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Oberholzer L, Aamaas NS, Hallén J. Changes in cycling economy and fractional utilization of V̇O 2peak during a 40-min maximal effort exercise test with acute hypobaric hypoxia corresponding to 2800 m of altitude. Scand J Med Sci Sports 2024; 34:e14511. [PMID: 37828810 DOI: 10.1111/sms.14511] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/16/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023]
Abstract
INTRODUCTION Peak oxygen uptake (V̇O2peak ) declines by ~7% per 1000 m of increasing altitude, whereas exercise performance seems reduced to a lesser extent. For example, 800-10 000 m track and field performances are decreased by 0.4%-2.4% above 1000 m as compared to below and some studies show similar drops in cycling performance. A greater decline in V̇O2peak than in endurance performance with altitude suggests a higher fractional utilization of V̇O2peak (%V̇O2peak ). Therefore, we hypothesized that the %V̇O2peak is higher with acute hypoxic exposure than near sea level. METHODS Sixteen lowlanders (8 women, age: 31 ± 7 years [mean ± SD], body mass: 68 ± 8 kg, V̇O2peak : 60 ± 8 mL min-1 kg-1 ) underwent cycling testing in a hypobaric hypoxic chamber on 6 test days, three conducted at 300 m and three at 2800 m of acute altitude. At both altitudes, V̇O2peak was determined, and during a 40-min all out maximal effort time trial (TT), mean power output (MPO) and mean V̇O2 (%V̇O2peak ) were assessed. RESULTS V̇O2peak decreased by 11.2 ± 3.0% (p < 0.001), while MPO during the TT declined by 10.7 ± 3.1% (p < 0.001) at 2800 m as compared to 300 m. During the TT, %V̇O2peak was higher at altitude, corresponding to 75.9 ± 4.5% at 300 m and 78.8 ± 4.2% at 2800 m (p = 0.011), and cycling economy (mL O2 kJ-1 ) was poorer (+3.4 ± 2.7%, p < 0.001). CONCLUSION The %V̇O2peak was higher during a cycling TT at 2800 m of altitude than near sea level, while cycling economy was poorer. This resulted in a similar reduction in performance and V̇O2peak . Future studies should address the physiological mechanisms underlying the elevated %V̇O2peak .
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Affiliation(s)
- Laura Oberholzer
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | | | - Jostein Hallén
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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Oberholzer L, Montero D, Robach P, Siebenmann C, Ryrsøe CK, Bonne TC, Breenfeldt Andersen A, Bejder J, Karlsen T, Edvardsen E, Rønnestad BR, Hamarsland H, Cepeda-Lopez AC, Rittweger J, Treff G, Ahlgrim C, Almquist NW, Hallén J, Lundby C. Determinants and reference values for blood volume and total hemoglobin mass in women and men. Am J Hematol 2024; 99:88-98. [PMID: 38032792 DOI: 10.1002/ajh.27162] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 10/04/2023] [Accepted: 10/12/2023] [Indexed: 12/02/2023]
Abstract
Blood volume (BV) is an important clinical parameter and is usually reported per kg of body mass (BM). When fat mass is elevated, this underestimates BV/BM. One aim was to study if differences in BV/BM related to sex, age, and fitness would decrease if normalized to lean body mass (LBM). The analysis included 263 women and 319 men (age: 10-93 years, body mass index: 14-41 kg/m2 ) and 107 athletes who underwent assessment of BV and hemoglobin mass (Hbmass ), body composition, and cardiorespiratory fitness. BV/BM was 25% lower (70.3 ± 11.3 and 80.3 ± 10.8 mL/kgBM ) in women than men, respectively, whereas BV/LBM was 6% higher in women (110.9 ± 12.5 and 105.3 ± 11.2 mL/kgLBM ). Hbmass /BM was 34% lower (8.9 ± 1.4 and 11.5 ± 11.2 g/kgBM ) in women than in men, respectively, but only 6% lower (14.0 ± 1.5 and 14.9 ± 1.5 g/kgLBM )/LBM. Age did not affect BV. Athlete's BV/BM was 17.2% higher than non-athletes, but decreased to only 2.5% when normalized to LBM. Of the variables analyzed, LBM was the strongest predictor for BV (R2 = .72, p < .001) and Hbmass (R2 = .81, p < .001). These data may only be valid for BV/Hbmass when assessed by CO re-breathing. Hbmass /LBM could be considered a valuable clinical matrix in medical care aiming to normalize blood homeostasis.
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Affiliation(s)
- Laura Oberholzer
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - David Montero
- Department of Medicine, School of Clinical Medicine/Public Health, The University of Hongkong, Hongkong, China
| | - Paul Robach
- Ecole Nationale des Sports de Montagne, site de l'Ecole Nationale de Ski et d'Alpinisme, Chamonix, France
| | | | - Camilla Koch Ryrsøe
- Department of Infectious Diseases and Pulmonary Medicine, Nordsjaellands University Hospital, Hillerød, Denmark
| | - Thomas C Bonne
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | | | - Jacob Bejder
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Trine Karlsen
- Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway
- Cardiac Exercise Research Group, Department of Circulation and Medical Imaging, NTNU-Norwegian University of Science of Technology, Trondheim, Norway
| | - Elisabeth Edvardsen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Bent R Rønnestad
- Section for Health and Exercise Physiology, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Håvard Hamarsland
- Section for Health and Exercise Physiology, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Ana C Cepeda-Lopez
- Health Sciences Division, University of Monterrey (UDEM), Monterrey, Mexico
| | - Jörn Rittweger
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Cologne, Germany
- Department of Pediatrics and Adolescent Medicine, University Hospital Cologne, Cologne, Germany
| | - Gunnar Treff
- Division of Sports and Rehabilitation Medicine, Ulm University Hospital, Ulm, Germany
| | - Christoph Ahlgrim
- University Heart Center Freiburg, Medical Center-University of Freiburg, Bad Krozingen, Germany
| | - Nicki Winfield Almquist
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | - Jostein Hallén
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Carsten Lundby
- Section for Health and Exercise Physiology, Inland Norway University of Applied Sciences, Lillehammer, Norway
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Doutreleau S, Ulliel-Roche M, Hancco I, Bailly S, Oberholzer L, Robach P, Brugniaux JV, Pichon A, Stauffer E, Perger E, Parati G, Verges S. Cardiac remodelling in the highest city in the world: effects of altitude and chronic mountain sickness. Eur J Prev Cardiol 2022; 29:2154-2162. [PMID: 35929776 DOI: 10.1093/eurjpc/zwac166] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/20/2022] [Accepted: 08/03/2022] [Indexed: 01/11/2023]
Abstract
AIMS A unique Andean population lives in the highest city of the world (La Rinconada, 5100 m, Peru) and frequently develops a maladaptive syndrome, termed chronic mountain sickness (CMS). Both extreme altitude and CMS are a challenge for the cardiovascular system. This study aims to evaluate cardiac remodelling and pulmonary circulation at rest and during exercise in healthy and CMS highlanders. METHODS AND RESULTS Highlanders living permanently at 3800 m (n = 23) and 5100 m (n = 55) with (n = 38) or without CMS (n = 17) were compared with 18 healthy lowlanders. Rest and exercise echocardiography were performed to describe cardiac remodelling, pulmonary artery pressure (PAP), and pulmonary vascular resistance (PVR). Total blood volume (BV) and haemoglobin mass were determined in all people. With the increase in the altitude of residency, the right heart dilated with an impairment in right ventricle systolic function, while the left heart exhibited a progressive concentric remodelling with Grade I diastolic dysfunction but without systolic dysfunction. Those modifications were greater in moderate-severe CMS patients. The mean PAP was higher both at rest and during exercise in healthy highlanders at 5100 m. The moderate-severe CMS subjects had a higher PVR at rest and a larger increase in PAP during exercise. The right heart remodelling was correlated with PAP, total BV, and SpO2. CONCLUSION Healthy dwellers at 5100 m exhibit both right heart dilatation and left ventricle concentric remodelling with diastolic dysfunction. Those modifications are even more pronounced in moderate-severe CMS subjects and could represent the limit of the heart's adaptability before progression to heart failure.
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Affiliation(s)
- Stéphane Doutreleau
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Mathilde Ulliel-Roche
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Ivan Hancco
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Sébastien Bailly
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Laura Oberholzer
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Paul Robach
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France.,National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Julien V Brugniaux
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
| | - Aurélien Pichon
- Laboratoire MOVE EA 6314, Faculté des Sciences du Sport, Université de Poitiers, Poitiers, France
| | - Emeric Stauffer
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Team 'Vascular Biology and Red Blood Cell', Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Elisa Perger
- Istituto Auxologico Italiano, IRCCS, Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy
| | - Gianfranco Parati
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Samuel Verges
- HP2 Laboratory, Univ. Grenoble Alpes, Inserm, CHU Grenoble Alpes, Avenue Kimberley, 38 434 Grenoble, France
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Perger E, Baillieul S, Esteve F, Pichon A, Bilo G, Soranna D, Doutreleau S, Savina Y, Ulliel-Roche M, Brugniaux JV, Stauffer E, Oberholzer L, Howe C, Hannco I, Lombardi C, Tamisier R, Pepin JL, Verges S, Parati G. Nocturnal hypoxemia, blood pressure, vascular status and chronic mountain sickness in the highest city in the world. Ann Med 2022; 54:1884-1893. [PMID: 35786084 PMCID: PMC9258438 DOI: 10.1080/07853890.2022.2091791] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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] [Indexed: 11/28/2022] Open
Abstract
INTRODUCTION Chronic mountain sickness (CMS) is a condition characterized by excessive erythrocytosis in response to chronic hypobaric hypoxia. CMS frequently triggers cardiorespiratory diseases such as pulmonary hypertension and right or left heart failure. Ambient hypoxia might be further amplified night-time by intermittent hypoxia related to sleep-disordered breathing (SDB) so that sleep disturbance may be an important feature of CMS. Our aim was to characterize in a cross-sectional study nocturnal hypoxaemia, SDB, blood pressure (BP), arterial stiffness and carotid intima-media thickness (CIMT) in highlanders living at extreme altitude. METHODS Men aged 18 to 55 years were prospectively recruited. Home sleep apnoea test, questionnaires (short-form health survey; Montreal cognitive assessment; Pittsburgh Sleep Questionnaire Index and the Insomnia severity index), 24-h ambulatory BP monitoring, CIMT and arterial stiffness were evaluated in 3 groups: i) Andean lowlanders (sea-level); ii) highlanders living at 3,800 m and iii) highlanders living at 5,100 m. Analyses were conducted in sub-groups according to 1) CMS severity 2) healthy subjects living at the three different altitude. RESULTS Ninety-two males were evaluated at their living altitudes. Among the 54 highlanders living at 5,100 m, subjects with CMS showed lower mean nocturnal oxygen saturation (SpO2), SpO2 nadir, lower pulse wave velocity and higher nocturnal BP variability than those with no-CMS. Lower nocturnal SpO2 nadir was associated with higher CMS severity (ß= -0.14, p=.009). Among the 55 healthy subjects, healthy highlanders at 5,100 m were characterized by lower scores on quality of life and sleep quality scales and lower mean SpO2 compared to lowlanders. CONCLUSIONS Lower nocturnal SpO2 and higher nocturnal BP variability are associated with CMS severity in individuals living permanently at high altitude. The role of lower SpO2 and higher nocturnal BP variability in the cardiovascular progression of CMS and in the overall prognosis of the disease need to be evaluated in further studies.
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Affiliation(s)
- Elisa Perger
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
| | - Sébastien Baillieul
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - François Esteve
- Inserm UA7, Rayonnement Synchrotron pour la Recherche Biomédicale, Grenoble, France
| | - Aurélien Pichon
- Faculty of Sport Sciences, Université de Poitiers, Laboratory Mobility, aging & exercise (MOVE, EA6314), Poitiers, France
| | - Gzregorz Bilo
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
| | - Davide Soranna
- Istituto Auxologico Italiano, IRCCS, Biostatistics unit, Milan, Italy
| | - Stéphane Doutreleau
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Yann Savina
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Mathilde Ulliel-Roche
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Julien V Brugniaux
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Emeric Stauffer
- Interuniversity Laboratory of Human Movement Biology (LIBM, EA7424), "Red Blood cell and Vascular Biology" team, Univ Lyon - University Claude Bernard Lyon 1, Villeurbanne, France
| | - Laura Oberholzer
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Connor Howe
- Centre for Heart, Lung, and Vascular Health, University of British Columbia, Kelowna, Canada
| | - Ivan Hannco
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Carolina Lombardi
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
| | - Renaud Tamisier
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Jean-Louis Pepin
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Samuel Verges
- Univ. Grenoble Alpes, HP2 Laboratory, INSERM U1300, CHU Grenoble Alpes, Grenoble, France
| | - Gianfranco Parati
- Istituto Auxologico Italiano, IRCCS, Sleep Disorders Center & Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Milan, Italy.,Biostatistic Unit, University of Milano-Bicocca, Milan, Italy
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Lundby C, Oberholzer L. MO524: Gender Differences in Intravascular Volumes Vanish if Expressed per Lean Body Mass. Nephrol Dial Transplant 2022. [DOI: 10.1093/ndt/gfac072.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
BACKGROUND AND AIMS
Blood volume (BV) is an important clinical parameter and is usually expressed relative to body weight (BW), but is inappropriate with elevated fat mass. We hypothesized that established differences in BV and hemoglobin mass (Hbmass) between male and female would vanish if expressed per lean body mass (LBM) instead of BW. We furthermore aimed to establish reference values for BV, plasma volume, red blood cell volume and Hbmass in women and men for clinical use.
METHOD
Blood volumes (carbon monoxide rebreathing) and body composition (DXA scan) were determined in 225 female and 280 healthy men (18–93 years, BMI range: 16.4–40.6).
RESULTS
As expected, female absolute BV was 1570 mL [CI 95% (1429.66–1709.87)]; P-value ≤.001) less than in male, and also when expressed per BW female had lower values than male (Figure 1A) [CI 95% (8.06–12.02); P-value ≤.001]. However, when expressed to LBM, females had 6.3 mL higher value than males [CI 95% (−8.80 to −3.86); P-value ≤ .001] (Figure 2A). In a similar manner, absolute Hbmass was 303 g greater in male [CI 95% = (283.99–322.09); P-value ≤ .001] and also greater when expressed pr BW [CI 95% (2.37–2.88); P-value ≤ .001] (Figure 1D). However, when normalized to LBM, differences were greatly diminished −0.84 [CI 95% (0.53–1.15); P-value ≤ .001] (Figure 2B). Per year of older age, a man gains 0.14 [0.06–0.22] mL blood/LBM (P = .0012) and a woman gains 0.13 [0.04–0.22] mL (P = .0032), but the increase in blood volume is not different between men and women (no interaction effect, P = .92). Similar observations as for BV and Hbmass were also made for red blood cell volume and plasma volume (See Figs. 1 and 2).
CONCLUSION
The principal finding is that when BV and Hbmass are expressed relative to LBM, the known differences in intravascular volumes and Hbmass between male and female largely disappear. Furthermore, the relation between LBM and intracvascular volumes and Hbmass is preserved with advancing age. Taken together, LBM is a very strong predictor for intravascular volumes and Hbmass in healthy humans and could be considered a valuable clinical matrix in medical care aiming to normalize intravascular volumes in patients such as chronic kidney failure and heart failure.
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Pilmark NS, Oberholzer L, Halling JF, Kristensen JM, Bønding CP, Elkjær I, Lyngbæk M, Elster G, Siebenmann C, Holm NF, Birk JBB, Larsen EL, Meinild-Lundby AK, Wojtaszewski JF, Pilegaard H, Poulsen H, Pedersen BK, Hansen KB, Karstoft K. Skeletal muscle adaptations to exercise are not influenced by metformin treatment in humans: secondary analyses of two randomised, clinical trials. Appl Physiol Nutr Metab 2021; 47:309-320. [PMID: 34784247 DOI: 10.1139/apnm-2021-0194] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Metformin and exercise both improve glycemic control, but in vitro studies have indicated that an interaction between metformin and exercise occurs in skeletal muscle, suggesting a blunting effect of metformin on exercise training adaptations. Two studies (a double-blind, parallel-group, randomized clinical trial conducted in 29 glucose-intolerant individuals and a double-blind, cross-over trial conducted in 15 healthy lean males) were included in this paper. In both studies, the effect of acute exercise +/- metformin treatment on different skeletal muscle variables, previously suggested to be involved in a pharmaco-physiological interaction between metformin and exercise, was assessed. Furthermore, in the parallel-group trial, the effect of 12 weeks of exercise training was assessed. Skeletal muscle biopsies were obtained before and after acute exercise and 12 weeks of exercise training, and mitochondrial respiration, oxidative stress and AMPK activation was determined. Metformin did not significantly affect the effects of acute exercise or exercise training on mitochondrial respiration, oxidative stress or AMPK activation, indicating that the response to acute exercise and exercise training adaptations in skeletal muscle is not affected by metformin treatment. Further studies are needed to investigate whether an interaction between metformin and exercise is present in other tissues, e.g. the gut. Trial registration: ClinicalTrials.gov (NCT03316690 and NCT02951260). Novelty bullets • Metformin does not affect exercise-induced alterations in mitochondrial respiratory capacity in human skeletal muscle • Metformin does not affect exercise-induced alterations in systemic levels of oxidative stress nor emission of reactive oxygen species from human skeletal muscle • Metformin does not affect exercise-induced AMPK activation in human skeletal muscle.
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Affiliation(s)
- Nanna Skytt Pilmark
- Rigshospitalet, 53146, Centre for Physical Activity Research (CFAS), Copenhagen, Denmark;
| | - Laura Oberholzer
- Center for Physical Activity Research, University Hospital of Copenhagen, Blegdamsvej 9, Copenhagen, Denmark, 2100;
| | - Jens Frey Halling
- university of copenhagen, department of biology, , copenhagen, Denmark;
| | - Jonas M Kristensen
- University of Copenhagen, Denmark, Department of Nutrition, Exercise and Sports,, copenhagen, Denmark;
| | | | - Ida Elkjær
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Mark Lyngbæk
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Grit Elster
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Christoph Siebenmann
- Institute of Mountain Emergency Medicine,, EURAC Research, Bolzano, Italy, bolzano, Italy;
| | - Niels Frederich Holm
- Center for Physical Activity Research, University Hospital of Copenhagen, Copenhagen, Denmark;
| | - Jesper Bratz Bratz Birk
- University of Copenhagen, Denmark, Department of Nutrition, Exercise and Sports,, copenhagen, Denmark;
| | - Emil List Larsen
- Copenhagen University Hospital, 53146, Department of Clinical Pharmacology, Bispebjerg and Frederiksberg Hospital, Kobenhavn, Denmark;
| | | | - J F Wojtaszewski
- University of Copenhagen, Denmark, Department of Nutrition, Exercise and Sports,, copenhagen, Denmark;
| | | | - Henrik Poulsen
- Copenhagen University Hospital, 53146, Department of Clinical Pharmacology, Bispebjerg and Frederiksberg Hospital, Kobenhavn, Denmark;
| | - Bente Klarlund Pedersen
- Rigshospitalet, 53146, Centre of Inflammation and Metabolism / Centre for Physical Activity Research (CIM/CFAS), København, Denmark;
| | - Katrine Bagge Hansen
- Steno Diabetes Center Copenhagen, 53138, Steno Diabetes Center Copenhagen, Gentofte, Denmark, Gentofte, Denmark;
| | - Kristian Karstoft
- Rigshospitalet, 53146, Centre for Physical Activity Research (CFAS), Blegdamsvej 9, Copenhagen, Denmark, 2100.,Bispebjerg Hospital, 53166, Department of Clinical Pharmacology, Copenhagen, Denmark, 2400;
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Pilmark NS, Lyngbæk M, Oberholzer L, Elkjær I, Petersen-Bønding C, Kofoed K, Siebenmann C, Kellenberger K, van Hall G, Abildgaard J, Ellingsgaard H, Lauridsen C, Ried-Larsen M, Pedersen BK, Hansen KB, Karstoft K. The interaction between metformin and physical activity on postprandial glucose and glucose kinetics: a randomised, clinical trial. Diabetologia 2021; 64:397-409. [PMID: 32979074 DOI: 10.1007/s00125-020-05282-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 08/10/2020] [Indexed: 01/04/2023]
Abstract
AIMS/HYPOTHESIS The aim of this parallel-group, double-blinded (study personnel and participants), randomised clinical trial was to assess the interaction between metformin and exercise training on postprandial glucose in glucose-intolerant individuals. METHODS Glucose-intolerant (2 h OGTT glucose of 7.8-11.0 mmol/l and/or HbA1c of 39-47 mmol/mol [5.7-6.5%] or glucose-lowering-medication naive type 2 diabetes), overweight/obese (BMI 25-42 kg/m2) individuals were randomly allocated to a placebo study group (PLA, n = 15) or a metformin study group (MET, n = 14), and underwent 3 experimental days: BASELINE (before randomisation), MEDICATION (after 3 weeks of metformin [2 g/day] or placebo treatment) and TRAINING (after 12 weeks of exercise training in combination with metformin/placebo treatment). Training consisted of supervised bicycle interval sessions with a mean intensity of 64% of Wattmax for 45 min, 4 times/week. The primary outcome was postprandial glucose (mean glucose concentration) during a mixed meal tolerance test (MMTT), which was assessed on each experimental day. For within-group differences, a group × time interaction was assessed using two-way repeated measures ANOVA. Between-group changes of the outcomes at different timepoints were compared using unpaired two-tailed Student's t tests. RESULTS Postprandial glucose improved from BASELINE to TRAINING in both the PLA group and the MET group (∆PLA: -0.7 [95% CI -1.4, 0.0] mmol/l, p = 0.05 and ∆MET: -0.7 [-1.5, -0.0] mmol/l, p = 0.03), with no between-group difference (p = 0.92). In PLA, the entire reduction was seen from MEDICATION to TRAINING (-0.8 [-1.3, -0.1] mmol/l, p = 0.01). Conversely, in MET, the entire reduction was observed from BASELINE to MEDICATION (-0.9 [-1.6, -0.2] mmol/l, p = 0.01). The reductions in mean glucose concentration during the MMTT from BASELINE to TRAINING were dependent on differential time effects: in the PLA group, a decrease was observed at timepoint (t) = 120 min (p = 0.009), whereas in the MET group, a reduction occurred at t = 30 min (p < 0.001). V̇O2peak increased 15% (4.6 [3.3, 5.9] ml kg-1 min-1, p < 0.0001) from MEDICATION to TRAINING and body weight decreased (-4.0 [-5.2, -2.7] kg, p < 0.0001) from BASELINE to TRAINING, with no between-group differences (p = 0.7 and p = 0.5, respectively). CONCLUSIONS/INTERPRETATION Metformin plus exercise training was not superior to exercise training alone in improving postprandial glucose. The differential time effects during the MMTT suggest an interaction between the two modalities. FUNDING The Beckett foundation, A.P Møller Foundation, DDA, the Research Foundation of Rigshospitalet and Trygfonden. TRIAL REGISTRATION ClinicalTrials.gov (NCT03316690). Graphical abstract.
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Affiliation(s)
- Nanna S Pilmark
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Mark Lyngbæk
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Laura Oberholzer
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ida Elkjær
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Christina Petersen-Bønding
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Katja Kofoed
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Christoph Siebenmann
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Katja Kellenberger
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Section for Elite Sport, Swiss Federal Institute of Sports, Magglingen, Switzerland
| | - Gerrit van Hall
- Biomedical Sciences, Faculty of Health & Medical Science, University of Copenhagen, Copenhagen, Denmark
- Clinical Metabolomics Core Facility, Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark
| | - Julie Abildgaard
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark
| | - Helga Ellingsgaard
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Lauridsen
- Department of Diagnostic Radiology, Copenhagen University Hospital, Copenhagen, Denmark
- Copenhagen University College, Copenhagen N, Denmark
| | - Mathias Ried-Larsen
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Bente K Pedersen
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Kristian Karstoft
- Centre for Physical Activity Research (CFAS), Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
- Department of Clinical Pharmacology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark.
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8
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Oberholzer L, Bonne TC, Breenfeldt Andersen A, Bejder J, Højgaard Christensen R, Baastrup Nordsborg N, Lundby C. Reproducibility of the CO rebreathing technique with a lower CO dose and a shorter rebreathing duration at sea level and at 2320 m of altitude. Scand J Clin Lab Invest 2020; 80:590-599. [PMID: 32955368 DOI: 10.1080/00365513.2020.1818282] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Total hemoglobin mass (Hbmass) is routinely assessed in studies by the carbon monoxide (CO) rebreathing. Its clinical application is often hindered due to the consequent rise in carboxyhemoglobin (%HbCO) and the concern of CO toxicity. We tested the reproducibility of the CO rebreathing with a CO dose of 0.5 mL/kg body mass (CO0.5) compared to 1.5 mL/kg (CO1.5) and when shortening the CO rebreathing protocol. Therefore, CO rebreathing was performed 1×/day in eight healthy individuals on four consecutive days. On each day, either CO0.5 (CO0.5-1 and CO0.5-2) or CO1.5 (CO1.5-1 and CO1.5-2) was administered. Venous blood samples to determine %HbCO and quantify Hbmass were obtained prior to, and at 6 (T6), 8 (T8) and 10 min (T10) of CO rebreathing. This protocol was tested at sea level and at 2320 m to investigate the altitude-related measurement error. At sea level, the mean difference (95% limits of agreement) in Hbmass between CO0.5-1 and CO0.5-2 was 26 g (-26; 79 g) and between CO1.5-1 and CO1.5-2, it was 17 g (-18; 52 g). The respective typical error (TE) corresponded to 2.4% (CO0.5) and 1.5% (CO1.5), while it was 6.5% and 3.0% at 2320 m. With CO0.5, shortening the CO rebreathing resulted in a TE for Hbmass of 4.4% (T8 vs. T10) and 14.1% (T6 vs T10) and with CO1.5, TE was 1.6% and 5.8%. In conclusion, the CO dose and rebreathing time for the CO rebreathing procedure can be decreased at the cost of a measurement error ranging from 1.5-14.1%.
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Affiliation(s)
- Laura Oberholzer
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Christian Bonne
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Jacob Bejder
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Carsten Lundby
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Innland University of Applied Sciences, Lillehammer, Norway
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9
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Stauffer E, Loyrion E, Hancco I, Waltz X, Ulliel‐Roche M, Oberholzer L, Robach P, Pichon A, Brugniaux JV, Bouzat P, Doutreleau S, Connes P, Verges S. Blood viscosity and its determinants in the highest city in the world. J Physiol 2020; 598:4121-4130. [DOI: 10.1113/jp279694] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 05/07/2020] [Indexed: 12/14/2022] Open
Affiliation(s)
- Emeric Stauffer
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424 Team ‘Biologie vasculaire et du globule rouge’ Université Claude Bernard Lyon 1 Université de Lyon France
- Laboratoire d'Excellence du Globule Rouge (Labex GR‐Ex) PRES Sorbonne Paris France
- Centre de Médecine du Sommeil et des Maladies Respiratoires Hospices Civils de Lyon Hôpital Croix Rousse Lyon France
| | - Emmanuelle Loyrion
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Ivan Hancco
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Xavier Waltz
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Mathilde Ulliel‐Roche
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Laura Oberholzer
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research Rigshospitalet University of Copenhagen Copenhagen Denmark
| | - Paul Robach
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
- National School for Mountain Sports Site of the National School for Skiing and Mountaineering (ENSA) Chamonix France
| | | | - Julien V. Brugniaux
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Pierre Bouzat
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Stéphane Doutreleau
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
| | - Philippe Connes
- Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424 Team ‘Biologie vasculaire et du globule rouge’ Université Claude Bernard Lyon 1 Université de Lyon France
- Laboratoire d'Excellence du Globule Rouge (Labex GR‐Ex) PRES Sorbonne Paris France
- Institut Universitaire de France Paris France
| | - Samuel Verges
- HP2 laboratory Université Grenoble Alpes, Inserm, CHU Grenoble Alpes, Faculté de Médecine Grenoble 38000 France
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10
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Mikkelsen CJ, Junge N, Piil JF, Morris NB, Oberholzer L, Siebenmann C, Lundby C, Nybo L. Prolonged Heat Acclimation and Aerobic Performance in Endurance Trained Athletes. Front Physiol 2019; 10:1372. [PMID: 31749712 PMCID: PMC6843002 DOI: 10.3389/fphys.2019.01372] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [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: 07/28/2019] [Accepted: 10/16/2019] [Indexed: 11/17/2022] Open
Abstract
Heat acclimation (HA) involves physiological adaptations that directly promote exercise performance in hot environments. However, for endurance-athletes it is unclear if adaptations also improve aerobic capacity and performance in cool conditions, partly because previous randomized controlled trial (RCT) studies have been restricted to short intervention periods. Prolonged HA was therefore deployed in the present RCT study including 21 cyclists [38 ± 2 years, 184 ± 1 cm, 80.4 ± 1.7 kg, and maximal oxygen uptake (VO2max) of 58.1 ± 1.2 mL/min/kg; mean ± SE] allocated to either 5½ weeks of training in the heat [HEAT (n = 12)] or cool control [CON (n = 9)]. Training registration, familiarization to test procedures, determination of VO2max, blood volume and 15 km time trial (TT) performance were assessed in cool conditions (14°C) during a 2-week lead-in period, as well as immediately pre and post the intervention. Participants were instructed to maintain total training volume and complete habitual high intensity intervals in normal settings; but HEAT substituted part of cool training with 28 ± 2 sessions in the heat (1 h at 60% VO2max in 40°C; eliciting core temperatures above 39°C in all sessions), while CON completed all training in cool conditions. Acclimation for HEAT was verified by lower sweat sodium [Na+], reduced steady-state heart rate and improved submaximal exercise endurance in the heat. However, when tested in cool conditions both peak power output and VO2max remained unchanged for HEAT (pre 60.0 ± 1.5 vs. 59.8 ± 1.3 mL O2/min/kg). TT performance tested in 14°C was improved for HEAT and average power output increased from 298 ± 6 to 315 ± 6 W (P < 0.05), but a similar improvement was observed for CON (from 294 ± 11 to 311 ± 10 W). Based on the present findings, we conclude that training in the heat was not superior compared to normal (control) training for improving aerobic power or TT performance in cool conditions.
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Affiliation(s)
- C. Jacob Mikkelsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nicklas Junge
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jacob F. Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Nathan B. Morris
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Laura Oberholzer
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
| | - Christoph Siebenmann
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Carsten Lundby
- Centre for Physical Activity Research, Copenhagen University Hospital, Copenhagen, Denmark
- Innland Norway University of Applied Sciences, Lillehammer, Norway
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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11
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Oberholzer L, Siebenmann C, Mikkelsen CJ, Junge N, Piil JF, Morris NB, Goetze JP, Meinild Lundby AK, Nybo L, Lundby C. Hematological Adaptations to Prolonged Heat Acclimation in Endurance-Trained Males. Front Physiol 2019; 10:1379. [PMID: 31749713 PMCID: PMC6842970 DOI: 10.3389/fphys.2019.01379] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/18/2019] [Indexed: 11/13/2022] Open
Abstract
Heat acclimation is associated with plasma volume (PV) expansion that occurs within the first week of exposure. However, prolonged effects on hemoglobin mass (Hbmass) are unclear as intervention periods in previous studies have not allowed sufficient time for erythropoiesis to manifest. Therefore, Hbmass, intravascular volumes, and blood volume (BV)-regulating hormones were assessed with 5½ weeks of exercise-heat acclimation (HEAT) or matched training in cold conditions (CON) in 21 male cyclists [(mean ± SD) age: 38 ± 9 years, body weight: 80.4 ± 7.9 kg, VO2peak: 59.1 ± 5.2 ml/min/kg]. HEAT (n = 12) consisted of 1 h cycling at 60% VO2peak in 40°C for 5 days/week in addition to regular training, whereas CON (n = 9) trained exclusively in cold conditions (<15°C). Before and after the intervention, Hbmass and intravascular volumes were assessed by carbon monoxide rebreathing, while reticulocyte count and BV-regulating hormones were measured before, after 2 weeks and post intervention. Total training volume during the intervention was similar (p = 0.282) between HEAT (509 ± 173 min/week) and CON (576 ± 143 min/week). PV increased (p = 0.004) in both groups, by 303 ± 345 ml in HEAT and 188 ± 286 ml in CON. There was also a main effect of time (p = 0.038) for Hbmass with +34 ± 36 g in HEAT and +2 ± 33 g in CON and a tendency toward a higher increase in Hbmass in HEAT compared to CON (time × group interaction: p = 0.061). The Hbmass changes were weakly correlated to alterations in PV (r = 0.493, p = 0.023). Reticulocyte count and BV-regulating hormones remained unchanged for both groups. In conclusion, Hbmass was slightly increased following prolonged training in the heat and although the mechanistic link remains to be revealed, the increase could represent a compensatory response in erythropoiesis secondary to PV expansion.
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Affiliation(s)
- Laura Oberholzer
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Christoph Siebenmann
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - C. Jacob Mikkelsen
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicklas Junge
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jacob F. Piil
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nathan B. Morris
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens P. Goetze
- Department of Clinical Biochemistry, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne-Kristine Meinild Lundby
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Lars Nybo
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Lundby
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Innland Norway University of Applied Sciences, Lillehammer, Norway
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12
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Oberholzer L, Siebenmann C, Mikkelsen CJ, Junge N, Piil JF, Morris NB, Goetze JP, Meinild Lundby AK, Nybo L, Lundby C. Hematological Adaptations to Prolonged Heat Acclimation in Endurance-Trained Males. Front Physiol 2019. [PMID: 31749713 DOI: 10.3389/fphys.2019.01379, 10.3389/fpls.2019.01379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Heat acclimation is associated with plasma volume (PV) expansion that occurs within the first week of exposure. However, prolonged effects on hemoglobin mass (Hbmass) are unclear as intervention periods in previous studies have not allowed sufficient time for erythropoiesis to manifest. Therefore, Hbmass, intravascular volumes, and blood volume (BV)-regulating hormones were assessed with 5½ weeks of exercise-heat acclimation (HEAT) or matched training in cold conditions (CON) in 21 male cyclists [(mean ± SD) age: 38 ± 9 years, body weight: 80.4 ± 7.9 kg, VO2peak: 59.1 ± 5.2 ml/min/kg]. HEAT (n = 12) consisted of 1 h cycling at 60% VO2peak in 40°C for 5 days/week in addition to regular training, whereas CON (n = 9) trained exclusively in cold conditions (<15°C). Before and after the intervention, Hbmass and intravascular volumes were assessed by carbon monoxide rebreathing, while reticulocyte count and BV-regulating hormones were measured before, after 2 weeks and post intervention. Total training volume during the intervention was similar (p = 0.282) between HEAT (509 ± 173 min/week) and CON (576 ± 143 min/week). PV increased (p = 0.004) in both groups, by 303 ± 345 ml in HEAT and 188 ± 286 ml in CON. There was also a main effect of time (p = 0.038) for Hbmass with +34 ± 36 g in HEAT and +2 ± 33 g in CON and a tendency toward a higher increase in Hbmass in HEAT compared to CON (time × group interaction: p = 0.061). The Hbmass changes were weakly correlated to alterations in PV (r = 0.493, p = 0.023). Reticulocyte count and BV-regulating hormones remained unchanged for both groups. In conclusion, Hbmass was slightly increased following prolonged training in the heat and although the mechanistic link remains to be revealed, the increase could represent a compensatory response in erythropoiesis secondary to PV expansion.
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Affiliation(s)
- Laura Oberholzer
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Christoph Siebenmann
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - C Jacob Mikkelsen
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nicklas Junge
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jacob F Piil
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Nathan B Morris
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens P Goetze
- Department of Clinical Biochemistry, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anne-Kristine Meinild Lundby
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Lars Nybo
- Department of Nutrition, Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Lundby
- The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.,Innland Norway University of Applied Sciences, Lillehammer, Norway
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13
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Montero D, Diaz-Canestro C, Oberholzer L, Lundby C. The role of blood volume in cardiac dysfunction and reduced exercise tolerance in patients with diabetes. Lancet Diabetes Endocrinol 2019; 7:807-816. [PMID: 31255583 DOI: 10.1016/s2213-8587(19)30119-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/20/2019] [Accepted: 03/27/2019] [Indexed: 11/18/2022]
Abstract
Blood volume is an integral component of the cardiovascular system, and fundamental to discerning the pathophysiology of multiple cardiovascular conditions leading to exercise intolerance. Based on a systematic search of controlled studies assessing blood volume, in this Personal View we describe how hypovolaemia is a prevalent characteristic of patients with diabetes, irrespective of sex, age, and physical activity levels. Multiple endocrine and haematological mechanisms contribute to hypovolaemia in diabetes. The regulation of intravascular volumes is altered by sustained hyperglycaemia and hypertension. Chronic activation of endocrine systems controlling fluid homeostasis, such as the renin-angiotensin-aldosterone system and vasopressin axis, has a role in progressive kidney desensitisation and diabetic nephropathy. Furthermore, albumin loss from the intravascular compartment reduces the osmotic potential of plasma to retain water. Hypovolaemia also affects the loading conditions and filling of the heart in diabetes. The elucidation of modifiable volumetric traits will plausibly have major health benefits in the diabetes population.
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Affiliation(s)
- David Montero
- Faculty of Kinesiology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada.
| | - Candela Diaz-Canestro
- Faculty of Kinesiology, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Laura Oberholzer
- Department of Clinical Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Lundby
- Inland Norway University of Applied Sciences, Lillehammer, Norway
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14
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Siebenmann C, Ryrsø CK, Oberholzer L, Fisher JP, Hilsted LM, Rasmussen P, Secher NH, Lundby C. Hypoxia-induced vagal withdrawal is independent of the hypoxic ventilatory response in men. J Appl Physiol (1985) 2019; 126:124-131. [DOI: 10.1152/japplphysiol.00701.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxia increases heart rate (HR) in humans by sympathetic activation and vagal withdrawal. However, in anaesthetized dogs hypoxia increases vagal activity and reduces HR if pulmonary ventilation does not increase and we evaluated whether that observation applies to awake humans. Ten healthy males were exposed to 15 min of normoxia and hypoxia (10.5% O2), while respiratory rate and tidal volume were volitionally controlled at values identified during spontaneous breathing in hypoxia. End-tidal CO2 tension was clamped at 40 mmHg by CO2 supplementation. β-Adrenergic blockade by intravenous propranolol isolated vagal regulation of HR. During spontaneous breathing, hypoxia increased ventilation by 3.2 ± 2.1 l/min ( P = 0.0033) and HR by 8.9 ± 5.5 beats/min ( P < 0.001). During controlled breathing, respiratory rate (16.3 ± 3.2 vs. 16.4 ± 3.3 breaths/min) and tidal volume (1.05 ± 0.27 vs. 1.06 ± 0.24 l) were similar for normoxia and hypoxia, whereas the HR increase in hypoxia persisted without (8.6 ± 10.2 beats/min) and with (6.6 ± 5.6 beats/min) propranolol. Neither controlled breathing ( P = 0.80), propranolol ( P = 0.64), nor their combination ( P = 0.89) affected the HR increase in hypoxia. Arterial pressure was unaffected ( P = 0.48) by hypoxia across conditions. The hypoxia-induced increase in HR during controlled breathing and β-adrenergic blockade indicates that hypoxia reduces vagal activity in humans even when ventilation does not increase. Vagal withdrawal in hypoxia seems to be governed by the arterial chemoreflex rather than a pulmonary inflation reflex in humans. NEW & NOTEWORTHY Hypoxia accelerates the heart rate of humans by increasing sympathetic activity and reducing vagal activity. Animal studies have indicated that hypoxia-induced vagal withdrawal is governed by a pulmonary inflation reflex that is activated by the increased pulmonary ventilation in hypoxia. The present findings, however, indicate that humans experience vagal withdrawal in hypoxia even if ventilation does not increase, indicating that vagal withdrawal is governed by the arterial chemoreflex rather than a pulmonary inflation reflex.
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Affiliation(s)
- Christoph Siebenmann
- The Centre for Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Camilla K. Ryrsø
- The Centre for Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Laura Oberholzer
- The Centre for Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - James P. Fisher
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, United Kingdom
| | - Linda M. Hilsted
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | | | - Niels H. Secher
- Department of Anaesthesia, The Copenhagen Muscle Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Lundby
- The Centre for Inflammation and Metabolism and the Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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15
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Montero D, Oberholzer L, Haider T, Breenfeldt-Andersen A, Dandanell S, Meinild-Lundby AK, Maconochie H, Lundby C. Increased capillary density in skeletal muscle is not associated with impaired insulin sensitivity induced by bed rest in healthy young men. Appl Physiol Nutr Metab 2018; 43:1334-1340. [DOI: 10.1139/apnm-2018-0195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Physical inactivity alters glucose homeostasis in skeletal muscle, potentially developing into overt metabolic disease. The present study sought to investigate the role of skeletal muscle capillarization in glucose tolerance and insulin sensitivity (IS) using a classic human model of physical inactivity. Thirteen healthy males (age = 23 ± 2 years) underwent 4 days of full-time supervised and diet-controlled bed rest. Oral glucose tolerance test, indices of IS (quantitative insulin sensitivity check index (QUICKI), Matsuda index), as well as skeletal muscle biopsies with measurement of fiber type distribution, fiber cross-sectional area (FCSA), capillary-to-fiber ratio (C/F ratio), and capillary density (CD) were assessed prior to and after bed rest. Body weight and composition were unaltered by bed rest. Fasting glucose/insulin ratio (G0/I0 ratio) (−25%, P = 0.016), QUICKI (−7%, P = 0.023), and Matsuda index (−24%, P = 0.003) diminished with bed rest. Skeletal muscle FCSA decreased (−737.4 ± 763.2 μm−2 (−12%), P = 0.005) while C/F ratio was preserved, resulting in augmented CD (+93.9 ± 91.5 capillaries·mm−2 (+37%), P = 0.003) with bed rest. No association was detected between changes in skeletal muscle variables and metabolic outcomes. Independently of bed rest-induced effects, a positive linear relationship was detected between C/F ratio and G0/I0 ratio (β = 17.09, P = 0.021). In conclusion, impaired glucose homeostasis with bed rest is not prevented nor associated with enhanced skeletal muscle capillarization in healthy individuals.
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Affiliation(s)
- David Montero
- Department of Cardiology, University Hospital of Zurich, Switzerland
| | - Laura Oberholzer
- Center for Physical Activity Research, University Hospital of Copenhagen, Denmark
| | - Thomas Haider
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Switzerland
| | | | - Sune Dandanell
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Switzerland
| | | | - Hannah Maconochie
- Center for Physical Activity Research, University Hospital of Copenhagen, Denmark
| | - Carsten Lundby
- Center for Physical Activity Research, University Hospital of Copenhagen, Denmark
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16
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Dandanell S, Meinild-Lundby AK, Andersen AB, Lang PF, Oberholzer L, Keiser S, Robach P, Larsen S, Rønnestad BR, Lundby C. Determinants of maximal whole-body fat oxidation in elite cross-country skiers: Role of skeletal muscle mitochondria. Scand J Med Sci Sports 2018; 28:2494-2504. [DOI: 10.1111/sms.13298] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 08/24/2018] [Accepted: 09/08/2018] [Indexed: 12/27/2022]
Affiliation(s)
- Sune Dandanell
- Institute of Physiology; University of Zürich; Zürich Switzerland
- Department of Biomedical Sciences, Center for Healthy Aging, XLab; University of Copenhagen; Copenhagen Denmark
| | | | | | - Paul F. Lang
- Institute of Physiology; University of Zürich; Zürich Switzerland
| | - Laura Oberholzer
- Institute of Physiology; University of Zürich; Zürich Switzerland
| | - Stefanie Keiser
- Institute of Physiology; University of Zürich; Zürich Switzerland
| | - Paul Robach
- Ecole Nationale des Sports de Montagne, site de l’Ecole Nationale de Ski et d’Alpinisme; Chamonix France
| | - Steen Larsen
- Department of Biomedical Sciences, Center for Healthy Aging, XLab; University of Copenhagen; Copenhagen Denmark
| | | | - Carsten Lundby
- Institute of Physiology; University of Zürich; Zürich Switzerland
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17
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Breenfeldt Andersen A, Oberholzer L, Haider T, Meinild-Lundby AK, Fagoni N. From spaceflight to blood doping: Devices for assessing haemoglobin mass and intravascular volumes. Acta Physiol (Oxf) 2018; 224:e13081. [PMID: 29704889 DOI: 10.1111/apha.13081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- A. Breenfeldt Andersen
- Zurich Center of Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zürich; Zürich Switzerland
- Department of Nutrition, Exercise and Sports (NEXS); University of Copenhagen; Copenhagen Denmark
| | - L. Oberholzer
- Zurich Center of Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zürich; Zürich Switzerland
| | - T. Haider
- Zurich Center of Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zürich; Zürich Switzerland
| | - A. -K. Meinild-Lundby
- Zurich Center of Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zürich; Zürich Switzerland
| | - N. Fagoni
- Zurich Center of Integrative Human Physiology (ZIHP); Institute of Physiology; University of Zürich; Zürich Switzerland
- Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
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18
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Larsen S, Lundby AM, Dandanell S, Oberholzer L, Keiser S, Andersen AB, Haider T, Lundby C. Four days of bed rest increases intrinsic mitochondrial respiratory capacity in young healthy males. Physiol Rep 2018; 6:e13793. [PMID: 30221830 PMCID: PMC6139706 DOI: 10.14814/phy2.13793] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [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] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 11/24/2022] Open
Abstract
Bed rest leads to impaired glucose tolerance. Whether this is linked to maladaptation's in skeletal muscle mitochondrial function and in particular to the level of reactive oxygen species (ROS) is at present unknown. The aim of this longitudinal study was to quantify skeletal muscle mitochondrial function (respiratory capacity and ROS production) together with glucose tolerance after 4 days of strict bed rest in healthy young male subjects (n = 14). Mitochondrial function was determined in permeabilized muscle fibers using high-resolution respirometry and fluorometry, mitochondrial content (citrate synthase [CS] activity) and antioxidant protein expression levels were assessed in parallel to this. Glucose tolerance was determined by means of oral glucose tolerance tests. Intrinsic mitochondrial respiratory capacity was augmented after the bed rest period (CI + IIP : 0.43 ± 0.12 vs. 0.55 ± 0.14 [pmol/sec/mg]/CS activity), due to a decreased CS activity (158 ± 39 vs. 129 ± 25 mU/mg dw.). No differences were observed in ROS production (per mg of tissue or when normalized to CS activity). Furthermore, the protein content for catalase was increased while superoxide dismutase and glutathione peroxidase remained unaffected. These findings were accompanied by an impaired glucose tolerance after the bed rest period (Matsuda index: 12 ± 6 vs. 9 ± 5). The change in intrinsic mitochondrial respiratory capacity could be an early indication in the development of impaired glucose tolerance. The increased catalase protein content might explain that no change was seen in ROS production after 4 days of bed rest. Whether these findings can be extrapolated to lifestyle-dependent decrements in physical activity and the development of type-2-diabetes remains unknown.
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Affiliation(s)
- Steen Larsen
- XlabCenter for Healthy AgingDepartment of Biomedical SciencesFaculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
- Clinical Research CentreMedical University of BialystokBialystokPoland
| | | | - Sune Dandanell
- XlabCenter for Healthy AgingDepartment of Biomedical SciencesFaculty of Health SciencesUniversity of CopenhagenCopenhagenDenmark
- Institute of PhysiologyUniversity of ZürichZürichSwitzerland
| | | | - Stefanie Keiser
- Institute of PhysiologyUniversity of ZürichZürichSwitzerland
| | | | - Thomas Haider
- Institute of PhysiologyUniversity of ZürichZürichSwitzerland
| | - Carsten Lundby
- Institute of PhysiologyUniversity of ZürichZürichSwitzerland
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19
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Montero D, Breenfeldt-Andersen A, Oberholzer L, Haider T. Effect of Exercise on Arterial Stiffness: Is There a Ceiling Effect? Am J Hypertens 2017; 30:1069-1072. [PMID: 28985267 DOI: 10.1093/ajh/hpx145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 07/28/2017] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Whether arterial stiffness (AS) can be improved by regular exercise in healthy individuals remains equivocal according to cross-sectional and longitudinal studies assessing arterial properties at discrete time points. The purpose of the present study was to pinpoint the time course of training-induced adaptations in central AS. METHODS Aorta characteristic impedance (Zc) and carotid distensibility (CD) were determined with ultrasonography prior to (week 0) and across 8 weeks (weeks 2, 4, and 8) of supervised endurance training (ET) (3 × 60 minutes cycle ergometry sessions per week), in 9 previously untrained healthy normotensive adults (27 ± 4 years) with no history of cardiovascular disease. Exercise capacity was assessed by maximal oxygen consumption (VO2max) elicited by incremental ergometry. RESULTS VO2max increased throughout the ET intervention (+12% from week 0 to week 8, P < 0.001, P for linear trend <0.001). Systolic blood pressure rose with ET (+7% from week 0 to week 8, P = 0.019, P for linear trend <0.001). Aorta Zc augmented from week 0 to week 8 of ET in all individuals (+38%, P = 0.003, P for linear trend = 0.002). CD did not significantly differ among time points (P = 0.196) although a linear decreasing trend was detected (P = 0.016). CONCLUSIONS Central AS augments during a conventional ET intervention that effectively enhances aerobic exercise capacity in young individuals. This suggests that normal, healthy elastic arteries are not amendable to improvement unless impairment is present.
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Affiliation(s)
- David Montero
- Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Andreas Breenfeldt-Andersen
- Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Laura Oberholzer
- Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Thomas Haider
- Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
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20
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Montero D, Dandanell S, Oberholzer L, Keiser S, Breenfeldt-Andersen A, Haider T, Merlini M, Meinild-Lundby AK, Lundby C. Combined effects of physical inactivity and acute hyperglycemia on arterial distensibility. Vasc Med 2017. [PMID: 28643554 DOI: 10.1177/1358863x17712103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Arterial distensibility, an independent predictor of cardiovascular events, is transiently increased with acute hyperglycemia (AHG) in healthy individuals. Whether this response interacts with physical inactivity remains unknown. We examined the effects of short-term bed rest (BR) on the response of carotid artery distensibility (CD) to AHG, and the influence of underlying changes in insulin resistance and blood volume. CD was assessed with ultrasonography before as well as 30 and 120 minutes following ingestion of 75 g of glucose prior to and after 3 days of BR in 15 healthy male volunteers. Plasma insulin/glucose concentrations and blood volumes were concomitantly determined. On day 4 of BR, blood volume was re-established to pre-BR levels by albumin infusion and CD and insulin/glucose concentrations were determined as in the previous experimental days. Basal CD was not affected by BR. AHG increased CD before and after BR but reached a higher peak increment after BR (12% vs 60% at 30 min OGTT, p=0.028). BR also increased the plasma insulin concentration during AHG ( p=0.007). In regression analyses, plasma insulin and glucose concentrations were positively correlated to CD, particularly after BR ( r=0.31, p<0.05). Restoration of the BR-induced loss (5%) in blood volume did not affect the response of CD to AHG. In conclusion, short-term physical inactivity strongly accentuates the initial increase in CD in response to AHG in healthy individuals. This effect is associated with concomitant increases in circulating insulin concentration attributable to early insulin resistance.
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Affiliation(s)
- David Montero
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland.,2 University Heart Center, Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Sune Dandanell
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Laura Oberholzer
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Stefanie Keiser
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Andreas Breenfeldt-Andersen
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Thomas Haider
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Mario Merlini
- 3 Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Anne-Kristine Meinild-Lundby
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Carsten Lundby
- 1 Zurich Center for Integrative Human Physiology (ZIHP), Institute of Physiology, University of Zurich, Zurich, Switzerland
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21
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Montero D, Breenfeldt-Andersen A, Oberholzer L, Haider T, Goetze JP, Meinild-Lundby AK, Lundby C. Erythropoiesis with endurance training: dynamics and mechanisms. Am J Physiol Regul Integr Comp Physiol 2017; 312:R894-R902. [DOI: 10.1152/ajpregu.00012.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/06/2017] [Accepted: 03/31/2017] [Indexed: 11/22/2022]
Abstract
The purpose of the present study was to characterize the progression of red blood cell volume (RBCV) expansion and potential volumetric and endocrine regulators of erythropoiesis during endurance training (ET). Nine healthy, untrained volunteers (age = 27 ± 4 yr) underwent supervised ET consisting of 3–4 × 60 min cycle ergometry sessions per week for 8 wk. Plasma volume (PV), RBCV, and overnight fasting hematological markers were determined before and at weeks 2, 4, and 8 of ET. In addition, plasma erythropoietin (EPO), cortisol, copeptin, and proatrial natriuretic peptide concentrations were measured during a 3-h morning period at baseline and postexercise at weeks 1 and 8. PV increased from baseline (2,405 ± 335 ml) at weeks 2, 4, and 8 (+374 ± 194, +505 ± 156, and +341 ± 160 ml, respectively, P < 0.001). Increases in RBCV from baseline (1,737 ± 442 ml) were manifested at week 4 (+109 ± 114 ml, P = 0.030) and week 8 (+205 ± 109 ml, P = 0.001). Overnight fasting plasma EPO concentration increased from baseline (11.3 ± 4.8 mIU/ml) at week 2 (+2.5 ± 2.8 mIU·ml−1, P = 0.027) and returned to baseline concentration at weeks 4 and 8. Higher 3-h-postexercise EPO concentration was observed at week 1 (11.6 mIU/ml) compared with week 8 (8.4 ± 3.9 mIU/ml, P = 0.009) and baseline (9.0 ± 4.2 mIU/ml, P = 0.019). Linear relationships between EPO concentration and hematocrit (β = −56.2, P < 0.001) and cortisol (β = 0.037, P < 0.001) were detected throughout the ET intervention. In conclusion, ET leads to mild, transient increases in circulating EPO concentration, concurring with early PV expansion and lowered hematocrit, preceding gradual RBCV enhancement.
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Affiliation(s)
- David Montero
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Andreas Breenfeldt-Andersen
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark; and
| | - Laura Oberholzer
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Thomas Haider
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Jens P. Goetze
- Department of Clinical Biochemistry, Copenhagen, and Aarhus University, Aarhus, Denmark
| | - Anne-Kristine Meinild-Lundby
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Carsten Lundby
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
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22
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Fagoni N, Breenfeldt Andersen A, Oberholzer L, Haider T, Meinild Lundby AK, Lundby C. Reliability and validity of non-invasive determined haemoglobin mass and blood volumes. Clin Physiol Funct Imaging 2017; 38:240-245. [DOI: 10.1111/cpf.12406] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 11/07/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Nazzareno Fagoni
- Zurich Center of Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
- Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
| | - Andreas Breenfeldt Andersen
- Zurich Center of Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
- Department of Nutrition, Exercise and Sports (NEXS); University of Copenhagen; Copenhagen Denmark
| | - Laura Oberholzer
- Zurich Center of Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
| | - Thomas Haider
- Zurich Center of Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
| | - Anne-Kristine Meinild Lundby
- Zurich Center of Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
| | - Carsten Lundby
- Zurich Center of Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
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23
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Dandanell S, Oberholzer L, Keiser S, Andersen AB, Haider T, Hilty MP, Meinild-Lundby AK, Lundby C. Effect of alterations in blood volume with bed rest on glucose tolerance. J Appl Physiol (1985) 2016; 121:1098-1105. [PMID: 27633742 DOI: 10.1152/japplphysiol.00624.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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: 07/11/2016] [Accepted: 09/12/2016] [Indexed: 11/22/2022] Open
Abstract
Bed rest leads to rapid impairments in glucose tolerance. Plasma volume and thus dilution space for glucose are also reduced with bed rest, but the potential influence on glucose tolerance has not been investigated. Accordingly, the aim was to investigate whether bed rest-induced impairments in glucose tolerance are related to a concomitant reduction in plasma volume. This hypothesis was tested mechanistically by restoring plasma volume with albumin infusion after bed rest and parallel determination of glucose tolerance. Fifteen healthy volunteers (age 24 ± 3 yr, body mass index 23 ± 2 kg/m2, maximal oxygen uptake 44 ± 8 ml·min-1·kg-1; means ± SD) completed 4 days of strict bed rest. Glucose tolerance [oral glucose tolerance test (OGTT)] and plasma and blood volumes (carbon monoxide rebreathing) were assessed before and after 3 days of bed rest. On the fourth day of bed rest, plasma volume was restored by means of an albumin infusion prior to an OGTT. Plasma volume was reduced by 9.9 ± 3.0% on bed rest day 3 and area under the curve for OGTT was augmented by 55 ± 67%. However, no association (R2 = 0.09, P = 0.33) between these simultaneously occurring responses was found. While normalization of plasma volume by matched albumin administration (408 ± 104 ml) transiently decreased (P < 0.05) resting plasma glucose concentration (5.0 ± 0.4 to 4.8 ± 0.3 mmol/l), this did not restore glucose tolerance. Bed rest-induced alterations in dilution space may influence resting glucose values but do not affect area under the curve for OGTT.
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Affiliation(s)
- S Dandanell
- Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| | - L Oberholzer
- Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| | - S Keiser
- Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| | - A B Andersen
- Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| | - T Haider
- Institute of Physiology, University of Zürich, Zurich, Switzerland; and
| | - M P Hilty
- Intensive Care Unit, University Hospital of Zürich, Zurich, Switzerland
| | | | - C Lundby
- Institute of Physiology, University of Zürich, Zurich, Switzerland; and
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