than those without sarcopenia.
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Affiliation(s)
- Shuang Zeng
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Academy of Medical Sciences of Zhengzhou University, Zhengzhou, Henan, China
| | - Chia-Hao Chang
- Department of Otorhinolaryngology, Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital, Luodong, Taiwan
| | - Mingyang Sun
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Wan-Ming Chen
- Graduate Institute of Business Administration, College of Management, Fu Jen Catholic University, Taipei, Taiwan.,Artificial Intelligence Development Center, Fu Jen Catholic University, Taipei, Taiwan
| | - Szu-Yuan Wu
- Graduate Institute of Business Administration, College of Management, Fu Jen Catholic University, Taipei, Taiwan.,Artificial Intelligence Development Center, Fu Jen Catholic University, Taipei, Taiwan.,Department of Food Nutrition and Health Biotechnology, College of Medical and Health Science, Asia University, Taichung, Taiwan.,Big Data Center, Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital, Luodong, Yilan, Taiwan.,Division of Radiation Oncology, Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital, Luodong, Taiwan.,Department of Healthcare Administration, College of Medical and Health Science, Asia University, Taichung, Taiwan.,Cancer Center, Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital, Luodong, Taiwan.,Centers for Regional Anesthesia and Pain Medicine, Taipei Municipal Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Management, College of Management, Fo Guang University, Jiaoxi, Taiwan
| | - Jiaqiang Zhang
- Department of Anesthesiology and Perioperative Medicine, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, Henan, China
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Abstract
Ageing is accompanied by decrements in the size and function of skeletal muscle that compromise independence and quality of life in older adults. Developing therapeutic strategies to ameliorate these changes is critical but requires an in-depth mechanistic understanding of the underlying physiology. Over the past 25 years, studies on the contractile mechanics of isolated human muscle fibres have been instrumental in facilitating our understanding of the cellular mechanisms contributing to age-related skeletal muscle dysfunction. The purpose of this review is to characterize the changes that occur in single muscle fibre size and contractile function with ageing and identify key areas for future research. Surprisingly, most studies observe that the size and contractile function of fibres expressing slow myosin heavy chain (MHC) I are well-preserved with ageing. In contrast, there are profound age-related decrements in the size and contractile function of the fibres expressing the MHC II isoforms. Notably, lifelong aerobic exercise training is unable to prevent most of the decrements in fast fibre contractile function, which have been implicated as a primary mechanism for the age-related loss in whole-muscle power output. These findings reveal a critical need to investigate the effectiveness of other nutritional, pharmaceutical or exercise strategies, such as lifelong resistance training, to preserve fast fibre size and function with ageing. Moreover, integrating single fibre contractile mechanics with the molecular profile and other parameters important to contractile function (e.g. phosphorylation of regulatory proteins, innervation status, mitochondrial function, fibre economy) is necessary to comprehensively understand the ageing skeletal muscle phenotype.
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Affiliation(s)
- Gregory J. Grosicki
- Biodynamics and Human Performance Center, Georgia Southern University (Armstrong Campus), Savannah, Georgia, USA
| | - Carlos S. Zepeda
- Exercise and Rehabilitation Sciences Graduate Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA
| | - Christopher W. Sundberg
- Exercise and Rehabilitation Sciences Graduate Program, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, USA
- Athletic and Human Performance Research Center, Marquette University, Milwaukee, Wisconsin, USA
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Ghzaiel I, Zarrouk A, Essadek S, Martine L, Hammouda S, Yammine A, Ksila M, Nury T, Meddeb W, Tahri Joutey M, Mihoubi W, Caccia C, Leoni V, Samadi M, Acar N, Andreoletti P, Hammami S, Ghrairi T, Vejux A, Hammami M, Lizard G. Protective effects of milk thistle (Sylibum marianum) seed oil and α-tocopherol against 7β-hydroxycholesterol-induced peroxisomal alterations in murine C2C12 myoblasts: Nutritional insights associated with the concept of pexotherapy. Steroids 2022; 183:109032. [PMID: 35381271 DOI: 10.1016/j.steroids.2022.109032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/15/2022] [Accepted: 03/31/2022] [Indexed: 12/11/2022]
Abstract
Peroxisomes play an important role in regulating cell metabolism and RedOx homeostasis. Peroxisomal dysfunctions favor oxidative stress and cell death. The ability of 7β-hydroxycholesterol (7β-OHC; 50 μM, 24 h), known to be increased in patients with age-related diseases such as sarcopenia, to trigger oxidative stress, mitochondrial and peroxisomal dysfunction was studied in murine C2C12 myoblasts. The capacity of milk thistle seed oil (MTSO, 100 μg/mL) as well as α-tocopherol (400 µM; reference cytoprotective agent) to counteract the toxic effects of 7β-OHC, mainly at the peroxisomal level were evaluated. The impacts of 7β-OHC, in the presence or absence of MTSO or α-tocopherol, were studied with complementary methods: measurement of cell density and viability, quantification of reactive oxygen species (ROS) production and transmembrane mitochondrial potential (ΔΨm), evaluation of peroxisomal mass as well as topographic, morphologic and functional peroxisomal changes. Our results indicate that 7β-OHC induces a loss of cell viability and a decrease of cell adhesion associated with ROS overproduction, alterations of mitochondrial ultrastructure, a drop of ΔΨm, and several peroxisomal modifications. In the presence of 7β-OHC, comparatively to untreated cells, important quantitative and qualitative peroxisomal modifications were also identified: a) a reduced number of peroxisomes with abnormal sizes and shapes, mainly localized in cytoplasmic vacuoles, were observed; b) the peroxisomal mass was decreased as indicated by lower protein and mRNA levels of the peroxisomal ABCD3 transporter; c) lower mRNA level of Pex5 involved in peroxisomal biogenesis as well as higher mRNA levels of Pex13 and Pex14, involved in peroxisomal biogenesis and/or pexophagy, was found; d) lower levels of ACOX1 and MFP2 enzymes, implicated in peroxisomal β-oxidation, were detected; e) higher levels of very-long-chain fatty acids, which are substrates of peroxisomal β-oxidation, were found. These different cytotoxic effects were strongly attenuated by MTSO, in the same range of order as with α-tocopherol. These findings underline the interest of MTSO and α-tocopherol in the prevention of peroxisomal damages (pexotherapy).
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Affiliation(s)
- Imen Ghzaiel
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France; Lab-NAFS 'Nutrition-Functional Food & Vascular Health', Faculty of Medicine, University of Monastir, LR12ES05, 5000 Monastir, Tunisia; Faculty of Sciences of Tunis, University Tunis-El Manar, 2092 Tunis, Tunisia
| | - Amira Zarrouk
- Lab-NAFS 'Nutrition-Functional Food & Vascular Health', Faculty of Medicine, University of Monastir, LR12ES05, 5000 Monastir, Tunisia; Faculty of Medicine, University of Sousse, 4000 Sousse, Tunisia.
| | - Soukaina Essadek
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France; Laboratory of Biochemistry, Neurosciences, Natural Resources and Environment, Faculty of Sciences & Techniques, University Hassan I, BP 577, 26000 Settat, Morocco
| | - Lucy Martine
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, 21065 Dijon, France
| | - Souha Hammouda
- Lab-NAFS 'Nutrition-Functional Food & Vascular Health', Faculty of Medicine, University of Monastir, LR12ES05, 5000 Monastir, Tunisia
| | - Aline Yammine
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France; Bioactive Molecules Research Laboratory, Doctoral School of Sciences and Technologies, Faculty of Sciences, Lebanese University, Fanar, Jdeidet P.O. Box 90656, Lebanon
| | - Mohamed Ksila
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France; Faculty of Sciences of Tunis, University Tunis-El Manar, 2092 Tunis, Tunisia
| | - Thomas Nury
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France
| | - Wiem Meddeb
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France
| | - Mounia Tahri Joutey
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France; Laboratory of Biochemistry, Neurosciences, Natural Resources and Environment, Faculty of Sciences & Techniques, University Hassan I, BP 577, 26000 Settat, Morocco
| | - Wafa Mihoubi
- Laboratoire de Biotechnologie Moléculaire des Eucaryotes, Centre de Biotechnologie de Sfax, B.P 1177, Université de Sfax, 3018 Sfax, Tunisia
| | - Claudio Caccia
- Laboratory of Clinical Chemistry, Hospitals of Desio, ASST-Brianza and Department of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Valerio Leoni
- Laboratory of Clinical Chemistry, Hospitals of Desio, ASST-Brianza and Department of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Mohammad Samadi
- LCPMC-A2, ICPM, Department of Chemistry, University Lorraine, Metz Technopôle, 57070 Metz, France
| | - Niyazi Acar
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, 21065 Dijon, France
| | - Pierre Andreoletti
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France
| | - Sonia Hammami
- Lab-NAFS 'Nutrition-Functional Food & Vascular Health', Faculty of Medicine, University of Monastir, LR12ES05, 5000 Monastir, Tunisia
| | - Taoufik Ghrairi
- Faculty of Sciences of Tunis, University Tunis-El Manar, 2092 Tunis, Tunisia
| | - Anne Vejux
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France
| | - Mohamed Hammami
- Lab-NAFS 'Nutrition-Functional Food & Vascular Health', Faculty of Medicine, University of Monastir, LR12ES05, 5000 Monastir, Tunisia
| | - Gérard Lizard
- Team 'Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism'EA7270/Inserm, University Bourgogne Franche-Comté, 21000 Dijon, France.
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Hart DA. Sex Differences in Biological Systems and the Conundrum of Menopause: Potential Commonalities in Post-Menopausal Disease Mechanisms. Int J Mol Sci 2022; 23:ijms23084119. [PMID: 35456937 PMCID: PMC9026302 DOI: 10.3390/ijms23084119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/30/2022] [Accepted: 04/05/2022] [Indexed: 02/04/2023] Open
Abstract
Sex-specific differences in biology and physiology likely start at the time of conception and progress and mature during the pre-puberty time frame and then during the transitions accompanying puberty. These sex differences are impacted by both genetics and epigenetic alterations during the maturation process, likely for the purpose of preparing for successful reproduction. For females, later in life (~45–50) they undergo another transition leading to a loss of ovarian hormone production at menopause. The reasons for menopause are not clear, but for a subset of females, menopause is accompanied by an increased risk of a number of diseases or conditions that impact a variety of tissues. Most research has mainly focused on the target cells in each of the affected tissues rather than pursue the alternative option that there may be commonalities in the development of these post-menopausal conditions in addition to influences on specific target cells. This review will address some of the potential commonalities presented by an integration of the literature regarding tissue-specific aspects of these post-menopausal conditions and data presented by space flight/microgravity (a condition not anticipated by evolution) that could implicate a loss of a regulatory function of the microvasculature in the risk attached to the affected tissues. Thus, the loss of the integration of the paracrine relationships between endothelial cells of the microvasculature of the tissues affected in the post-menopausal environment could contribute to the risk for post-menopausal diseases/conditions. The validation of this concept could lead to new approaches for interventions to treat post-menopausal conditions, as well as provide new understanding regarding sex-specific biological regulation.
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Affiliation(s)
- David A. Hart
- Department of Surgery and Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 4N1, Canada; ; Tel.: +1-403-220-4571
- Bone & Joint Health Strategic Clinical Network, Alberta Health Services, Edmonton, AB T5J 3E4, Canada
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Frontera WR. Rehabilitation of Older Adults with Sarcopenia: From Cell to Functioning. Prog Rehabil Med 2022; 7:20220044. [PMID: 36118146 PMCID: PMC9437741 DOI: 10.2490/prm.20220044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 08/16/2022] [Indexed: 11/11/2022] Open
Abstract
The 20th and 21st centuries have witnessed a substantial increase in human life
expectancy and in the number of men and women aged 60 years and older. Aging is associated
with a large number of health conditions, including sarcopenia, which has been the subject
of important research in the past 30 years. Sarcopenia is characterized by an age-related
loss of muscle mass, weakness, and impaired physical performance. The condition can be
diagnosed with a combination of measurements of these three elements. The precise
definition of sarcopenia and the selection of optimal assessment methods have changed
significantly in the past 20 years; nonetheless, the prevalence of sarcopenia in the
general older population is in the range of 5–15%. Molecular and cellular events at the
muscle cell level impact the size and quality of muscles (force adjusted for size). The
active and passive mechanical properties of single muscle fibers are altered by changes in
the structure and function of various cellular elements. Systemic factors such as
inflammation, loss of hormonal influence, and deleterious lifestyle choices also
contribute to sarcopenia. The consequences of sarcopenia include many adverse effects such
as impairments in activities of daily living, falls, loss of independence, and increased
mortality. Several rehabilitative interventions have been tested, and the safest and most
effective is the use of progressive resistance exercise. An increase in dietary protein
intake has synergistic effects. Future research should focus on a consensus definition of
sarcopenia, identification of the best assessment methods, understanding of biological
mechanisms, and testing of innovative interventions.
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Affiliation(s)
- Walter R. Frontera
- Department of Physical Medicine, Rehabilitation, and Sports Medicine/Department of Physiology, University of Puerto Rico School of Medicine, San Juan, Puerto Rico, USA
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