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11C-L-methyl methionine dynamic PET/CT of skeletal muscle: response to protein supplementation compared to L-[ring 13C 6] phenylalanine infusion with serial muscle biopsy. Ann Nucl Med 2017; 31:295-303. [PMID: 28260185 PMCID: PMC5397459 DOI: 10.1007/s12149-017-1157-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 02/01/2017] [Indexed: 01/12/2023]
Abstract
Objective The objective of this study was to determine if clinical dynamic PET/CT imaging with 11C-L-methyl-methionine (11C-MET) in healthy older women can provide an estimate of tissue-level post-absorptive and post-prandial skeletal muscle protein synthesis that is consistent with the more traditional method of calculating fractional synthesis rate (FSR) of muscle protein synthesis from skeletal muscle biopsies obtained during an infusion of L-[ring 13C6] phenylalanine (13C6-Phe). Methods Healthy older women (73 ± 5 years) completed both dynamic PET/CT imaging with 11C-MET and a stable isotope infusion of 13C6-Phe with biopsies to measure the skeletal muscle protein synthetic response to 25 g of a whey protein supplement. Graphical estimation of the Patlak coefficient Ki from analysis of the dynamic PET/CT images was employed as a measure of incorporation of 11 C-MET in the mid-thigh muscle bundle. Results Post-prandial values [mean ± standard error of the mean (SEM)] were higher than post-absorptive values for both Ki (0.0095 ± 0.001 vs. 0.00785 ± 0.001 min−1, p < 0.05) and FSR (0.083 ± 0.008 vs. 0.049 ± 0.006%/h, p < 0.001) in response to the whey protein supplement. The percent increase in Ki and FSR in response to the whey protein supplement was significantly correlated (r = 0.79, p = 0.015). Conclusions Dynamic PET/CT imaging with 11C-MET provides an estimate of the post-prandial anabolic response that is consistent with a traditional, invasive stable isotope, and muscle biopsy approach. These results support the potential future use of 11C-MET imaging as a non-invasive method for assessing conditions affecting skeletal muscle protein synthesis.
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102
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Paddon-Jones D, Coss-Bu JA, Morris CR, Phillips SM, Wernerman J. Variation in Protein Origin and Utilization: Research and Clinical Application. Nutr Clin Pract 2017; 32:48S-57S. [PMID: 28388379 DOI: 10.1177/0884533617691244] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Muscle health can be rapidly compromised in clinical environments. Modifiable strategies to preserve metabolic homeostasis in adult patient populations include physical activity and pharmacologic support; however, optimizing dietary practices, or more specifically protein intake, is a necessary prerequisite for any other treatment strategy to be fully effective. Simply increasing protein intake is a well-intentioned but often unfocused strategy to protect muscle health in an intensive care setting. Protein quality is a frequently overlooked factor with the potential to differentially influence health outcomes. Quality can be assessed by a variety of techniques, with digestible indispensable amino acid score being the current and most comprehensive technique endorsed by the Food and Agriculture Organization. In practical terms, animal-based proteins are consistently scored higher in quality compared with incomplete proteins, regardless of the assessment method. Consequently, choosing parenteral and/or enteral feeding options that contain high-quality proteins, rich in the branched-chain amino acid leucine, may help establish a dietary framework with the potential to support clinical practice and improve health outcomes in critically ill patients.
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Affiliation(s)
- Douglas Paddon-Jones
- 1 Department of Nutrition and Metabolism, The University of Texas Medical Branch, Galveston, Texas, USA
| | - Jorge A Coss-Bu
- 2 Pediatrics Critical Care, Baylor College of Medicine, Houston, Texas, USA
| | - Claudia R Morris
- 3 Division of Pediatric Emergency Medicine, Emory School of Medicine, Atlanta, Georgia, USA
| | - Stuart M Phillips
- 4 Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Jan Wernerman
- 5 Department of Clinical Science, Karolinska University, Solna, Sweden
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Towards human exploration of space: the THESEUS review series on muscle and bone research priorities. NPJ Microgravity 2017. [PMID: 28649630 PMCID: PMC5445590 DOI: 10.1038/s41526-017-0013-0] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Without effective countermeasures, the musculoskeletal system is altered by the microgravity environment of long-duration spaceflight, resulting in atrophy of bone and muscle tissue, as well as in deficits in the function of cartilage, tendons, and vertebral disks. While inflight countermeasures implemented on the International Space Station have evidenced reduction of bone and muscle loss on low-Earth orbit missions of several months in length, important knowledge gaps must be addressed in order to develop effective strategies for managing human musculoskeletal health on exploration class missions well beyond Earth orbit. Analog environments, such as bed rest and/or isolation environments, may be employed in conjunction with large sample sizes to understand sex differences in countermeasure effectiveness, as well as interaction of exercise with pharmacologic, nutritional, immune system, sleep and psychological countermeasures. Studies of musculoskeletal biomechanics, involving both human subject and computer simulation studies, are essential to developing strategies to avoid bone fractures or other injuries to connective tissue during exercise and extravehicular activities. Animal models may be employed to understand effects of the space environment that cannot be modeled using human analog studies. These include studies of radiation effects on bone and muscle, unraveling the effects of genetics on bone and muscle loss, and characterizing the process of fracture healing in the mechanically unloaded and immuno-compromised spaceflight environment. In addition to setting the stage for evidence-based management of musculoskeletal health in long-duration space missions, the body of knowledge acquired in the process of addressing this array of scientific problems will lend insight into the understanding of terrestrial health conditions such as age-related osteoporosis and sarcopenia.
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104
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Cholewa JM, Dardevet D, Lima-Soares F, de Araújo Pessôa K, Oliveira PH, Dos Santos Pinho JR, Nicastro H, Xia Z, Cabido CET, Zanchi NE. Dietary proteins and amino acids in the control of the muscle mass during immobilization and aging: role of the MPS response. Amino Acids 2017; 49:811-820. [PMID: 28175999 DOI: 10.1007/s00726-017-2390-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 01/28/2017] [Indexed: 12/14/2022]
Abstract
Dietary proteins/essential amino acids (EAAs) are nutrients with anabolic properties that may increase muscle mass or attenuate muscle loss during immobilization and aging via the stimulation of muscle protein synthesis (MPS). An EAA's anabolic threshold, capable to maximize the stimulation of MPS has been hypothesized, but during certain conditions associated with muscle loss, this anabolic threshold seems to increase which reduces the efficacy of dietary EAAs to stimulate MPS. Preliminary studies have demonstrated that acute ingestion of dietary proteins/EAA (with a sufficient amount of leucine) was capable to restore the postprandial MPS during bed rest, immobilization or aging; however, whether these improvements translate into chronic increases (or attenuates loss) of muscle mass is equivocal. For example, although free leucine supplementation acutely increases MPS and muscle mass in some chronic studies, other studies have reported no increases in muscle mass following chronic leucine supplementation. In contrast, chronically increasing leucine intake via the consumption of an overall increase in dietary protein appears to be the most effective dietary intervention toward increasing or attenuating lean mass during aging; however, more research investigating the optimal dose and timing of protein ingestion is necessary. Several studies have demonstrated that decreases in postprandial MPS as a result of increased circulating oxidative and inflammatory are more responsible than muscle protein breakdown for the decreases in muscle mass during disuse and health aging. Therefore, nutritional interventions that reduce oxidation or inflammation in conjunction with higher protein intakes that overcome the anabolic resistance may enhance the MPS response to feeding and either increase muscle mass or attenuate loss. In preliminary studies, antioxidant vitamins and amino acids with antioxidant or anti-inflammatory properties show potential to restore the anabolic response associated with protein ingestion. More research, however, is required to investigate if these nutrients translate to increases in MPS and, ultimately, increased lean mass in aging humans. The purpose of the present review is to discuss the role of protein/EAA intake to enhance postprandial MPS during conditions associated with muscle loss, and bring new perspectives and challenges associated nutritional interventions aimed to optimize the anabolic effects of dietary protein/EAAs ingestion.
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Affiliation(s)
- Jason M Cholewa
- Department of Kinesiology, Coastal Carolina University, Conway, SC, 29528, USA
| | | | - Fernanda Lima-Soares
- Federal University of Maranhão (UFMA), Department of Physical Education, São Luis, Maranhão, Brazil.,Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil
| | - Kassiana de Araújo Pessôa
- Federal University of Maranhão (UFMA), Department of Physical Education, São Luis, Maranhão, Brazil.,Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil
| | - Paulo Henrique Oliveira
- Federal University of Maranhão (UFMA), Department of Physical Education, São Luis, Maranhão, Brazil.,Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil
| | - João Ricardo Dos Santos Pinho
- Federal University of Maranhão (UFMA), Department of Physical Education, São Luis, Maranhão, Brazil.,Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil
| | - Humberto Nicastro
- Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil
| | - Zhi Xia
- Exercise Physiology and Biochemistry Laboratory, College of Physical Education, Jinggangshan University, Ji'an, China.,Department of Sports Medicine, Chengdu Sport Institute, Chengdu, China
| | - Christian Emmanuel Torres Cabido
- Federal University of Maranhão (UFMA), Department of Physical Education, São Luis, Maranhão, Brazil.,Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil
| | - Nelo Eidy Zanchi
- Federal University of Maranhão (UFMA), Department of Physical Education, São Luis, Maranhão, Brazil. .,Laboratory of Cellular and Molecular Biology of Skeletal Muscle (LABCEMME), São Luis, Maranhão, Brazil.
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105
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Miki A, Hashimoto Y, Matsumoto S, Ushigome E, Fukuda T, Sennmaru T, Tanaka M, Yamazaki M, Fukui M. Protein Intake, Especially Vegetable Protein Intake, Is Associated with Higher Skeletal Muscle Mass in Elderly Patients with Type 2 Diabetes. J Diabetes Res 2017; 2017:7985728. [PMID: 29209633 PMCID: PMC5676451 DOI: 10.1155/2017/7985728] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/20/2017] [Accepted: 10/04/2017] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND/AIMS Protein intake is important for maintaining muscle mass in general population. However, it remains to be elucidated the association between dietary protein intake and skeletal muscle mass in elderly patients with type 2 diabetes. METHODS In this cross-sectional study of 168 elderly patients with type 2 diabetes, we investigated the relationship between skeletal muscle index (SMI) and protein intake. Bioimpedance analysis was used for measurement for skeletal muscle mass (kg) and SMI (%), which was defined as skeletal muscle mass (kg)/total body weight (kg) × 100. Habitual food and nutrient intake were estimated by a questionnaire. RESULTS Protein intake was independently correlated with SMI after adjusting for age, hemoglobin A1c, C-peptide index, exercise, smoking, insulin treatment, total energy intake, and C-reactive protein (standardized regression coefficient = 0.664, P < 0.001 in men and standardized regression coefficient = 0.516, P = 0.005 in women). Additionally, the animal protein to vegetable protein ratio was negatively correlated with SMI after adjusting for covariates in men (standardized regression coefficient = -0.339, P = 0.005). CONCLUSIONS We found that total protein intake, especially vegetable protein intake, was positively associated with skeletal muscle mass in elderly patients with type 2 diabetes.
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Affiliation(s)
- Akane Miki
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Yoshitaka Hashimoto
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Shinobu Matsumoto
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Emi Ushigome
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Takuya Fukuda
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Takafumi Sennmaru
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Muhei Tanaka
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Masahiro Yamazaki
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
| | - Michiaki Fukui
- Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, Japan
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106
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Wan J, Chen D, Yu B, Luo Y, Mao X, Zheng P, Yu J, Luo J, He J. Leucine Protects Against Skeletal Muscle Atrophy in Lipopolysaccharide-Challenged Rats. J Med Food 2016; 20:93-101. [PMID: 28009536 DOI: 10.1089/jmf.2016.3759] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Skeletal muscle atrophy is a decrease in muscle mass that occurs when protein degradation exceeds protein synthesis. Leucine (Leu), an essential branched-chain amino acid in animal nutrition, regulates skeletal muscle protein metabolism. Two experiments were conducted to evaluate whether Leu could alleviate lipopolysaccharide (LPS)-induced skeletal muscle wasting by modulating skeletal muscle protein synthesis and degradation. A total of 24 rats were randomly allocated into three groups (n = 8): (1) non-challenged control; (2) LPS-challenged control; and (3) LPS +3.0% Leu. Rats were fed with control or Leu-supplemented (part of the casein was replaced with 3.0% Leu) diets throughout the trial and were injected intraperitoneally with sterile saline or LPS at days 6, 11, 16, and 21. On the morning of day 22, serum samples were collected and rats were then sacrificed for liver and muscle analysis. In vitro protein degradation, nuclear factor-κB (NF-κB) activity, and proteolytic enzyme activities of the muscles from immune-challenged rats were also measured. Our results showed that the LPS challenge resulted in not only enhanced serum interleukin-1 and liver C-reactive protein (CRP) concentrations but also decreased the average daily body weight gain and muscle fiber diameter. However, dietary Leu inclusion attenuated the increase in CRP level and the decrease in muscle fiber diameter. Importantly, the LPS challenge caused a significant elevation in the muscle proteolysis rate, but dietary Leu supplementation significantly blocked the muscle proteolysis. The mRNA expression of NF-κB, muscle atrophy F-box (MAFbx), and muscle ring finger 1 (MuRF1) was upregulated by the LPS challenge in gastrocnemius muscles, but was downregulated by Leu supplementation. Interestingly, when muscles from the LPS-challenged rats were incubated with Leu in vitro, proteasome-, calpain-, and cathepsin-L-dependent muscle proteolysis and NF-κB activity were decreased. Collectively, the data suggest that Leu supplementation could inhibit excessive skeletal muscle degradation, as well as enhance protein synthesis and, thus, attenuate the negative effects caused by the LPS-induced immune challenge.
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Affiliation(s)
- Jin Wan
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Daiwen Chen
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Yuheng Luo
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Xiangbing Mao
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Ping Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Jie Yu
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Junqiu Luo
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
| | - Jun He
- Institute of Animal Nutrition, Sichuan Agricultural University , Chengdu, Wenjiang District, Sichuan, China
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107
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Jiao J, Han SF, Zhang W, Xu JY, Tong X, Yin XB, Yuan LX, Qin LQ. Chronic leucine supplementation improves lipid metabolism in C57BL/6J mice fed with a high-fat/cholesterol diet. Food Nutr Res 2016; 60:31304. [PMID: 27616737 PMCID: PMC5018683 DOI: 10.3402/fnr.v60.31304] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 12/20/2022] Open
Abstract
Background Leucine supplementation has been reported to improve lipid metabolism. However, lipid metabolism in adipose tissues and liver has not been extensively studied for leucine supplementation in mice fed with a high-fat/cholesterol diet (HFCD). Design C57BL/6J mice were fed a chow diet, HFCD, HFCD supplemented with 1.5% leucine (HFCD+1.5% Leu group) or 3% leucine (HFCD+3% Leu group) for 24 weeks. The body weight, peritoneal adipose weight, total cholesterol (TC), triglyceride in serum and liver, and serum adipokines were analyzed. In addition, expression levels of proteins associated with hepatic lipogenesis, adipocyte lipolysis, and white adipose tissue (WAT) browning were determined. Results Mice in the HFCD group developed obesity and deteriorated lipid metabolism. Compared with HFCD, leucine supplementation lowered weight gain and TC levels in circulation and the liver without changing energy intake. The decrease in body fat was supported by histological examination in the WAT and liver. Furthermore, serum levels of proinflammatory adipokines, such as leptin, IL-6, and tumor necrosis factor-alpha, were significantly decreased by supplemented leucine. At the protein level, leucine potently decreased the hepatic lipogenic enzymes (fatty acid synthase and acetyl-coenzyme A carboxylase) and corresponding upstream proteins. In epididymal WAT, the reduced expression levels of two major lipases by HFCD, namely phosphorylated hormone-sensitive lipase and adipose triglyceride lipase, were reversed when leucine was supplemented. Uncoupling protein 1, β3 adrenergic receptors, peroxisome proliferator-activated receptor g coactivator-1α, and fibroblast growth factor 21 were involved in the thermogenic program and WAT browning. Leucine additionally upregulated their protein expression in both WAT and interscapular brown adipose tissue. Conclusion This study demonstrated that chronic leucine supplementation reduced the body weight and improved the lipid profile of mice fed with a HFCD. This beneficial effect was ascribed to hepatic lipogenesis, adipocyte lipolysis, and WAT browning.
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Affiliation(s)
- Jun Jiao
- Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China
| | - Shu-Fen Han
- Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China
| | - Wei Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China
| | - Jia-Ying Xu
- School of Radiation Medicine and Protection, Soochow University, Suzhou, China.,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou, China
| | - Xing Tong
- Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China
| | - Xue-Bin Yin
- Jiangsu Bio-Engineering Research Centre of Selenium, Suzhou, China
| | - Lin-Xi Yuan
- Jiangsu Bio-Engineering Research Centre of Selenium, Suzhou, China
| | - Li-Qiang Qin
- Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China.,Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Disease, Soochow University, Suzhou, China;
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108
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Galvan E, Arentson-Lantz E, Lamon S, Paddon-Jones D. Protecting Skeletal Muscle with Protein and Amino Acid during Periods of Disuse. Nutrients 2016; 8:E404. [PMID: 27376322 PMCID: PMC4963880 DOI: 10.3390/nu8070404] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 06/16/2016] [Accepted: 06/23/2016] [Indexed: 12/18/2022] Open
Abstract
Habitual sedentary behavior increases risk of chronic disease, hospitalization and poor quality of life. Short-term bed rest or disuse accelerates the loss of muscle mass, function, and glucose tolerance. Optimizing nutritional practices and protein intake may reduce the consequences of disuse by preserving metabolic homeostasis and muscle mass and function. Most modes of physical inactivity have the potential to negatively impact the health of older adults more than their younger counterparts. Mechanistically, mammalian target of rapamycin complex 1 (mTORC1) signaling and muscle protein synthesis are negatively affected by disuse. This contributes to reduced muscle quality and is accompanied by impaired glucose regulation. Simply encouraging increased protein and/or energy consumption is a well-intentioned, but often impractical strategy to protect muscle health. Emerging evidence suggests that leucine supplemented meals may partially and temporarily protect skeletal muscle during disuse by preserving anabolism and mitigating reductions in mass, function and metabolic homeostasis.
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Affiliation(s)
- Elfego Galvan
- Center for Rehabilitation and Physical Activity and Nutrition (CeRPAN), University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Emily Arentson-Lantz
- Center for Rehabilitation and Physical Activity and Nutrition (CeRPAN), University of Texas Medical Branch, Galveston, TX 77555, USA.
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Séverine Lamon
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong 3125, Australia.
| | - Douglas Paddon-Jones
- Center for Rehabilitation and Physical Activity and Nutrition (CeRPAN), University of Texas Medical Branch, Galveston, TX 77555, USA.
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, TX 77555, USA.
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109
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Identifying effective and feasible interventions to accelerate functional recovery from hospitalization in older adults: A randomized controlled pilot trial. Contemp Clin Trials 2016; 49:6-14. [PMID: 27178766 DOI: 10.1016/j.cct.2016.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 04/25/2016] [Accepted: 05/09/2016] [Indexed: 01/08/2023]
Abstract
Hospitalization induces functional decline in older adults. Many geriatric patients fail to fully recover physical function after hospitalization, which increases the risk of frailty, disability, dependence, re-hospitalization, and mortality. There is a lack of evidence-based therapies that can be implemented following hospitalization to accelerate functional improvements. The aims of this Phase I clinical trial are to determine 1) the effect size and variability of targeted interventions in accelerating functional recovery from hospitalization and 2) the feasibility of implementing such interventions in community-dwelling older adults. Older patients (≥65years, n=100) will be recruited from a single site during hospitalization for an acute medical condition. Subjects will be randomized to one of five interventions initiated immediately upon discharge: 1. protein supplementation, 2. in-home rehabilitation plus placebo supplementation, 3. in-home rehabilitation plus protein supplementation, 4. single testosterone injection, or 5. isocaloric placebo supplementation. Testing will occur during hospitalization (baseline) and at 1 and 4weeks post-discharge. Each testing session will include measures of muscle strength, physical function/performance, body composition, and psychological function. Physical activity levels will be continuously monitored throughout study participation. Feasibility will be determined through collection of the number of eligible, contacted, and enrolled patients; intervention adherence and compliance; and reasons for declining enrollment and study withdrawal. This research will determine the feasibility of post-hospitalization strategies to improve physical function in older adults. These results will also provide a foundation for performing larger, multi-site clinical trials to improve physical function and reduce readmissions in geriatric patents.
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110
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Arentson-Lantz EJ, English KL, Paddon-Jones D, Fry CS. Fourteen days of bed rest induces a decline in satellite cell content and robust atrophy of skeletal muscle fibers in middle-aged adults. J Appl Physiol (1985) 2016; 120:965-75. [PMID: 26796754 DOI: 10.1152/japplphysiol.00799.2015] [Citation(s) in RCA: 124] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 01/20/2016] [Indexed: 01/06/2023] Open
Abstract
Bed rest, a ground-based spaceflight analog, induces robust atrophy of skeletal muscle, an effect that is exacerbated with increasing age. We examined the effect of 14 days of bed rest on skeletal muscle satellite cell content and fiber type atrophy in middle-aged adults, an understudied age demographic with few overt signs of muscle aging that is representative of astronauts who perform long-duration spaceflight. Muscle biopsies were obtained from the vastus lateralis of healthy middle-aged adults [n= 7 (4 male, 3 female); age: 51 ± 1 yr] before (Pre-BR) and after (Post-BR) 14 days of bed rest. Immunohistochemical analyses were used to quantify myosin heavy chain (MyHC) isoform expression, cross-sectional area (CSA), satellite cell and myonuclear content, and capillary density. Peak oxygen consumption, knee extensor strength, and body composition were also measured Pre-BR and Post-BR. Post-BR MyHC type 2a fiber percentage was reduced, and mean CSA decreased in all fiber types (-24 ± 5%;P< 0.05). Satellite cell content was also reduced Post-BR (-39 ± 9%;P< 0.05), and the change in satellite cell content was significantly correlated with the change in mean fiber CSA (r(2)= 0.60;P< 0.05). A decline in capillary density was observed Post-BR (-23 ± 6%;P< 0.05), and Post-BR capillary content was significantly associated with Post-BR peak aerobic capacity (r(2)= 0.59;P< 0.05). A subtle decline in myonuclear content occurred during bed rest (-5 ± 1%;P< 0.05). The rapid maladaptation of skeletal muscle to 14 days of mechanical unloading in middle-aged adults emphasizes the need for robust countermeasures to preserve muscle function in astronauts.
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Affiliation(s)
- Emily J Arentson-Lantz
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas; Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas
| | - Kirk L English
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas; Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas
| | - Douglas Paddon-Jones
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas; Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas
| | - Christopher S Fry
- Department of Nutrition and Metabolism, University of Texas Medical Branch, Galveston, Texas; Division of Rehabilitation Sciences, University of Texas Medical Branch, Galveston, Texas; Sealy Center on Aging, University of Texas Medical Branch, Galveston, Texas
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