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Ireland A, Mittag U, Degens H, Felsenberg D, Heinonen A, Koltai E, Korhonen MT, McPhee JS, Mekjavic I, Pisot R, Rawer R, Radak Z, Simunic B, Suominen H, Rittweger J. Age-Related Declines in Lower Limb Muscle Function are Similar in Power and Endurance Athletes of Both Sexes: A Longitudinal Study of Master Athletes. Calcif Tissue Int 2022; 110:196-203. [PMID: 34505170 PMCID: PMC8784358 DOI: 10.1007/s00223-021-00907-3] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/18/2021] [Indexed: 11/28/2022]
Abstract
The age-related decline in muscle function, particularly muscle power, is associated with increased risk of important clinical outcomes. Physical activity is an important determinant of muscle function, and different types of physical activity e.g. power-based versus endurance-based exercise appear to have differential effects on muscle power. Cross-sectional studies suggest that participation in power-based exercise is associated with greater muscle power across adulthood but this has not been investigated longitudinally. We recruited eighty-nine male and female power and endurance master athletes (sprint and distance runners respectively, baseline age 35-90y). Using jumping mechanography, we measured lower limb muscle function during a vertical jump including at least two testing sessions longitudinally over 4.5 ± 2.4y. We examined effects of time, discipline (power/endurance) and sex in addition to two- and three-way interactions using linear mixed-effects models. Peak relative power, relative force and jump height, but not Esslingen Fitness Index (indicating peak power relative to sex and age-matched reference data) declined with time. Peak power, force, height and EFI were greater in power than endurance athletes. There were no sex, discipline or sex*discipline interactions with time for any variable, suggesting that changes were similar over time for athletes of both sexes and disciplines. Advantages in lower limb muscle function in power athletes were maintained with time, in line with previous cross-sectional studies. These results suggest that improvements in lower limb function in less active older individuals following power-based training persist with continued adherence, although this requires further investigation in interventional studies.
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Affiliation(s)
- Alex Ireland
- Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD, UK.
| | - Uwe Mittag
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Hans Degens
- Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD, UK
- Lithuanian Sports University, Kaunas, Lithuania
- University of Medicine and Pharmacy of Târgu Mureș, Târgu Mureș, Rumania
| | - Dieter Felsenberg
- Private Praxis ´Osteology and Orphane Bone Diseases´ and Charité - Campus Benjamin Franklin, Centre of Muscle and Bone Research, Humboldt-University Berlin and Free University, Berlin, Germany
| | - Ari Heinonen
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Erika Koltai
- Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Marko T Korhonen
- Gerontology Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Jamie S McPhee
- Department of Sport and Exercise Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Manchester, UK
| | - Igor Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Rado Pisot
- Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
| | | | - Zsolt Radak
- Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Bostjan Simunic
- Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
| | - Harri Suominen
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Jörn Rittweger
- Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany
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Grönkvist M, Mekjavic I, Ciuha U, Eiken O. Heat Strain with Two Different Ventilation Vests During a Simulated 3-Hour Helicopter Desert Mission. Aerosp Med Hum Perform 2021; 92:248-256. [PMID: 33752788 DOI: 10.3357/amhp.5761.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND: The study investigated the heat strain of personnel operating in the rear cabin of a helicopter during desert-climate missions, and to what extent the strain can be mitigated by use of battery-driven ventilation vests.METHODS: Eight men undertook 3-h simulated flight missions in desert conditions (45C, 10% humidity, solar radiation). Each subject participated in three conditions wearing helicopter flight equipment, including body armor, and either: a ventilation vest with a 3-dimensional mesh (Vent-1), a ventilation vest with a foam sheet incorporating channels to direct the air flow (Vent-2), or a T-shirt (NoVent); each mission comprised a 10-min walk, followed by sitting for 30 min, kneeling on a vibration platform for 2 h, and finally 30 min of sitting. Core temperature, heart rate, skin temperatures and heat flux, oxygen uptake, sweating rate, and subjective ratings were recorded. Evaporative capacity and thermal resistance of the garments were determined using a thermal manikin.RESULTS: All subjects completed the NoVent and Vent-1 conditions, whereas in the Vent-2 condition, one subject finished prematurely due to heat exhaustion. The increase in core temperature was significantly (P 0.01) greater in Novent (0.93C) and Vent-2 (0.88C) than in Vent-1 (0.61C). Evaporative capacity was significantly higher for Vent-1 (7.8 g min1) than for NoVent (4.1 g min1) and Vent-2 (4.4 g min1).DISCUSSION: Helicopter personnel may be at risk of heat exhaustion during desert missions. The risk can be reduced by use of a ventilation vest. However, the cooling efficacy of ventilation vests differs substantially depending on their design and ventilation concept.Grönkvist M, Mekjavic I, Ciuha U, Eiken O. Heat strain with two different ventilation vests during a simulated 3-hour helicopter desert mission. Aerosp Med Hum Perform. 2021; 92(4):248256.
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Ireland A, Mittag U, Degens H, Felsenberg D, Ferretti JL, Heinonen A, Koltai E, Korhonen MT, McPhee JS, Mekjavic I, Piasecki J, Pisot R, Radak Z, Simunic B, Suominen H, Wilks DC, Winwood K, Rittweger J. Greater maintenance of bone mineral content in male than female athletes and in sprinting and jumping than endurance athletes: a longitudinal study of bone strength in elite masters athletes. Arch Osteoporos 2020; 15:87. [PMID: 32524289 PMCID: PMC7286845 DOI: 10.1007/s11657-020-00757-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 05/11/2020] [Indexed: 02/03/2023]
Abstract
UNLABELLED We investigated longitudinal changes in tibia bone strength in master power (jumping and sprinting) and endurance (distance) athletes of both sexes. Bone mass but not cross-sectional moment of inertia was better maintained in power than endurance athletes over time, particularly in men and independent of changes in performance. OBJECTIVE Assessment of effects of sex and athletic discipline (lower limb power events, e.g. sprint running and jumping versus endurance running events) on longitudinal changes in bone strength in masters athletes. METHODS We examined tibia and fibula bone properties at distal (4% distal-proximal tibia length) and proximal (66% length) sites using peripheral quantitative computed tomography (pQCT) in seventy-one track and field masters athletes (30 male, 41 female, age at baseline 57.0 ± 12.2 years) in a longitudinal cohort study that included at least two testing sessions over a mean period of 4.2 ± 3.1 years. Effects of time, as well as time × sex and time × discipline interactions on bone parameters and calf muscle cross-sectional area (CSA), were examined. RESULTS Effects of time were sex and discipline-dependent, even following adjustment for enrolment age, sex and changes in muscle CSA and athletic performance. Male sex and participation in power events was associated with better maintenance of tibia bone mineral content (BMC, an indicator of bone compressive strength) at 4% and 66% sites. In contrast, there was no strong evidence of sex or discipline effects on cross-sectional moment of inertia (CSMI, an indicator of bone bending and torsional strength-P > 0.3 for interactions). Similar sex and discipline-specific changes were also observed in the fibula. CONCLUSIONS Results suggest that male athletes and those participating in lower limb power-based rather than endurance-based disciplines have better maintenance of bone compressive but not bending and torsional strength.
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Affiliation(s)
- Alex Ireland
- grid.25627.340000 0001 0790 5329Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD UK
| | - Uwe Mittag
- grid.7551.60000 0000 8983 7915Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany
| | - Hans Degens
- grid.25627.340000 0001 0790 5329Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD UK ,grid.419313.d0000 0000 9487 602XLithuanian Sports University, Kaunas, Lithuania ,grid.10414.300000 0001 0738 9977University of Medicine and Pharmacy of Targu Mures, Targu Mures, Romania
| | - Dieter Felsenberg
- grid.7468.d0000 0001 2248 7639Osteology and Orphane Bone Diseases and Charité – Campus Benjamin Franklin, Centre of Muscle and Bone Research, Humboldt-University Berlin and Free University, Berlin, Germany
| | - José L. Ferretti
- grid.10814.3c0000 0001 2097 3211Center for P-Ca Metabolism Studies (CEMFoC), National University of Rosario, Rosario, Argentina
| | - Ari Heinonen
- grid.9681.60000 0001 1013 7965Faculty of Sport and Health Sciences, University of Jyväskylä, Jyvaskyla, Finland
| | - Erika Koltai
- grid.472475.70000 0000 9243 1481Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Marko T. Korhonen
- grid.9681.60000 0001 1013 7965Gerontology Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Jamie S. McPhee
- grid.25627.340000 0001 0790 5329Department of Sport and Exercise Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, Manchester, UK
| | - Igor Mekjavic
- grid.11375.310000 0001 0706 0012Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia ,grid.61971.380000 0004 1936 7494Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC Canada
| | - Jessica Piasecki
- grid.25627.340000 0001 0790 5329Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD UK ,grid.12361.370000 0001 0727 0669Sport Health and Performance Enhancement Centre, Nottingham Trent University, Nottingham, UK
| | - Rado Pisot
- Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
| | - Zsolt Radak
- grid.472475.70000 0000 9243 1481Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Bostjan Simunic
- Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
| | - Harri Suominen
- grid.9681.60000 0001 1013 7965Faculty of Sport and Health Sciences, University of Jyväskylä, Jyvaskyla, Finland
| | - Désirée C. Wilks
- grid.25627.340000 0001 0790 5329Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD UK
| | - Keith Winwood
- grid.25627.340000 0001 0790 5329Department of Life Sciences, Musculoskeletal Science and Sports Medicine Research Centre, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester, M1 5GD UK
| | - Jörn Rittweger
- grid.7551.60000 0000 8983 7915Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany ,grid.6190.e0000 0000 8580 3777Department of Pediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany
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Biolo G, Di Girolamo FG, McDonnell A, Fiotti N, Mearelli F, Situlin R, Gonelli A, Dapas B, Giordano M, Lainscak M, Grassi G, Zauli G, Secchiero P, Mekjavic I. Effects of Hypoxia and Bed Rest on Markers of Cardiometabolic Risk: Compensatory Changes in Circulating TRAIL and Glutathione Redox Capacity. Front Physiol 2018; 9:1000. [PMID: 30104982 PMCID: PMC6077233 DOI: 10.3389/fphys.2018.01000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/09/2018] [Indexed: 12/18/2022] Open
Abstract
In chronic diseases, hypoxia and physical inactivity are associated with atherosclerosis progression. In contrast, a lower mortality from coronary artery disease and stroke is observed in healthy humans residing at high altitude in hypoxic environments. Eleven young, male volunteers completed the following 10-day campaigns in a randomized order: hypoxic ambulatory, hypoxic bed rest and normoxic bed rest. Before intervention, subjects were evaluated in normoxic ambulatory condition. Normobaric hypoxia was achieved in a hypoxic facility simulating 4000 m of altitude. Following hypoxia, either in bed rest or ambulatory condition, markers of cardiometabolic risk shifted toward a more atherogenic pattern consisting of: (a) lower levels of total HDL cholesterol and HDL2 sub-fraction and decreased hepatic lipase; (b) activation of systemic inflammation, as determined by C-reactive protein and serum amyloid A; (c) increased plasma homocysteine; (d) decreased delta-5 desaturase index in cell membrane fatty acids, a marker of insulin sensitivity. Bed rest and hypoxia additively decreased total HDL and delta-5 desaturase index. In parallel to the pro-atherogenic effects, hypoxia activated selected anti-atherogenic pathways, consisting of increased circulating TNF-related apoptosis-inducing ligand (TRAIL), a protective factor against atherosclerosis, membrane omega-3 index and erythrocyte glutathione availability. Hypoxia mediated changes in TRAIL concentrations and redox glutathione capacity (i.e., GSH/GSSG ratio) were greater in ambulatory conditions (+34 ± 6% and +87 ± 31%, respectively) than in bed rest (+17 ± 7% and +2 ± 27% respectively). Hypoxia-induced cardiometabolic risk is blunted by moderate level of physical activity as compared to bed rest. TRAIL and glutathione redox capacity may contribute to the positive interaction between physical activity and hypoxia. Highlights: – Hypoxia and bed rest activate metabolic and inflammatory markers of atherogenesis. – Hypoxia and physical activity activate selected anti-atherogenic pathways. – Hypoxia and physical activity positive interaction involves TRAIL and glutathione.
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Affiliation(s)
- Gianni Biolo
- Clinica Medica, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Filippo G Di Girolamo
- Clinica Medica, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Adam McDonnell
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Nicola Fiotti
- Clinica Medica, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Filippo Mearelli
- Clinica Medica, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Roberta Situlin
- Clinica Medica, Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Arianna Gonelli
- Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, University of Ferrara, Ferrara, Italy
| | - Barbara Dapas
- Department of Life Science, University of Trieste, Trieste, Italy
| | - Mauro Giordano
- Ospedale Clinicizzato di Marcianise, Dipartimento di Scienze Mediche, Chirurgiche, Neurologiche, Metaboliche e dell'Invecchiamento, Università degli Studi della Campania Luigi Vanvitelli, Marcianise, Italy
| | - Mitja Lainscak
- Department of Internal Medicine, General Hospital Murska Sobota and Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Gabriele Grassi
- Department of Life Science, University of Trieste, Trieste, Italy
| | - Giorgio Zauli
- Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, University of Ferrara, Ferrara, Italy
| | - Paola Secchiero
- Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, University of Ferrara, Ferrara, Italy
| | - Igor Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
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Dolenc Groselj L, Morrison S, Mirnik D, Korsic S, Eiken O, Mekjavic I. Bed rest and hypoxic exposure affect sleep architecture and breathing stability. Sleep Med 2017. [DOI: 10.1016/j.sleep.2017.11.230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pattyn N, Fernandez H, Mairesse O, Mekjavic I, Meeusen R. Sleep, exercise and hypoxia: How an altitude deployment creates unexpected risks. J Sci Med Sport 2017. [DOI: 10.1016/j.jsams.2017.09.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Šket R, Treichel N, Debevec T, Eiken O, Mekjavic I, Schloter M, Vital M, Chandler J, Tiedje JM, Murovec B, Prevoršek Z, Stres B. Hypoxia and Inactivity Related Physiological Changes (Constipation, Inflammation) Are Not Reflected at the Level of Gut Metabolites and Butyrate Producing Microbial Community: The PlanHab Study. Front Physiol 2017; 8:250. [PMID: 28522975 PMCID: PMC5416748 DOI: 10.3389/fphys.2017.00250] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 04/10/2017] [Indexed: 12/12/2022] Open
Abstract
We explored the assembly of intestinal microbiota in healthy male participants during the run-in (5 day) and experimental phases [21-day normoxic bed rest (NBR), hypoxic bedrest (HBR)], and hypoxic ambulation (HAmb) in a strictly controlled laboratory environment, balanced fluid, and dietary intakes, controlled circadian rhythm, microbial ambiental burden, and 24/7 medical surveillance. The fraction of inspired O2 (FiO2) and partial pressure of inspired O2 (PiO2) were 0.209 and 133.1 ± 0.3 mmHg for NBR and 0.141 ± 0.004 and 90.0 ± 0.4 mmHg for both hypoxic variants (HBR and HAmb; ~4,000 m simulated altitude), respectively. A number of parameters linked to intestinal transit spanning Bristol Stool Scale, defecation rates, zonulin, α1-antitrypsin, eosinophil derived neurotoxin, bile acids, reducing sugars, short chain fatty acids, total soluble organic carbon, water content, diet composition, and food intake were measured (167 variables). The abundance, structure, and diversity of butyrate producing microbial community were assessed using the two primary bacterial butyrate synthesis pathways, butyryl-CoA: acetate CoA-transferase (but) and butyrate kinase (buk) genes. Inactivity negatively affected fecal consistency and in combination with hypoxia aggravated the state of gut inflammation (p < 0.05). In contrast, gut permeability, various metabolic markers, the structure, diversity, and abundance of butyrate producing microbial community were not significantly affected. Rearrangements in the butyrate producing microbial community structure were explained by experimental setup (13.4%), experimentally structured metabolites (12.8%), and gut metabolite-immunological markers (11.9%), with 61.9% remaining unexplained. Many of the measured parameters were found to be correlated and were hence omitted from further analyses. The observed progressive increase in two immunological intestinal markers suggested that the transition from healthy physiological state toward the developed symptoms of low magnitude obesity-related syndromes was primarily driven by the onset of inactivity (lack of exercise in NBR) that were exacerbated by systemic hypoxia (HBR) and significantly alleviated by exercise, despite hypoxia (HAmb). Butyrate producing community in colon exhibited apparent resilience toward short-term modifications in host exercise or hypoxia. Progressive constipation (decreased intestinal motility) and increased local inflammation marker suggest that changes in microbial colonization and metabolism were taking place at the location of small intestine.
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Affiliation(s)
- Robert Šket
- Department of Animal Science, Biotechnical Faculty, University of LjubljanaLjubljana, Slovenia
| | - Nicole Treichel
- Research Unit for Comparative Microbiome Analysis, Helmholtz Zentrum München - German Research Center for Environmental HealthNeuherberg, Germany
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan InstituteLjubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of TechnologyStockholm, Sweden
| | - Igor Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan InstituteLjubljana, Slovenia
| | - Michael Schloter
- Research Unit for Comparative Microbiome Analysis, Helmholtz Zentrum München - German Research Center for Environmental HealthNeuherberg, Germany
| | - Marius Vital
- Center for Microbial Ecology, Michigan State UniversityEast Lansing, MI, USA
| | - Jenna Chandler
- Center for Microbial Ecology, Michigan State UniversityEast Lansing, MI, USA
| | - James M Tiedje
- Center for Microbial Ecology, Michigan State UniversityEast Lansing, MI, USA
| | - Boštjan Murovec
- Laboratory for Artificial Sight and Automation, Faculty of Electrical Sciences, University of LjubljanaLjubljana, Slovenia
| | - Zala Prevoršek
- Department of Animal Science, Biotechnical Faculty, University of LjubljanaLjubljana, Slovenia
| | - Blaž Stres
- Department of Animal Science, Biotechnical Faculty, University of LjubljanaLjubljana, Slovenia.,Center for Clinical Neurophysiology, Faculty of Medicine, University of LjubljanaLjubljana, Slovenia
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Strewe C, Zeller R, Feuerecker M, Hoerl M, Kumprej I, Crispin A, Johannes B, Debevec T, Mekjavic I, Schelling G, Choukèr A. PlanHab study: assessment of psycho-neuroendocrine function in male subjects during 21 d of normobaric hypoxia and bed rest. Stress 2017; 20:131-139. [PMID: 28166699 DOI: 10.1080/10253890.2017.1292246] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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] [Indexed: 10/20/2022] Open
Abstract
Immobilization and hypoxemia are conditions often seen in patients suffering from severe heart insufficiency or primary pulmonary diseases (e.g. fibrosis, emphysema). In future planned long-duration and exploration class space missions (including habitats on the moon and Mars), healthy individuals will encounter such a combination of reduced physical activity and oxygen tension by way of technical reasons and the reduced gravitational forces. These overall unconventional extraterrestrial conditions can result in yet unknown consequences for the regulation of stress-permissive, psycho-neuroendocrine responses, which warrant appropriate measures in order to mitigate foreseeable risks. The Planetary Habitat Simulation Study (PlanHab) investigated these two space-related conditions: bed rest as model of reduced gravity and normobaric hypoxia, with the aim of examining their influence on psycho-neuroendocrine responses. We hypothesized that both conditions independently increase measures of psychological stress and enhance neuroendocrine markers of stress, and that these effects would be exacerbated by combined treatment. The cross-over study composed of three interventions (NBR, normobaric normoxic horizontal bed rest; HBR, normobaric hypoxic horizontal bed rest; HAMB, normobaric hypoxic ambulatory confinement) with 14 male subjects during three sequential campaigns separated by 4 months. The psychological state was determined through three questionnaires and principal neuroendocrine responses were evaluated by measuring cortisol in saliva, catecholamine in urine, and endocannabinoids in blood. The results revealed no effects after 3 weeks of normobaric hypoxia on psycho-neuroendocrine responses. Conversely, bed rest induced neuroendocrine alterations that were not influenced by hypoxia.
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Affiliation(s)
- C Strewe
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
| | - R Zeller
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
| | - M Feuerecker
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
| | - M Hoerl
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
| | - I Kumprej
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
- b Department of Automation, Biocybernetics and Robotics , Jozef Stefan Institute , Ljubljana , Slovenia
| | - A Crispin
- c Department of Biometry and Epidemiology, Klinikum Großhadern , University of Munich , Munich , Germany
| | - B Johannes
- d Department of Space Physiology , Institute of Aerospace Medicine, German Aerospace Center (DLR) , Cologne , Germany
| | - T Debevec
- b Department of Automation, Biocybernetics and Robotics , Jozef Stefan Institute , Ljubljana , Slovenia
| | - I Mekjavic
- b Department of Automation, Biocybernetics and Robotics , Jozef Stefan Institute , Ljubljana , Slovenia
| | - G Schelling
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
| | - A Choukèr
- a Department of Anaesthesiology , Klinikum Großhadern, University of Munich, Stress and Immunology Lab , Munich , Germany
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Simpson EJ, Debevec T, Eiken O, Mekjavic I, Macdonald IA. PlanHab: the combined and separate effects of 16 days of bed rest and normobaric hypoxic confinement on circulating lipids and indices of insulin sensitivity in healthy men. J Appl Physiol (1985) 2016; 120:947-55. [PMID: 26769956 DOI: 10.1152/japplphysiol.00897.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 01/11/2016] [Indexed: 01/03/2023] Open
Abstract
PlanHab is a planetary habitat simulation study. The atmosphere within future space habitats is anticipated to have reduced Po2, but information is scarce as to how physiological systems may respond to combined exposure to moderate hypoxia and reduced gravity. This study investigated, using a randomized-crossover design, how insulin sensitivity, glucose tolerance, and circulating lipids were affected by 16 days of horizontal bed rest in normobaric normoxia [NBR: FiO2 = 0.209; PiO2 = 133.1 (0.3) mmHg], horizontal bed rest in normobaric hypoxia [HBR: FiO2 = 0.141 (0.004); PiO2 = 90.0 (0.4) mmHg], and confinement in normobaric hypoxia combined with daily moderate intensity exercise (HAMB). A mixed-meal tolerance test, with arterialized-venous blood sampling, was performed in 11 healthy, nonobese men (25-45 yr) before (V1) and on the morning ofday 17of each intervention (V2). Postprandial glucose and c-peptide response were increased at V2 of both bed rest interventions (P< 0.05 in each case), with c-peptide:insulin ratio higher at V2 in HAMB and HBR, both in the fed and fasted state (P< 0.005 in each case). Fasting total cholesterol was reduced at V2 in HAMB [-0.47 (0.36) mmol/l;P< 0.005] and HBR [-0.55 (0.41) mmol/l;P< 0.005]. Fasting HDL was lower at V2 in all interventions, with the reduction observed in HBR [-0.30 (0.21) mmol/l] greater than that measured in HAMB [-0.13 (0.14) mmol/l;P< 0.005] and NBR [-0.17 (0.15) mmol/l;P< 0.05]. Hypoxia did not alter the adverse effects of bed rest on insulin sensitivity and glucose tolerance but appeared to increase insulin clearance. The negative effect of bed rest on HDL was compounded in hypoxia, which may have implications for long-term health of those living in future space habitats.
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Affiliation(s)
- Elizabeth J Simpson
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom;
| | - Tadej Debevec
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, Swedish Aerospace Physiology Centre, Royal Institute of Technology, Stockholm, Sweden
| | - Igor Mekjavic
- Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana, Slovenia
| | - Ian A Macdonald
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom
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Morrison S, Pangerc A, Eiken O, Mekjavic I, Dolenc-Groselj L. Alterations in central sleep apnoea following 10-d exposure to hypoxia: influence of exercise. Sleep Med 2013. [DOI: 10.1016/j.sleep.2013.11.512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Eiken O, Mekjavic I, Sundblad P, Kölegård R. G tolerance vis-à-vis pressure-distension and pressure-flow relationships of leg arteries. Eur J Appl Physiol 2012; 112:3619-27. [PMID: 22350358 DOI: 10.1007/s00421-012-2349-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 01/31/2012] [Indexed: 11/30/2022]
Abstract
During increased gravitoinertial (G) load in the head-to-foot direction, pressures in dependent vascular beds are commonly raised to levels capable of distending precapillary vessels, which, in turn, may reduce arterial pressure, and hence compromise the capacity to withstand G load (G tolerance). We hypothesized that distensibility in precapillary leg vessels would be lower in a group of subjects possessing high G tolerance (H; n = 7; relaxed G tolerance = 6.6 ± 0.8 G) than in a group with low G tolerance (L; n = 8; G tolerance = 3.9 ± 0.3 G). The groups were matched with regard to gender, age, weight, height, and resting arterial pressure. Arterial pressure-distension and pressure-flow experiments were performed with the subject supine in a pressure chamber with a lower leg protruding to the outside. Increased intravascular pressure in the blood vessels of the outside leg was accomplished by stepwise increasing chamber pressure to 240 mmHg. Diameter and flow in the posterior tibial artery were measured by ultrasonographic/Doppler techniques. Pressure-induced increments in arterial diameter and flow were more pronounced (p < 0.03) in the L (14.1 ± 4.2% and 32 ± 21 ml/min respectively) than in the H (1.7 ± 5.0% and 1.6 ± 25 ml/min) group, and the pressure thresholds at which these increments commenced were lower (by 52 and 48 mmHg, respectively) in the L than in the H group (p < 0.04). Negative correlations were observed between G tolerance and the increments in diameter and flow (p < 0.02). Thus, the wall stiffness of precapillary leg vessels is greater in individuals with high relaxed G tolerance; whether a causal relationship exists remains to be established.
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Affiliation(s)
- Ola Eiken
- Department of Environmental Physiology, School of Technology and Health, Royal Institute of Technology, Berzelius v 13, Solna, 171 65 Stockholm, Sweden.
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12
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Gasperin M, Juricic D, Musizza B, Mekjavic I. A model-based approach to the evaluation of flame-protective garments. ISA Trans 2008; 47:198-210. [PMID: 18262527 DOI: 10.1016/j.isatra.2007.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Revised: 12/11/2007] [Accepted: 12/18/2007] [Indexed: 05/25/2023]
Abstract
High-quality protective garments are essential in many occupational assignments, e.g., in the petrochemical industry and for firefighting. The problem addressed in this paper is how to objectively asses the performance of protective garments designed to resist fire. We present a system based on a flame mannequin equipped with an array of temperature sensors that provide information about the temperature on the mannequin's surface during exposure to fire. Particular attention is devoted to reconstructing the heat flux reaching the mannequin's surface on the basis of the available temperature records (the inverse heat-conduction problem). The estimated heat flux is used in a skin-simulation model to predict the level of injury that would occur in human exposed to the same heat. The paper includes a novel computational procedure based on a detailed model of the temperature sensor and a numerical solution of the accompanying heat equation. The effectiveness of the solution is demonstrated with experimental data.
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Affiliation(s)
- Matej Gasperin
- Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
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13
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Hamman R, Longridge NS, Mekjavic I, Dickinson J. Effect of age and training schedules on balance improvement exercises using visual biofeedback. J Otolaryngol 1995; 24:221-9. [PMID: 8551534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
There has been a growing popularity and success rate of balance rehabilitation programs, and this success is paralleled by the growth of technology, making available instruments that provide objective, quantitative, and immediate results. The Balance Master is such a commercially available instrument, consisting of a dual-force platform connected to a micro-computer that provides visual feedback of the centre of gravity (COG) in relation to the theoretical limits of stability. Spontaneous body sway can be measured in a static central position, or in peripheral positions around the limits of stability (peripheral sway area). The trajectory between targets can also be analyzed in terms of time (transition time) and accuracy (path error) of transition, which gives a quantitative measure of dynamic movement of the COG. This study examined the practice effect that occurs while using this instrument over repeated sessions for two schedules of training (daily and weekly) and over two age groups (20-35 years, and 60-75 years). Each group completed a series of postural exercises, with an assessment of static and dynamic postural variables before and after training, and at approximately 3 and 6 weeks post-training. Spontaneous body sway was measured with eyes open, eyes closed, and with visual feedback of the COG. No significant changes were observed in these variables as measured over the four standard assessment occasions. Peripheral sway area and path error decreased significantly for both the daily and weekly training groups from pre- to post-training, and these skills were retained over both retention tests, whereas the tendency toward decreasing transition time was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R Hamman
- Department of Kinesiology, Simon Fraser University
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Hamman RG, Mekjavic I, Mallinson AI, Longridge NS. Training effects during repeated therapy sessions of balance training using visual feedback. Arch Phys Med Rehabil 1992; 73:738-44. [PMID: 1642525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Visual biofeedback of postural sway is currently being investigated as a therapeutic technique to reduce postural instability in selected patient populations. Before the efficacy of this type of therapy can be determined in a clinical setting, the performance curves of a normal population doing the static and dynamic balance training exercises have to be delineated. Two groups of normal subjects were evaluated during a daily and weekly protocol of dynamic balance exercises using visual feedback of their center of gravity (COG) and theoretical limits of stability. Static stability in a central position was measured with eyes open, eyes closed, and with visual feedback of the COG in a pre-therapy to post-therapy assessment. No significant change was observed in any of these variables from the pre-therapy to the post-therapy evaluation; as well there was no difference between the scores of both groups. Dynamic variables were evaluated in both a pre-therapy to post-therapy assessment, and over the course of therapy. Each of these protocols required the subjects to track targets representing 75% of their limits of stability on a computer screen with their COG. The time taken and the accuracy to move the COG cursor from target to target, as well as the body sway upon reaching the target were evaluated. Transition time and sway area both decreased significantly (p less than 0.01) from the pre-therapy to the post-therapy assessment for both groups, with path error decreasing significantly for the daily therapy group only. No significant difference was demonstrated between groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R G Hamman
- School of Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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15
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16
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Brownlie L, Mekjavic I, Gartshore I, Mutch B, Banister E. The influence of apparel on aerodynamic drag in running. Ann Physiol Anthropol 1987; 6:133-43. [PMID: 3675773 DOI: 10.2114/ahs1983.6.133] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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17
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Younger R, Longridge NS, Mekjavic I. Effect of reduced atmospheric pressure on patients with fluctuating hearing loss due to Ménière's disease. J Otolaryngol 1984; 13:76-82. [PMID: 6726851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Subjective symptomatic and objective audiologic effects of reduced atmospheric pressure on patients with confirmed fluctuating hearing loss due to Ménière's disease were statistically assessed on a prospective basis. The effect of hypobaric environments on absolute hearing thresholds was investigated in 10 normal subjects at 6,500 ft. Absolute hearing threshold levels obtained at altitude, after one hour altitude exposure, and on descent to normobaric conditions were compared with levels obtained prior to the hypobaric exposure. The results indicated slightly increasing sensitivity of the audiometer headphones with altitude and an insignificant difference in hearing threshold when comparing the differing experimental conditions. The Ménière's disease study group of 16 patients was followed symptomatically and audiologically for one year prehypobaric exposure and for one month post-treatment. The results in this group utilizing the same experimental protocol as with normal subjects indicated a mild deterioration of hearing in the lower frequencies (1,000, 2,000 Hz and calculating the Ménière's pure tone average) despite significant improvements in the vertigo and disability components of their disease.
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Sharratt MT, Banister EW, Mekjavic I, Legge B. PHYSIOLOGICAL AND PHYSICAL STATUS OF FREESTYLE AND GRECO-ROMAN JUNIOR WORLD WRESTLING CHAMPIONS. Med Sci Sports Exerc 1982. [DOI: 10.1249/00005768-198202000-00241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Mekjavic I, Tominic I. Standard potentials of silver-silver bromide electrode and related thermodynamic quantities in (5, 10 and 15 wt-%) 2-butanol-water mixtures. J Electroanal Chem (Lausanne) 1978. [DOI: 10.1016/s0022-0728(78)80026-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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