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Effect of electromyostimulation training on intramuscular fat accumulation determined by ultrasonography in older adults. Eur J Appl Physiol 2023; 123:271-282. [PMID: 36260185 PMCID: PMC9580431 DOI: 10.1007/s00421-022-05074-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 10/11/2022] [Indexed: 02/07/2023]
Abstract
PURPOSE Electromyostimulation (EMS) induces a short-term change in muscle metabolism, and EMS training induces long-term improvements of muscle atrophy and function. However, the effects of EMS training on intramuscular fat in older adults are still poorly known. The purpose of this study was to examine whether the intramuscular fat index and biochemical parameters change with EMS training of the quadriceps femoris muscles in older adults. METHODS Nineteen non-obese older men and women performed EMS training of the quadriceps femoris for 12 weeks (3 times/week; single session for 30 min). The intramuscular fat content index was estimated by echo intensity of the vastus lateralis and rectus femoris muscles on ultrasonography, and muscle thickness was also measured. Muscle strength was assessed as the maximal voluntary contraction during isometric knee extension. Echo intensity, muscle thickness, and muscle strength were measured before and after EMS training. A rested/fasting blood samples were collected before and after EMS training for measuring plasma glucose, insulin, free fatty acid, triglyceride, and interleukin-6 concentrations. To examine the acute effect of a single-EMS session on biochemical parameters, blood samples were taken before and after the EMS session. RESULTS EMS training did not significantly change echo intensity in muscles, muscle thickness, muscle strength, or biochemical parameters. Regarding the acute effect on blood lipid concentrations, a single-EMS session increased free fatty acid and glucose concentrations. CONCLUSION EMS sessions had an acute effect of increasing free fatty acid and glucose concentrations, but EMS training intervention did not improve intramuscular fat content.
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Hioki M, Kanehira N, Koike T, Saito A, Takahashi H, Shimaoka K, Sakakibara H, Oshida Y, Akima H. Effect of electromyostimulation on intramyocellular lipids of the vastus lateralis in older adults: a randomized controlled trial. BMC Musculoskelet Disord 2021; 22:569. [PMID: 34158031 PMCID: PMC8218407 DOI: 10.1186/s12891-021-04456-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 05/26/2021] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Excessive intramyocellular lipid (IMCL) accumulation is a primary cause of skeletal muscle insulin resistance, especially in older adults, and interventions that reduce IMCL contents are important to improve insulin sensitivity. Electromyostimulation (EMS)-induced changes in IMCL content in older adults remain unknown. The purpose of this study was to clarify the effects of a single bout of EMS on the IMCL content of the vastus lateralis muscle in older adults. METHODS Twenty-two physically active, non-obese older men and women were randomly assigned to an EMS intervention group (69.0 ± 5.2 years, n = 12) or a control group (68.4 ± 3.5 years, n = 10). EMS was applied to the vastus lateralis (7 s on and 7 s off) for 30 min; control participants sat quietly for 30 min. IMCL content within the vastus lateralis was quantified with 1H-magnetic resonance spectroscopy (n = 7 per group). Fasting plasma glucose and insulin values were determined from blood samples collected before and after the EMS intervention. RESULTS EMS induced a significant reduction in plasma glucose (93.1 ± 9.6 to 89.5 ± 9.1 mg/dL, p < 0.01), but not IMCL content (15.7 ± 15.7 to 15.8 ± 13.1 mmol/kg wet weight, p = 0.49) or insulin (5.4 ± 2.4 to 4.7 ± 2.7 μIU/mL, p = 0.18). In the control group, no changes in IMCL content in the vastus lateralis was observed after prolonged quiet sitting. CONCLUSION EMS intervention for 30 min induces changes in plasma glucose, but no changes in IMCL content in older adults. TRIAL REGISTRATION University hospital Medical Information Network (UMIN) Center ID: UMIN000020126 . Retrospectively registered on December 222,015. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000023242.
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Affiliation(s)
- Maya Hioki
- Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa-ku, Nagoya, Aichi, 466-8550, Japan.
| | - Nana Kanehira
- Department of Health and Nutrition, Tokaigakuen University, 2-901 Nakahira, Tenpaku, Nagoya, Aichi, 468-8514, Japan
| | - Teruhiko Koike
- Research Center of Health, Physical Fitness & Sports, Nagoya University, 1 Furo, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Akira Saito
- Center for Health and Sports Science, Kyushu Sangyo University, 2-3-1 Matsukadai, Higashi-ku, Fukuoka, Fukuoka, 813-8503, Japan
| | - Hideyuki Takahashi
- Japan Institute of Sports Sciences, 3-15-1 Nishigaoka, Kita-ku, Tokyo, 115-0056, Japan
| | - Kiyoshi Shimaoka
- Department of Human Wellness, Tokaigakuen University, 21-233 Nishinohora, Ukigai, Miyoshi, Aichi, 470-0207, Japan
| | - Hisataka Sakakibara
- Ichinomiya Kenshin College of Nursing, 5-4-1 Jouganndoori, Ichinomiya, Aichi, 491-0063, Japan
| | - Yoshiharu Oshida
- Research Center of Health, Physical Fitness & Sports, Nagoya University, 1 Furo, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Hiroshi Akima
- Research Center of Health, Physical Fitness & Sports, Nagoya University, 1 Furo, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
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Chee C, Shannon CE, Burns A, Selby AL, Wilkinson D, Smith K, Greenhaff PL, Stephens FB. Increasing skeletal muscle carnitine content in older individuals increases whole-body fat oxidation during moderate-intensity exercise. Aging Cell 2021; 20:e13303. [PMID: 33464721 PMCID: PMC7884033 DOI: 10.1111/acel.13303] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 11/20/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022] Open
Abstract
Intramyocellular lipid (IMCL) utilization is impaired in older individuals, and IMCL accumulation is associated with insulin resistance. We hypothesized that increasing muscle total carnitine content in older men would increase fat oxidation and IMCL utilization during exercise, and improve insulin sensitivity. Fourteen healthy older men (69 ± 1 year, BMI 26.5 ± 0.8 kg/m2 ) performed 1 h of cycling at 50% VO2 max and, on a separate occasion, underwent a 60 mU/m2 /min euglycaemic hyperinsulinaemic clamp before and after 25 weeks of daily ingestion of a 220 ml insulinogenic beverage (44.4 g carbohydrate, 13.8 g protein) containing 4.5 g placebo (n = 7) or L-carnitine L-tartrate (n = 7). During supplementation, participants performed twice-weekly cycling for 1 h at 50% VO2 max. Placebo ingestion had no effect on muscle carnitine content or total fat oxidation during exercise at 50% VO2 max. L-carnitine supplementation resulted in a 20% increase in muscle total carnitine content (20.1 ± 1.2 to 23.9 ± 1.7 mmol/kg/dm; p < 0.01) and a 20% increase in total fat oxidation (181.1 ± 15.0 to 220.4 ± 19.6 J/kg lbm/min; p < 0.01), predominantly due to increased IMCL utilization. These changes were associated with increased expression of genes involved in fat metabolism (ACAT1, DGKD & PLIN2; p < 0.05). There was no change in resting insulin-stimulated whole-body or skeletal muscle glucose disposal after supplementation. This is the first study to demonstrate that a carnitine-mediated increase in fat oxidation is achievable in older individuals. This warrants further investigation given reduced lipid turnover is associated with poor metabolic health in older adults.
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Affiliation(s)
- Carolyn Chee
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing ResearchSchool of Life SciencesUniversity of NottinghamNottinghamUK
| | - Chris E. Shannon
- Diabetes DivisionUniversity of Texas Health Science CentreSan AntonioTXUSA
| | - Aisling Burns
- Sam and Ann Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science CentreSan AntonioTXUSA
| | - Anna L. Selby
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing ResearchSchool of MedicineUniversity of NottinghamNottinghamUK
| | - Daniel Wilkinson
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing ResearchSchool of MedicineUniversity of NottinghamNottinghamUK
| | - Kenneth Smith
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing ResearchSchool of MedicineUniversity of NottinghamNottinghamUK
| | - Paul L. Greenhaff
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing ResearchSchool of Life SciencesUniversity of NottinghamNottinghamUK
| | - Francis B. Stephens
- Department of Sport and Health SciencesSt Luke's CampusUniversity of ExeterExeterUK
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Seibert JT, Najt CP, Heden TD, Mashek DG, Chow LS. Muscle Lipid Droplets: Cellular Signaling to Exercise Physiology and Beyond. Trends Endocrinol Metab 2020; 31:928-938. [PMID: 32917515 PMCID: PMC7704552 DOI: 10.1016/j.tem.2020.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 07/09/2020] [Accepted: 08/13/2020] [Indexed: 12/21/2022]
Abstract
Conventionally viewed as energy storage depots, lipid droplets (LDs) play a central role in muscle lipid metabolism and intracellular signaling, as recognized by recent advances in our biological understanding. Specific subpopulations of muscle LDs, defined by location and associated proteins, are responsible for distinct biological functions. In this review, the traditional view of muscle LDs is examined, and the emerging role of LDs in intracellular signaling is highlighted. The effects of chronic and acute exercise on muscle LD metabolism and signaling is discussed. In conclusion, future directions for muscle LD research are identified. The primary focus will be on human studies, with inclusion of select animal/cellular/non-muscle studies as appropriate, to provide the underlying mechanisms driving the observed findings.
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Affiliation(s)
- Jacob T Seibert
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Charles P Najt
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Timothy D Heden
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Douglas G Mashek
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, MN 55455, USA
| | - Lisa S Chow
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, University of Minnesota, Minneapolis, MN 55455, USA.
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Marzuca-Nassr GN, SanMartín-Calísto Y, Guerra-Vega P, Artigas-Arias M, Alegría A, Curi R. Skeletal Muscle Aging Atrophy: Assessment and Exercise-Based Treatment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1260:123-158. [PMID: 32304033 DOI: 10.1007/978-3-030-42667-5_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In the ordinary course of aging, individuals change their body composition, mainly reducing their skeletal muscle mass and increasing their fat mass. In association, muscle strength and functionality also decrease. The geriatric assessment allows knowing the baseline situation of the patients, determines the impact of diseases, and defines specific treatments. There are various tools to evaluate the health condition of older people. These tools include the assessment scales of necessary Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL), physical and functional assessment scales, and instruments that assess the cognitive state of the person. There are several strategies that have been proposed to combat skeletal muscle atrophy due to aging, such as physical exercise, nutritional supplements, or drugs. Some researchers have highlighted the efficacy of the combination of the mentioned strategies. In this chapter, we will focus only on physical exercise as a strategy to reduce skeletal muscle loss during aging.
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Affiliation(s)
- Gabriel Nasri Marzuca-Nassr
- Departamento de Medicina Interna, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile. .,Magíster en Terapia Física con menciones, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile.
| | - Yuri SanMartín-Calísto
- Magíster en Terapia Física con menciones, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile
| | - Pablo Guerra-Vega
- Magíster en Terapia Física con menciones, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile.,Escuela de Kinesiología, Facultad de Ciencias de la Salud, Universidad San Sebastián, Puerto Montt, Chile
| | - Macarena Artigas-Arias
- Magíster en Terapia Física con menciones, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile
| | - Andrea Alegría
- Magíster en Terapia Física con menciones, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile
| | - Rui Curi
- Interdisciplinary Post-Graduate Program in Health Sciences, Cruzeiro do Sul University, Sao Paulo, Brazil
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Tsintzas K, Jones R, Pabla P, Mallinson J, Barrett DA, Kim DH, Cooper S, Davies A, Taylor T, Chee C, Gaffney C, van Loon LJC, Stephens FB. Effect of acute and short-term dietary fat ingestion on postprandial skeletal muscle protein synthesis rates in middle-aged, overweight, and obese men. Am J Physiol Endocrinol Metab 2020; 318:E417-E429. [PMID: 31910028 DOI: 10.1152/ajpendo.00344.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Muscle anabolic resistance to dietary protein is associated with obesity and insulin resistance. However, the contribution of excess consumption of fat to anabolic resistance is not well studied. The aim of these studies was to test the hypothesis that acute and short-term dietary fat overload will impair the skeletal muscle protein synthetic response to dietary protein ingestion. Eight overweight/obese men [46.4 ± 1.4 yr, body mass index (BMI) 32.3 ± 5.4 kg/m2] participated in the acute feeding study, which consisted of two randomized crossover trials. On each occasion, subjects ingested an oral meal (with and without fat emulsion), 4 h before the coingestion of milk protein, intrinsically labeled with [1-13C]phenylalanine, and dextrose. Nine overweight/obese men (44.0 ± 1.7 yr, BMI 30.1 ± 1.1 kg/m2) participated in the chronic study, which consisted of a baseline, 1-wk isocaloric diet, followed by a 2-wk high-fat diet (+25% energy excess). Acutely, incorporation of dietary amino acids into the skeletal muscle was twofold higher (P < 0.05) in the lipid trial compared with control. There was no effect of prior lipid ingestion on indices of insulin sensitivity (muscle glucose uptake, pyruvate dehydrogenase complex activity, and Akt phosphorylation) in response to the protein/dextrose drink. Fat overfeeding had no effect on muscle protein synthesis or glucose disposal in response to whey protein ingestion, despite increased muscle diacylglycerol C16:0 (P = 0.06) and ceramide C16:0 (P < 0.01) levels. Neither acute nor short-term dietary fat overload has a detrimental effect on the skeletal muscle protein synthetic response to dietary protein ingestion in overweight/obese men, suggesting that dietary-induced accumulation of intramuscular lipids per se is not associated with anabolic resistance.
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Affiliation(s)
- Kostas Tsintzas
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Robert Jones
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Pardeep Pabla
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Joanne Mallinson
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - David A Barrett
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
| | - Dong-Hyun Kim
- Centre for Analytical Bioscience, Advanced Materials and Healthcare Technologies Division, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
| | - Scott Cooper
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Amanda Davies
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Tariq Taylor
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Carolyn Chee
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Christopher Gaffney
- MRC/Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, United Kingdom
| | - Luc J C van Loon
- Department of Human Movement Sciences, Maastricht University, Maastricht, The Netherlands
| | - Francis B Stephens
- School of Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
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Lavin KM, Perkins RK, Jemiolo B, Raue U, Trappe SW, Trappe TA. Effects of aging and lifelong aerobic exercise on basal and exercise-induced inflammation. J Appl Physiol (1985) 2020; 128:87-99. [PMID: 31751180 PMCID: PMC6985808 DOI: 10.1152/japplphysiol.00495.2019] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/07/2019] [Accepted: 11/07/2019] [Indexed: 12/20/2022] Open
Abstract
Age-associated chronic basal inflammation compromises muscle mass and adaptability, but exercise training may exert an anti-inflammatory effect. This investigation assessed basal and exercise-induced inflammation in three cohorts of men: young exercisers [YE; n = 10 men; 25 ± 1 yr; maximal oxygen consumption (V̇o2max), 53 ± 3 mL·kg-1·min-1; quadriceps area, 78 ± 3 cm2; means ± SE], old healthy nonexercisers (OH; n = 10; 75 ± 1 yr; V̇o2max, 22 ± 1 mL·kg-1·min-1; quadriceps area, 56 ± 3 cm2), and lifelong exercisers with an aerobic training history of 53 ± 1 yr (LLE; n = 21; 74 ± 1 yr; V̇o2max, 34 ± 1 mL·kg-1·min-1; quadriceps area, 67 ± 2 cm2). Resting serum IL-6, TNF-α, C-reactive protein, and IGF-1 levels were measured. Vastus lateralis muscle biopsies were obtained at rest (basal) and 4 h after an acute exercise challenge (3 × 10 repetitions, 70% 1-repetition maximum) to assess gene expression of cytokines [IL-6, TNF-α, IL-1β, IL-10, IL-4, interleukin-1 receptor antagonist (IL-1Ra), and transforming growth factor-β (TGF-β)], chemokines [IL-8 and monocyte chemoattractant protein-1 (MCP-1)], cyclooxygenase enzymes [cyclooxygenase-1 and -2 (COX-1 and COX-2, respectively), prostaglandin E2 synthases [microsomal prostaglandin E synthase 1 (mPGES-1) and cytosolic prostaglandin E2 synthase (cPGES)] and receptors [prostaglandin E2 receptor EP3 and EP4 subtypes (EP3 and EP4, respectively), and macrophage markers [cluster of differentiation 16b (CD16b) and CD163], as well as basal macrophage abundance (CD68+ cells). Aging led to higher (P ≤ 0.05) circulating IL-6 and skeletal muscle COX-1, mPGES-1, and CD163 expression. However, LLE had significantly lower serum IL-6 levels (P ≤ 0.05 vs. OH) and a predominantly anti-inflammatory muscle profile [higher IL-10 (P ≤ 0.05 vs. YE), TNF-α, TGF-β, and EP4 levels (P ≤ 0.05 vs. OH)]. In OH only, acute exercise increased expression of proinflammatory factors TNF-α, TGF-β, and IL-8 (P ≤ 0.05). LLE had postexercise gene expression similar to YE, except lower IL-10 (P ≤ 0.10), mPGES-1, and EP3 expression (P ≤ 0.05). Thus, although aging led to a proinflammatory profile within blood and muscle, lifelong exercise partially prevented this and generally preserved the acute inflammatory response to exercise seen in young exercising men. Lifelong exercise may positively impact muscle health throughout aging by promoting anti-inflammation in skeletal muscle.NEW & NOTEWORTHY This study assessed a unique population of lifelong aerobic exercising men and demonstrated that their activity status exerts an anti-inflammatory effect in skeletal muscle and circulation. Furthermore, we provide evidence that the inflammatory response to acute exercise is dysregulated by aging but preserved with lifelong exercise, which might improve skeletal muscle resilience to unaccustomed loading and adaptability into late life.
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Affiliation(s)
- Kaleen M Lavin
- Human Performance Laboratory, Ball State University, Muncie, Indiana
| | - Ryan K Perkins
- Human Performance Laboratory, Ball State University, Muncie, Indiana
| | - Bozena Jemiolo
- Human Performance Laboratory, Ball State University, Muncie, Indiana
| | - Ulrika Raue
- Human Performance Laboratory, Ball State University, Muncie, Indiana
| | - Scott W Trappe
- Human Performance Laboratory, Ball State University, Muncie, Indiana
| | - Todd A Trappe
- Human Performance Laboratory, Ball State University, Muncie, Indiana
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Shah M, Bailey S, Gloeckner A, Kreutzer A, Adams-Huet B, Cheek D, Mitchell J. Effect of acute exercise on postprandial endothelial function in postmenopausal women: a randomized cross-over study. J Investig Med 2019; 67:964-970. [PMID: 30842213 DOI: 10.1136/jim-2019-000992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2019] [Indexed: 11/03/2022]
Abstract
High-sugar intake may cause endothelial dysfunction. It is unknown if a bout of aerobic exercise improves endothelial dysfunction caused by a high-sugar meal in postmenopausal women. This study evaluated if prior aerobic exercise attenuates postprandial endothelial dysfunction in postmenopausal women. Twenty-two postmenopausal women (age [mean±SD]: 60.4±6.5 years; % body fat: 40.3%±7.5%) underwent an exercise (EX) or no exercise (NE) condition, in a random order, 13-16 hours prior to the high-sugar meal consumption. The EX condition included a 60 min bout of supervised aerobic exercise at 75% of age-predicted maximum heart rate. The high-sugar meal, consumed after a 12-hour fast, contained 33% of the subjects' daily energy needs, and 75.6% energy from carbohydrates. Flow-mediated dilation (FMD) and blood concentrations of glucose, insulin, endothelin-1 (ET-1), and nitric oxide (NO) were assessed at baseline and 60 min, 120 min, and 180 min postprandially. Repeated measures analysis test showed that there were no condition by time interaction or condition effects for FMD, glucose, insulin, or NO. There was a significant condition by time interaction but no condition effect for ET-1. Area under the curve was also not different by condition for insulin sensitivity or the above variables. In conclusion, prior aerobic exercise compared with NE did not affect FMD, blood glucose, insulin, ET-1 or NO concentrations, or insulin sensitivity following a high-sugar meal in postmenopausal women. Future studies should look at the effect of different EX intensities on meal-induced endothelial dysfunction in this population. Trial Registration: ClinicalTrials.gov Identifier: NCT02919488.
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Affiliation(s)
- Meena Shah
- Kinesiology, Texas Christian University, Fort Worth, Texas, USA
| | - Sarah Bailey
- Kinesiology, Texas Christian University, Fort Worth, Texas, USA
| | - Adam Gloeckner
- Kinesiology, Texas Christian University, Fort Worth, Texas, USA
| | | | | | - Dennis Cheek
- Nursing, Texas Christian University, Fort Worth, Texas, USA
| | - Joel Mitchell
- Kinesiology, Texas Christian University, Fort Worth, Texas, USA
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Poleti MD, Moncau CT, Silva-Vignato B, Rosa AF, Lobo AR, Cataldi TR, Negrão JA, Silva SL, Eler JP, de Carvalho Balieiro JC. Label-free quantitative proteomic analysis reveals muscle contraction and metabolism proteins linked to ultimate pH in bovine skeletal muscle. Meat Sci 2018; 145:209-219. [DOI: 10.1016/j.meatsci.2018.06.041] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 12/23/2022]
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10
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Relationship between physical activity and intramyocellular lipid content is different between young and older adults. Eur J Appl Physiol 2018; 119:113-122. [PMID: 30306258 DOI: 10.1007/s00421-018-4005-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 10/01/2018] [Indexed: 02/06/2023]
Abstract
PURPOSE Intramyocellular lipid (IMCL) is influenced by physical exercise; however, whether the habitual level of physical activity affects resting IMCL content remains unclear. The purpose of this study was to determine the relationship between physical activity levels and resting IMCL content in young and older adults. METHODS In total, 15 nonobese young adults (21.0 ± 0.0 years) and 15 older adults (70.7 ± 3.8 years) were recruited. Time spent performing physical activities for 10 days was assessed using a three-dimensional ambulatory accelerometer, and intensity was categorized as light [< 3.0 metabolic equivalents (METs)], moderate (3.0-6.0 METs), or vigorous (> 6.0 METs). Physical activity level was calculated as the product of METs and time spent performing physical activities (MET h) at each intensity level. The IMCL content in the vastus lateralis was determined using 1H-magnetic resonance spectroscopy after overnight fasting. RESULTS No significant differences in IMCL content were observed between young and older adults. Vigorous intensity physical activity (time and MET h) was significantly lower in older than young adults (p < 0.01); this difference was not observed for light and moderate intensity physical activity. Light intensity physical activity (time and MET h) was significantly and inversely correlated with IMCL content in young adults (r = - 0.59 and r = - 0.58; both p < 0.05), but not in older adults. CONCLUSIONS These results suggest that daily light intensity physical activity reduces resting IMCL content in young adults, whereas no significant relationship was seen between daily physical activity and resting IMCL content in older adults.
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11
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Gonzalez JT, Richardson JD, Chowdhury EA, Koumanov F, Holman GD, Cooper S, Thompson D, Tsintzas K, Betts JA. Molecular adaptations of adipose tissue to 6 weeks of morning fasting vs. daily breakfast consumption in lean and obese adults. J Physiol 2018; 596:609-622. [PMID: 29193093 PMCID: PMC5813615 DOI: 10.1113/jp275113] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/13/2017] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS In lean individuals, 6 weeks of extended morning fasting increases the expression of genes involved in lipid turnover (ACADM) and insulin signalling (IRS2) in subcutaneous abdominal adipose tissue. In obese individuals, 6 weeks of extended morning fasting increases IRS2 expression in subcutaneous abdominal adipose tissue. The content and activation status of key proteins involved in insulin signalling and glucose transport (GLUT4, Akt1 and Akt2) were unaffected by extended morning fasting. Therefore, any observations of altered adipose tissue insulin sensitivity with extended morning fasting do not necessarily require changes in insulin signalling proximal to Akt. Insulin-stimulated adipose tissue glucose uptake rates are lower in obese versus lean individuals, but this difference is abolished when values are normalised to whole-body fat mass. This suggests a novel hypothesis which proposes that the reduced adipose glucose uptake in obesity is a physiological down-regulation to prevent excessive de novo lipogenesis. ABSTRACT This study assessed molecular responses of human subcutaneous abdominal adipose tissue (SCAT) to 6 weeks of morning fasting. Forty-nine healthy lean (n = 29) and obese (n = 20) adults provided SCAT biopsies before and after 6 weeks of morning fasting (FAST; 0 kcal until 12.00 h) or daily breakfast consumption (BFAST; ≥700 kcal before 11.00 h). Biopsies were analysed for mRNA levels of selected genes, and GLUT4 and Akt protein content. Basal and insulin-stimulated Akt activation and tissue glucose uptake rates were also determined. In lean individuals, lipid turnover and insulin signalling genes (ACADM and IRS2) were up-regulated with FAST versus BFAST (ACADM: 1.14 (95% CI: 0.97-1.30) versus 0.80 (95% CI: 0.64-0.96), P = 0.007; IRS2: 1.75 (95% CI: 1.33-2.16) versus 1.09 (95% CI: 0.67-1.51), P = 0.03, respectively). In obese individuals, no differential (FAST versus BFAST) expression was observed in genes involved in lipid turnover (all P > 0.1). GLUT4, Akt protein content and insulin-stimulated Akt phosphorylation were unaffected by FAST versus BFAST in both lean and obese cohorts (all P > 0.1). Lower insulin-stimulated glucose uptake rates in obese versus lean individuals were eradicated when normalised to whole-body fat mass (P = 0.416). We conclude that morning fasting up-regulates lipid turnover genes in SCAT of lean individuals. Secondly, altered SCAT insulin sensitivity with morning fasting is unlikely to be explained by signalling proximal to Akt. Finally, lower insulin-stimulated SCAT glucose uptake rates in obese individuals are proportional to whole-body fat mass, suggesting a compensatory down-regulation, presumably to prevent excessive de novo lipogenesis in adipose tissue. This trial was registered as ISRCTN31521726.
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Affiliation(s)
| | | | | | - Francoise Koumanov
- Department for HealthUniversity of BathBathBA2 7AYUK
- Department of Biology & BiochemistryUniversity of BathBathBA2 7AYUK
| | | | - Scott Cooper
- School of Life SciencesQueen's Medical CentreNottinghamNG7 2UHUK
| | | | - Kostas Tsintzas
- School of Life SciencesQueen's Medical CentreNottinghamNG7 2UHUK
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Metabolic and molecular changes associated with the increased skeletal muscle insulin action 24-48 h after exercise in young and old humans. Biochem Soc Trans 2018; 46:111-118. [PMID: 29330356 DOI: 10.1042/bst20170198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 12/25/2022]
Abstract
The molecular and metabolic mechanisms underlying the increase in insulin sensitivity (i.e. increased insulin-stimulated skeletal muscle glucose uptake, phosphorylation and storage as glycogen) observed from 12 to 48 h following a single bout of exercise in humans remain unresolved. Moreover, whether these mechanisms differ with age is unclear. It is well established that a single bout of exercise increases the translocation of the glucose transporter, GLUT4, to the plasma membrane. Previous research using unilateral limb muscle contraction models in combination with hyperinsulinaemia has demonstrated that the increase in insulin sensitivity and glycogen synthesis 24 h after exercise is also associated with an increase in hexokinase II (HKII) mRNA and protein content, suggesting an increase in the capacity of the muscle to phosphorylate glucose and divert it towards glycogen synthesis. Interestingly, this response is altered in older individuals for up to 48 h post exercise and is associated with molecular changes in skeletal muscle tissue that are indicative of reduced lipid oxidation, increased lipogenesis, increased inflammation and a relative inflexibility of changes in intramyocellular lipid (IMCL) content. Reduced insulin sensitivity (insulin resistance) is generally related to IMCL content, particularly in the subsarcolemmal (SSL) region, and both are associated with increasing age. Recent research has demonstrated that ageing per se appears to cause an exacerbated lipolytic response to exercise that may result in SSL IMCL accumulation. Further research is required to determine if increased IMCL content affects HKII expression in the days after exercise in older individuals, and the effect of this on skeletal muscle insulin action.
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