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Caswell AM, Tripp TR, Kontro H, Edgett BA, Wiley JP, Lun V, MacInnis MJ. The influence of sex, hemoglobin mass, and skeletal muscle characteristics on cycling critical power. J Appl Physiol (1985) 2024; 137:10-22. [PMID: 38779761 DOI: 10.1152/japplphysiol.00120.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/29/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
Critical power (CP) represents an important threshold for exercise performance and fatiguability. We sought to determine the extent to which sex, hemoglobin mass (Hbmass), and skeletal muscle characteristics influence CP. Before CP determination (i.e., 3-5 constant work rate trials to task failure), Hbmass and skeletal muscle oxidative capacity (τ) were measured and vastus lateralis (VL) muscle biopsy samples were collected from 12 females and 12 males matched for aerobic fitness relative to fat-free mass (FFM) [means (SD); V̇o2max: 59.2 (7.7) vs. 59.5 (7.1) mL·kg·FFM-1·min-1, respectively]. Males had a significantly greater CP than females in absolute units [225 (28) vs. 170 (43) W; P = 0.001] but not relative to body mass [3.0 (0.6) vs. 2.7 (0.6) W·kg·BM-1; P = 0.267] or FFM [3.6 (0.7) vs. 3.7 (0.8) W·kg·FFM-1; P = 0.622]. Males had significantly greater W' (P ≤ 0.030) and greater Hbmass (P ≤ 0.016) than females, regardless of the normalization approach; however, there were no differences in mitochondrial protein content (P = 0.375), τ (P = 0.603), or MHC I proportionality (P = 0.574) between males and females. Whether it was expressed in absolute or relative units, CP was positively correlated with Hbmass (0.444 ≤ r ≤ 0.695; P < 0.05), mitochondrial protein content (0.413 ≤ r ≤ 0.708; P < 0.05), and MHC I proportionality (0.506 ≤ r ≤ 0.585; P < 0.05), and negatively correlated with τ when expressed in relative units only (-0.588 ≤ r ≤ -0.527; P < 0.05). Overall, CP was independent of sex, but variability in CP was related to Hbmass and skeletal muscle characteristics. The extent to which manipulations in these physiological parameters influence CP warrants further investigation to better understand the factors underpinning CP.NEW & NOTEWORTHY In males and females matched for aerobic fitness [maximal oxygen uptake normalized to fat-free mass (FFM)], absolute critical power (CP) was greater in males, but relative CP (per kilogram body mass or FFM) was similar between sexes. CP correlated with hemoglobin mass, mitochondrial protein content, myosin heavy chain type I proportion, and skeletal muscle oxidative capacity. These findings demonstrate the importance of matching sexes for aerobic fitness, but further experiments are needed to determine causality.
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Affiliation(s)
- Allison M Caswell
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Thomas R Tripp
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Hilkka Kontro
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Brittany A Edgett
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - J Preston Wiley
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Victor Lun
- Sport Medicine Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Martin J MacInnis
- Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
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Breenfeldt Andersen A, Bonne TC, Nordsborg NB, Holm-Sørensen H, Bejder J. Duplicate measures of hemoglobin mass within an hour: feasibility, reliability, and comparison of three devices in supine position. Scand J Clin Lab Invest 2024; 84:1-10. [PMID: 38265850 DOI: 10.1080/00365513.2024.2303711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 12/17/2023] [Indexed: 01/25/2024]
Abstract
Duplicate measure of hemoglobin mass by carbon monoxide (CO)-rebreathing is a logistical challenge as recommendations prompt several hours between measures to minimize CO-accumulation. This study investigated the feasibility and reliability of performing duplicate CO-rebreathing procedures immediately following one another. Additionally, it was evaluated whether the obtained hemoglobin mass from three different CO-rebreathing devices is comparable. Fifty-five healthy participants (22 males, 23 females) performed 222 duplicate CO-rebreathing procedures in total. Additionally, in a randomized cross-over design 10 participants completed three experimental trials, each including three CO-rebreathing procedures, with the first and second separated by 24 h and the second and third separated by 5-10 min. Each trial was separated by >48 h and conducted using either a glass-spirometer, a semi-automated electromechanical device, or a standard three-way plastic valve designed for pulmonary measurements. Hemoglobin mass was 3 ± 22 g lower (p < 0.05) at the second measure when performed immediately after the first with a typical error of 1.1%. Carboxyhemoglobin levels reached 10.9 ± 1.3%. In the randomized trial, hemoglobin mass was similar between the glass-spirometer and three-way valve, but ∼6% (∼50 g) higher for the semi-automated device. Notably, differences in hemoglobin mass were up to ∼13% (∼100 g) when device-specific recommendations for correction of CO loss to myoglobin and exhalation was followed. In conclusion, it is feasible and reliable to perform two immediate CO-rebreathing procedures. Hemoglobin mass is comparable between the glass-spirometer and the three-way plastic valve, but higher for the semi-automated device. The differences are amplified if the device-specific recommendations of CO-loss corrections are followed.
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Affiliation(s)
| | - Thomas Christian Bonne
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
| | | | - Henrik Holm-Sørensen
- Department of Anaesthesiology, Centre for Cancer and Organ Diseases, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Bejder
- Department of Nutrition, Exercise and Sports (NEXS), University of Copenhagen, Copenhagen, Denmark
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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] [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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Vinje V, Bomholt T, Lundby C, Oturai P, Rix M, Lindhard K, Hornum M. Intravascular volumes and the influence on anemia assessed by a carbon monoxide rebreathing method in patients undergoing maintenance hemodialysis. Hemodial Int 2024; 28:40-50. [PMID: 37827985 DOI: 10.1111/hdi.13118] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/14/2023]
Abstract
INTRODUCTION Fluid overload is a major challenge in hemodialysis patients and might cause hypervolemia. We speculated that hemodialysis patients reaching dry weight could have undetected hypervolemia and low hemoglobin (Hb) concentration (g/dL) due to hemodilution. METHODS The study included hemodialysis patients (n = 22) and matched healthy controls (n = 22). Blood volume, plasma volume, red blood cell volume, and total Hb mass were determined using a carbon monoxide (CO)-rebreathing method in hemodialysis patients reaching dry weight and controls. Blood volume measurements were also obtained by a dual-isotope labeling technique in a subgroup for validation purposes. FINDINGS In the hemodialysis group, the median specific blood volume was 89.3 mL/kg (interquartile range [IQR]: 76.7-95.4 mL/kg) and was higher than in the control group (79.9 mL/kg [IQR: 70.4-88.0 mL/kg]; p < 0.037). The median specific plasma volume was 54.7 mL/kg (IQR: 47.1-61.0 mL/kg) and 44.0 mL/kg (IQR: 38.7-49.5 mL/kg) in the hemodialysis and control groups, respectively (p < 0.001). Hb concentration was lower in hemodialysis patients (p < 0.001), whereas no difference in total Hb mass was observed between groups (p = 0.11). A correlation was found between blood volume measured by the CO-rebreathing test and the dual-isotope labeling technique in the control group (r = 0.83, p = 0.015), but not the hemodialysis group (r = 0.25, p = 0.60). DISCUSSION The hemodialysis group had increased specific blood volume at dry weight due to high plasma volume, suggesting a hypervolemic state. However, correlation was not established against the dual-isotope labeling technique underlining that the precision of the CO-rebreathing test should be further validated. The total Hb mass was similar between hemodialysis patients and controls, unlike Hb concentration, which emphasizes that Hb concentration is an inaccurate marker of anemia among hemodialysis patients.
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Affiliation(s)
- Vårin Vinje
- Department of Nephrology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Tobias Bomholt
- Department of Nephrology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Carsten Lundby
- Centre for Physical Activity Research, Rigshospitalet, Copenhagen, Denmark
- Section for Health and Exercise Physiology, Faculty of Social and Health Sciences, Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - Peter Oturai
- Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, Copenhagen, Denmark
| | - Marianne Rix
- Department of Nephrology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Kristine Lindhard
- Department of Nephrology, Herlev Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Mads Hornum
- Department of Nephrology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Lundby C. Comment by Schmidt and Byrnes based on erroneous assumptions. Scand J Clin Lab Invest 2023; 83:356-357. [PMID: 37452604 DOI: 10.1080/00365513.2023.2233078] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 06/29/2023] [Accepted: 07/02/2023] [Indexed: 07/18/2023]
Affiliation(s)
- Carsten Lundby
- Section for Health and Exercise Physiology, Inland Norway University of Applied Sciences, Lillehammer, Norway
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Kellenberger K, Steiner T, Wehrlin JP. Comparison of the automatised and the optimised carbon monoxide rebreathing methods. Scandinavian Journal of Clinical and Laboratory Investigation 2022; 82:474-480. [PMID: 36129418 DOI: 10.1080/00365513.2022.2122078] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Recently, a new automated carbon monoxide (CO) rebreathing method (aCO) to estimate haemoglobin mass (Hbmass) was introduced. The aCO method uses the same CO dilution principle as the widely used optimised CO rebreathing method (oCO). The two methods differ in terms of CO administration, body position, and rebreathing time. Whereas with aCO, CO is administered automatically by the system in a supine position of the subject, with oCO, CO is administered manually by an experienced operator with the subject sitting. Therefore, the aim of this study was to quantify possible differences in Hbmass estimated with the two methods. Hbmass was estimated in 18 subjects (9 females, 9 males) with oCO using capillary blood samples (oCOc) and aCO taking simultaneously venous blood samples (aCOv) and capillary blood samples (aCOc). Overall, Hbmass was different between the three measurement procedures (F = 57.55, p < .001). Hbmass was lower (p < .001) for oCOc (737 g ± 179 g) than for both aCOv (825 g ± 189 g, -9.3%) and aCOc (835 g ± 189 g, -10.6%). There was no difference in Hbmass estimated with aCOv and aCOc procedures (p = .12). Three factors can likely explain the 10% difference in Hbmass: differences in calculations (including a factor for myoglobin flux), body position (distribution of CO in blood circulation) during rebreathing, and time of blood sampling. Moreover, the determination of Hbmass with aCO is possible with capillary blood sampling instead of venous blood sampling.
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Affiliation(s)
- Katja Kellenberger
- Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland
| | - Thomas Steiner
- Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland
| | - Jon Peter Wehrlin
- Section for Elite Sport, Swiss Federal Institute of Sport, Magglingen, Switzerland
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7
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Kontro H, Bertagnolli C, Murias JM, MacInnis MJ. Impairment in maximal lactate steady state after carbon monoxide inhalation is related to training status. Exp Physiol 2022; 107:1265-1282. [PMID: 36029041 DOI: 10.1113/ep090642] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/17/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? What is the effect of an elevated COHb concentration following carbon monoxide inhalation on the maximal lactate steady state (MLSS) in humans and is this effect dependent on aerobic fitness? What is the main finding and its importance? An elevated COHb concentration intensified physiological responses to exercise at the MLSS- including heart rate, ventilation, and peripheral fatigue-in all participants and reduced the MLSS (i.e., destabilized the blood lactate concentration) in trained but not untrained males and females. ABSTRACT This study investigated whether a lower effective [Hb], induced by carbon monoxide (CO) inhalation, reduces the peak oxygen uptake (V̇O2 peak) and the maximal lactate steady state (MLSS) and whether training status explains individual variation in these impairments. Healthy young participants completed two ramp incremental tests (n = 20 [10 female]) and two trials at MLSS (n = 16 [8 female]) following CO rebreathe tests and sham procedures (SHAM) in random orders. All fitness variables were normalized to fat-free mass (FFM) to account for sex-related differences in body composition, and males and females were matched for aerobic fitness. The V̇O2 peak (mean [SD]: -4.2 [3.7]%), peak power output (-3.3 [2.2]%), and respiratory compensation point (-6.3 [4.5]%) were reduced in CO compared with SHAM (P < 0.001 for all), but the gas exchange threshold (-3.3 [7.1]%) was not (P = 0.077). Decreases in V̇O2 peak (r = -0.45; P = 0.047) and peak power output (r = -0.49; P = 0.029) in CO were correlated with baseline aerobic fitness. Compared to SHAM, physiological and perceptual indicators of exercise-related stress were exacerbated by CO while cycling at MLSS. Notably, the mean blood lactate concentration ([La]) increased (i.e., Δ[La] > 1.0 mM) between 10 min (5.5 [1.4] mM) and 30 min (6.8 [1.3] mM; P = 0.026) in CO, with 9/16 participants classified as unstable. These unstable participants had a higher V̇O2 peak (66.2 [8.5] vs. 56.4 [8.8] mL·kg FFM-1 ·min-1 , P = 0.042) and V̇O2 at MLSS (55.8 vs. 44.3 mL·kg FFM-1 ·min-1 , P = 0.006) compared to the stable group. In conclusion, a reduced O2 -carrying capacity decreased maximal and submaximal exercise performance, with higher aerobic fitness associated with greater impairments in both. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Hilkka Kontro
- Faculty of Kinesiology, Human Performance Lab, University of Calgary, Canada
| | - Craig Bertagnolli
- Faculty of Kinesiology, Human Performance Lab, University of Calgary, Canada
| | - Juan M Murias
- Faculty of Kinesiology, Human Performance Lab, University of Calgary, Canada
| | - Martin J MacInnis
- Faculty of Kinesiology, Human Performance Lab, University of Calgary, Canada
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Sex Differences in Orthostatic Tolerance Are Mainly Explained by Blood Volume and Oxygen Carrying Capacity. Crit Care Explor 2022; 4:e0608. [PMID: 35018347 PMCID: PMC8735745 DOI: 10.1097/cce.0000000000000608] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Supplemental Digital Content is available in the text. The reduced orthostatic tolerance (OT) that is characteristic of the female sex may be explained by multiple phenotypic differences between sexes. This study aimed to elucidate the mechanistic role of blood volume (BV) and oxygen carrying capacity on sex differences in OT.
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Parsons IT, Snape D, O'Hara J, Holdsworth DA, Stacey MJ, Gall N, Chowienczyk P, Wainwright B, Woods DR. Echocardiographic changes following active heat acclimation. J Therm Biol 2020; 93:102705. [PMID: 33077126 PMCID: PMC7467033 DOI: 10.1016/j.jtherbio.2020.102705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/19/2020] [Accepted: 08/21/2020] [Indexed: 11/26/2022]
Abstract
Heat adaption through acclimatisation or acclimation improves cardiovascular stability by maintaining cardiac output due to compensatory increases in stroke volume. The main aim of this study was to assess whether 2D transthoracic echocardiography (TTE) could be used to confirm differences in resting echocardiographic parameters, before and after active heat acclimation (HA). Thirteen male endurance trained cyclists underwent a resting blinded TTE before and after randomisation to either 5 consecutive daily exertional heat exposures of controlled hyperthermia at 32°C with 70% relative humidity (RH) (HOT) or 5-days of exercise in temperate (21°C with 36% RH) environmental conditions (TEMP). Measures of HA included heart rate, gastrointestinal temperature, skin temperature, sweat loss, total non-urinary fluid loss (TNUFL), plasma volume and participant's ratings of perceived exertion (RPE). Following HA, the HOT group demonstrated increased sweat loss (p = 0.01) and TNUFL (p = 0.01) in comparison to the TEMP group with a significantly decreased RPE (p = 0.01). On TTE, post exposure, there was a significant comparative increase in the HOT group in left ventricular end diastolic volume (p = 0.029), SV (p = 0.009), left atrial volume (p = 0.005), inferior vena cava diameter (p = 0.041), and a significant difference in mean peak diastolic mitral annular velocity (e’) (p = 0.044). Cardiovascular adaptations to HA appear to be predominantly mediated by improvements in increased preload and ventricular compliance. TTE is a useful tool to demonstrate and quantify cardiac HA. There are echocardiographic differences in comparing an isothermic heat acclimation regime to equivalent temperate exercise. Heat acclimation results in an increased LA volume, LVEDV, stroke volume, IVC diameter and LV diastolic function (e’). The increase in LA volume and IVC diameter would suggest an increase in preload secondary to increased plasma volume. The rise in the speed of early LV relaxation (e’) during diastole reflects increased LV compliance or reduced LV stiffness. This gives further insight into the cardiovascular adaptations to heat acclimation.
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Affiliation(s)
- Iain T Parsons
- Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, UK; School of Cardiovascular Medicine and Sciences, King's College London, UK.
| | - Daniel Snape
- Research Institute for Sport, Physical Activity and Leisure, Carnegie School of Sport, Leeds Beckett University, UK.
| | - John O'Hara
- Research Institute for Sport, Physical Activity and Leisure, Carnegie School of Sport, Leeds Beckett University, UK.
| | - David A Holdsworth
- Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, UK.
| | - Michael J Stacey
- Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, UK.
| | - Nick Gall
- School of Cardiovascular Medicine and Sciences, King's College London, UK.
| | - Phil Chowienczyk
- School of Cardiovascular Medicine and Sciences, King's College London, UK.
| | - Barney Wainwright
- Research Institute for Sport, Physical Activity and Leisure, Carnegie School of Sport, Leeds Beckett University, UK.
| | - David R Woods
- Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, UK; Research Institute for Sport, Physical Activity and Leisure, Carnegie School of Sport, Leeds Beckett University, UK.
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Rønnestad BR, Hamarsland H, Hansen J, Holen E, Montero D, Whist JE, Lundby C. Five weeks of heat training increases haemoglobin mass in elite cyclists. Exp Physiol 2020; 106:316-327. [DOI: 10.1113/ep088544] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/18/2020] [Indexed: 11/08/2022]
Affiliation(s)
| | | | - Joar Hansen
- Innland University of Applied Sciences Lillehammer Norway
| | - Espen Holen
- Innland University of Applied Sciences Lillehammer Norway
| | - David Montero
- Faculty of Kinesiology Cumming School of Medicine University of Calgary Calgary Canada
| | | | - Carsten Lundby
- Innland University of Applied Sciences Lillehammer Norway
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Bomholt T, Larsson S, Rix M, Rytter S, Feldt‐Rasmussen B, Hornum M, Lundby C. Intravascular volumes evaluated by a carbon monoxide rebreathing method in patients undergoing chronic hemodialysis. Hemodial Int 2020; 24:252-260. [DOI: 10.1111/hdi.12820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 01/08/2020] [Accepted: 01/20/2020] [Indexed: 02/02/2023]
Affiliation(s)
- Tobias Bomholt
- Department of Nephrology, RigshospitaletUniversity of Copenhagen Copenhagen Denmark
| | - Sara Larsson
- Department of Nephrology, RigshospitaletUniversity of Copenhagen Copenhagen Denmark
| | - Marianne Rix
- Department of Nephrology, RigshospitaletUniversity of Copenhagen Copenhagen Denmark
| | - Sarah Rytter
- Department of Nephrology, RigshospitaletUniversity of Copenhagen Copenhagen Denmark
| | - Bo Feldt‐Rasmussen
- Department of Nephrology, RigshospitaletUniversity of Copenhagen Copenhagen Denmark
- Faculty of Health and Medical Sciences, Department of Clinical MedicineUniversity of Copenhagen Copenhagen Denmark
| | - Mads Hornum
- Department of Nephrology, RigshospitaletUniversity of Copenhagen Copenhagen Denmark
- Faculty of Health and Medical Sciences, Department of Clinical MedicineUniversity of Copenhagen Copenhagen Denmark
| | - Carsten Lundby
- Centre for Physical Activity Research, Rigshospitalet Copenhagen Denmark
- Inland Norway University of Applied Sciences Lillehammer Norway
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12
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Diaz-Canestro C, Haider T, Lundby C, Montero D. Relationship between plasma volume and essential blood constituents in patients with heart failure and preserved ejection fraction. Clin Physiol Funct Imaging 2019; 40:131-138. [PMID: 31823430 DOI: 10.1111/cpf.12614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 12/04/2019] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Notwithstanding recent progress on molecular mechanisms underlying heart failure with preserved ejection fraction (HFpEF), multiple pathophysiological aspects of this condition including the basis of anaemia and other haematological disorders remain unresolved. In this study, we sought to determine the relationship of plasma volume (PV), a plausible confounding factor for the concentration of solutes in blood, with key haematological markers in HFpEF patients. METHODS Total circulating PV was determined with high precision, automated carbon monoxide rebreathing in 24 stable HFpEF patients (70 ± 8 years, left ventricular ejection fraction = 55±5%) and 18 healthy age- and sex-matched control (HC) individuals. Linear regression analyses were performed to determine the association of PV with a comprehensive set of haematological variables. RESULTS Haematocrit (40·1 ± 4·9 versus 43·6 ± 2·7%, P = 0·004) and haemoglobin concentration (131 ± 16 versus 142 ± 7 g l-1 , P = 0·003) were reduced in HFpEF patients compared with HC individuals. In regression analyses, PV was negatively associated with haematocrit (r = -0·45, P = 0·029) and haemoglobin concentration (r = -0·44, P = 0·030) in HFpEF patients, whereas these variables were not associated with PV in HC individuals (P≥0·198). Regarding blood electrolytes, PV was negatively associated with K+ (r = -0·43, P = 0·036) and Ca2+ (r = -0·44, P = 0·032) in HFpEF patients but not in HC individuals (P≥0·734). None of the above associations were detected in HFpEF patients when using ideal instead of measured PV. CONCLUSION The blood concentration of routine markers of anaemia and electrolyte balance is specifically and linearly associated with PV in HFpEF patients. Excess or deficit of circulating PV may confound clinical diagnosis in this population.
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Affiliation(s)
- Candela Diaz-Canestro
- Faculty of Kinesiology, Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - Thomas Haider
- University Heart Center, University Hospital Zurich, Zurich, Switzerland
| | - Carsten Lundby
- Inland Norway University of Applied Sciences, Lillehammer, Norway
| | - David Montero
- Faculty of Kinesiology, Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
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Effects of hemodialysis on blood volume, macro- and microvascular function. Microvasc Res 2019; 129:103958. [PMID: 31734376 DOI: 10.1016/j.mvr.2019.103958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Vascular dysfunction is considered to spur the progression of cardiovascular disease in hemodialysis (HD) patients. Whether the HD procedure itself contributes to vascular dysfunction remains incompletely investigated. The present study sought to comprehensively assess the effects of HD on arterial and venous function along with concomitant changes in blood volume (BV). METHODS AND RESULTS We determined BV with high-precision, automated carbon monoxide-rebreathing, arterial stiffness using applanation tonometry and intrinsic microvascular function via retinal vessel analysis prior to and after conventional 4-hour HD in fasting-controlled conditions in 10 patients. All HD patients were non-smokers and non-obese (body mass index = 22.8 ± 2.8 m·kg-2). Hypertension (70%), coronary artery disease (40%) and diabetes mellitus (20%) were the most prevalent comorbidities. Prior to HD, all patients presented with hypervolemia (+2208 ± 1213 ml). HD decreased body weight (-1.72 ± 1.25 kg, P = 0.002) and plasma volume (-689 ± 566 ml, P = 0.004), while hematocrit (Hct) was concomitantly increased (+4.8 ± 4.5%, P = 0.009). HD did not affect large elastic artery stiffness, as determined by carotid-femoral pulse wave velocity (P = 0.448) and carotid distensibility (P = 0.562). In contrast, flicker light-induced retinal venular dilation was reduced by three-fourths after HD (-2.4 ± 1.7%, P = 0.039), in parallel to increased retinal venular diameter (+11.2 ± 4.9 μm, P = 0.002). In regression analyses, a negative association was observed between HD-induced changes in Hct and retinal venular dilation (r ≥ -0.89, P ≤ 0.045). CONCLUSION Conventional HD resulting in substantial plasma volume removal do not alter large artery elastic properties, whereas intrinsic microvascular venular dilator function is markedly impaired, an effect directly associated with the increase in hemoconcentration.
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Lundby C, Ponte B, Lundby A, Robach P, de Seigneux S. Red blood cell volume is not decreased in ESA-naive anemic chronic kidney disease patients. Physiol Rep 2018; 6:e13900. [PMID: 30426716 PMCID: PMC6234145 DOI: 10.14814/phy2.13900] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 09/27/2018] [Indexed: 11/24/2022] Open
Abstract
Anemia is defined according to decreased blood hemoglobin concentration ([Hb]), which is considered a marker of low total red blood cell volume (RBCV). Alterations of plasma volume (PV) may also modify [Hb] without concomitant changes in RBCV. Since anemia and fluid retention are frequent complications of chronic kidney disease (CKD), we hypothesized that anemia during CKD may in part be related to expanded PV without a simultaneous decrease in RBCV. We quantified hemoglobin mass, RBCV, PV, and total blood volume (BV) using an automated carbon monoxide device in 40 consecutive stage 3-5 CKD patients not on dialysis and in seven healthy male controls of the same age range. These were compared within and to predicted volumes according to Nadler's formula. Arterial stiffness and NT-proBNP were measured. RBCV was similar to predicted values range in anemic CKD patients 2073 (1818-2704) versus, 2061 (1725-2473) mL, P > 0.05. In contrast, PV was largely increased in anemic CKD patients (3881 (3212-4352) vs. 2916 (2851-3201)), P = 0.01. Of 26 anemic patients, only six had a >20% decrease in RBCV as the cause for their anemia, whereas 14 had a >20% increase of PV as a cause for their anemia. NT-pro BNP correlated with eGFR but neither with PV nor BV, whereas arterial stiffness was not correlated to blood volumes. Anemia in CKD as diagnosed by low [Hb] is not necessarily associated to low RBCV but may reflect increased PV. This finding has implications for the treatment of CKD patients and may refrain from normalizing [Hb] levels in all CKD patients.
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Affiliation(s)
- Carsten Lundby
- Department of Clinical MedicineRigshospitalet ‐ FinsencentretKøbenhavnDenmark
| | - Belen Ponte
- Service and Laboratory of NephrologyDepartment of Internal Medicine Specialties and PHYME DepartmentUniversity Hospital of GenevaGenevaSwitzerland
| | | | - Paul Robach
- Ecole Nationale des Sports de Montagne, site de l'Ecole Nationale de Ski et d'alpinismeChamonixFrance
| | - Sophie de Seigneux
- Service and Laboratory of NephrologyDepartment of Internal Medicine Specialties and PHYME DepartmentUniversity Hospital of GenevaGenevaSwitzerland
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Plumb JOM, Kumar S, Otto J, Schmidt W, Richards T, Montgomery HE, Grocott MPW. Replicating measurements of total hemoglobin mass (tHb-mass) within a single day: precision of measurement; feasibility and safety of using oxygen to expedite carbon monoxide clearance. Physiol Rep 2018; 6:e13829. [PMID: 30203465 PMCID: PMC6131726 DOI: 10.14814/phy2.13829] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 07/21/2018] [Indexed: 11/24/2022] Open
Abstract
Hemoglobin concentration ([Hb]) is a function of total hemoglobin mass (tHb-mass) and plasma volume. [Hb] may fall by dilution due to plasma volume expansion and changes in the perioperative period may therefore correlate poorly with blood loss. A simple, reliable, repeatable way to measure plasma volume and tHb-mass would have substantial clinical utility. The "optimized carbon monoxide re-breathing method" (oCOR) meets these criteria. However, it is recommended that a minimum of 12 h (when breathing room air) is left between repeat measurements. Twenty-four subjects underwent 3 days of testing. Two oCOR tests were performed (T1 and T2), 3 h apart, with a different CO clearance method employed between tests aiming to keep the carboxyhemoglobin level below 10%. The primary aim was to ascertain whether tHb-mass testing could be safely repeated within 3 h if carboxyhemoglobin levels were actively reduced by breathing supplemental oxygen (PROCA ). Secondary aims were to compare two other clearance methods; moderate exercise (PROCB ), or a combination of the two (PROCC ). Finally, the reliability of the oCOR method was assessed. Mean (SD) tHb-mass was 807.9 ± (189.7 g) (for T1 on day 1). PROCA lowered the carboxyhemoglobin level from the end of T1 (mean 6.64%) to the start of T2 (mean 2.95%) by a mean absolute value of 3.69%. For PROCB and PROCC the mean absolute decreases in carboxyhemoglobin were 4.00% and 4.31%, respectively. The fall in carboxyhemoglobin between T1 and T2 was greatest in PROCC ; this was statistically significantly lower than that of PROCA (P = 0.0039) and PROCB (P = 0.0289). The test-retest reliability for the measurement of total hemoglobin mass was good with a mean typical error (TE) of 2.0%. The oCOR method is safe and can be repeated within 3 h when carbon monoxide is suitably cleared between tests. Using oxygen therapy alone adequately achieves this.
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Affiliation(s)
- James O. M. Plumb
- Respiratory and Critical Care Research AreaNIHR Biomedical Research CentreUniversity Hospital Southampton NHS Foundation TrustUniversity of SouthamptonSouthamptonUnited Kingdom
- Centre for Human Integrative PhysiologyFaculty of MedicineUniversity of SouthamptonSouthamptonUnited Kingdom
- Anaesthesia and Critical Care Research UnitUniversity Hospital Southampton NHSFTSouthamptonUnited Kingdom
- Shackleton Department of AnaesthesiaUniversity Hospital Southampton NHSFTSouthamptonUnited Kingdom
| | - Shriya Kumar
- Anaesthesia and Critical Care Research UnitUniversity Hospital Southampton NHSFTSouthamptonUnited Kingdom
- University of Southampton Medical SchoolSouthamptonUnited Kingdom
| | - James Otto
- Shackleton Department of AnaesthesiaUniversity Hospital Southampton NHSFTSouthamptonUnited Kingdom
- Division of Surgery and Interventional ScienceUniversity College LondonLondonUnited Kingdom
| | - Walter Schmidt
- Department of Sports Medicine/Sports PhysiologyUniversity of BayreuthBayreuthGermany
| | - Toby Richards
- Division of Surgery and Interventional ScienceUniversity College LondonLondonUnited Kingdom
| | - Hugh E. Montgomery
- Centre for Human Health and PerformanceInstitute of Sport, Exercise and HealthUniversity College LondonNIHR University College London Hospitals Biomedical Research CentreLondonUnited Kingdom
| | - Mike P. W. Grocott
- Respiratory and Critical Care Research AreaNIHR Biomedical Research CentreUniversity Hospital Southampton NHS Foundation TrustUniversity of SouthamptonSouthamptonUnited Kingdom
- Centre for Human Integrative PhysiologyFaculty of MedicineUniversity of SouthamptonSouthamptonUnited Kingdom
- Anaesthesia and Critical Care Research UnitUniversity Hospital Southampton NHSFTSouthamptonUnited Kingdom
- Shackleton Department of AnaesthesiaUniversity Hospital Southampton NHSFTSouthamptonUnited Kingdom
- Department of AnesthesiologyDuke University School of MedicineDurhamNorth Carolina
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Siebenmann C, Keiser S, Robach P, Lundby C. CORP: The assessment of total hemoglobin mass by carbon monoxide rebreathing. J Appl Physiol (1985) 2017; 123:645-654. [DOI: 10.1152/japplphysiol.00185.2017] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/14/2017] [Accepted: 06/26/2017] [Indexed: 11/22/2022] Open
Abstract
In this Cores of Reproducibility in Physiology (CORP) article, we present the theory and practical aspects of the carbon monoxide (CO) rebreathing method for the determination of total hemoglobin mass in humans. With CO rebreathing, a small quantity of CO is diluted in O2and rebreathed for a specified time period, during which most of the CO is absorbed and bound to circulating hemoglobin. The dilution principle then allows calculation of the total number of circulating hemoglobin molecules based on the number of absorbed CO molecules and the resulting changes in the fraction of carboxyhemoglobin in blood. Total hemoglobin mass is derived by multiplication with the molar weight of hemoglobin. CO rebreathing has been used for >100 yr and has undergone steady improvement so that today excellent values in terms of accuracy and precision can be achieved if the methodological precautions are carefully followed.
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Affiliation(s)
- Christoph Siebenmann
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Stefanie Keiser
- Center for Integrative Human Physiology, Institute of Physiology, University of Zürich, Zürich, Switzerland; and
| | - Paul Robach
- National School for Mountain Sports, Site of the National School for Skiing and Mountaineering (ENSA), Chamonix, France
| | - Carsten Lundby
- The Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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