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Altherr C, Sietsema KE, Fulkerson Z. When the Powerhouse Is the Problem. Ann Am Thorac Soc 2024; 21:504-511. [PMID: 38426825 DOI: 10.1513/annalsats.202308-715cc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/08/2023] [Indexed: 03/02/2024] Open
Affiliation(s)
- Cody Altherr
- Clinical Research Core, Indiana Center for Musculoskeletal Health, and
| | - Kathy E Sietsema
- Division of Respiratory and Critical Care Physiology and Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
| | - Zachary Fulkerson
- Division of Pulmonary and Critical Care Medicine, Indiana University School of Medicine, Indianapolis, Indiana; and
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2
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El-Medany A, Adams ZH, Blythe HC, Hope KA, Kendrick AH, Abdala Sheikh AP, Paton JFR, Nightingale AK, Hart EC. Carotid body dysregulation contributes to Long COVID symptoms. COMMUNICATIONS MEDICINE 2024; 4:20. [PMID: 38374172 PMCID: PMC10876702 DOI: 10.1038/s43856-024-00447-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 01/31/2024] [Indexed: 02/21/2024] Open
Abstract
BACKGROUND The symptoms of long COVID, which include fatigue, breathlessness, dysregulated breathing, and exercise intolerance, have unknown mechanisms. These symptoms are also observed in heart failure and are partially driven by increased sensitivity of the carotid chemoreflex. As the carotid body has an abundance of ACE2 (the cell entry mechanism for SARS-CoV-2), we investigated whether carotid chemoreflex sensitivity was elevated in participants with long COVID. METHODS Non-hositalised participants with long-COVID (n = 14) and controls (n = 14) completed hypoxic ventilatory response (HVR; the measure of carotid chemoreflex sensitivity) and cardiopulmonary exercise tests. Parametric and normally distributed data were compared using Student's unpaired t-tests or ANOVA. Nonparametric equivalents were used where relevant. Peason's correlation coefficient was used to examine relationships between variables. RESULTS During cardiopulmonary exercise testing the VE/VCO2 slope (a measure of breathing efficiency) was higher in the long COVID group (37.8 ± 4.4) compared to controls (27.7 ± 4.8, P = 0.0003), indicating excessive hyperventilation. The HVR was increased in long COVID participants (-0.44 ± 0.23 l/min/ SpO2%, R2 = 0.77 ± 0.20) compared to controls (-0.17 ± 0.13 l/min/SpO2%, R2 = 0.54 ± 0.38, P = 0.0007). The HVR correlated with the VE/VCO2 slope (r = -0.53, P = 0.0036), suggesting that excessive hyperventilation may be related to carotid body hypersensitivity. CONCLUSIONS The carotid chemoreflex is sensitised in long COVID and may explain dysregulated breathing and exercise intolerance in these participants. Tempering carotid body excitability may be a viable treatment option for long COVID patients.
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Affiliation(s)
- Ahmed El-Medany
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Department of Cardiology, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
- Bristol Heart Institute, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Zoe H Adams
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Hazel C Blythe
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Katrina A Hope
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Department of Anaesthetics, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
| | - Adrian H Kendrick
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Department of Respiratory Medicine, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | | | - Julian F R Paton
- Manaaki Manawa, The Centre for Heart Research, University of Auckland, Auckland, New Zealand
| | - Angus K Nightingale
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Bristol Heart Institute, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Emma C Hart
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
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3
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Brawner CA, Lazar MH. Cardiopulmonary exercise testing criteria for advanced therapies in patients with heart failure. Heart Fail Rev 2023; 28:1297-1306. [PMID: 37644366 DOI: 10.1007/s10741-023-10337-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 08/31/2023]
Abstract
Many cardiology associations endorse the role of the cardiopulmonary exercise test (CPET) to define the severity of impairment of functional capacity in individuals with heart failure with reduced ejection fraction (HFrEF) and when evaluating the need for advanced therapies for these patients. The focus of the CPET within the cardiology community has been on peak volume of oxygen uptake (VO2). However, several CPET variables are associated with outcomes in individuals with and without chronic disease and can inform clinical decisions in individuals with HFrEF. In this manuscript, we will review the normal cardiopulmonary response to a graded exercise test and review current guideline recommendations relative to CPET in patients with HFrEF.
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Affiliation(s)
- Clinton A Brawner
- Division of Cardiovascular Medicine, Henry Ford Hospital, 6525 Second Ave., Detroit, MI, 48202, USA.
| | - Michael H Lazar
- Division of Pulmonary & Critical Care Medicine, Henry Ford Hospital, 2799 West Grand Blvd Suite K17, Detroit, MI, 48202, USA
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4
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Lehto T, Zetterman T, Markkula R, Arokoski J, Tikkanen H, Kalso E, Peltonen JE. Cardiac output and arteriovenous oxygen difference contribute to lower peak oxygen uptake in patients with fibromyalgia. BMC Musculoskelet Disord 2023; 24:541. [PMID: 37393269 DOI: 10.1186/s12891-023-06589-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 05/30/2023] [Indexed: 07/03/2023] Open
Abstract
BACKGROUND Patients with fibromyalgia (FM) exhibit low peak oxygen uptake ([Formula: see text]O2peak). We aimed to detect the contribution of cardiac output to ([Formula: see text]) and arteriovenous oxygen difference [Formula: see text] to [Formula: see text] from rest to peak exercise in patients with FM. METHODS Thirty-five women with FM, aged 23 to 65 years, and 23 healthy controls performed a step incremental cycle ergometer test until volitional fatigue. Alveolar gas exchange and pulmonary ventilation were measured breath-by-breath and adjusted for fat-free body mass (FFM) where appropriate. [Formula: see text] (impedance cardiography) was monitored. [Formula: see text] was calculated using Fick's equation. Linear regression slopes for oxygen cost (∆[Formula: see text]O2/∆work rate) and [Formula: see text] to [Formula: see text]O2 (∆[Formula: see text]/∆[Formula: see text]O2) were calculated. Normally distributed data were reported as mean ± SD and non-normal data as median [interquartile range]. RESULTS [Formula: see text]O2peak was lower in FM patients than in controls (22.2 ± 5.1 vs. 31.1 ± 7.9 mL∙min-1∙kg-1, P < 0.001; 35.7 ± 7.1 vs. 44.0 ± 8.6 mL∙min-1∙kg FFM-1, P < 0.001). [Formula: see text] and C(a-v)O2 were similar between groups at submaximal work rates, but peak [Formula: see text] (14.17 [13.34-16.03] vs. 16.06 [15.24-16.99] L∙min-1, P = 0.005) and C(a-v)O2 (11.6 ± 2.7 vs. 13.3 ± 3.1 mL O2∙100 mL blood-1, P = 0.031) were lower in the FM group. No significant group differences emerged in ∆[Formula: see text]O2/∆work rate (11.1 vs. 10.8 mL∙min-1∙W-1, P = 0.248) or ∆[Formula: see text]/∆[Formula: see text]O2 (6.58 vs. 5.75, P = 0.122) slopes. CONCLUSIONS Both [Formula: see text] and C(a-v)O2 contribute to lower [Formula: see text]O2peak in FM. The exercise responses were normal and not suggestive of a muscle metabolism pathology. TRIAL REGISTRATION ClinicalTrials.gov, NCT03300635. Registered 3 October 2017-Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT03300635 .
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Affiliation(s)
- Taneli Lehto
- Department of Sports and Exercise Medicine, Clinicum, University of Helsinki, Mäkelänkatu 47, Urhea-Hall, 00550, Helsinki, Finland.
- Department of Physical and Rehabilitation Medicine, Helsinki University Hospital and Helsinki University, Helsinki, Finland.
| | - Teemu Zetterman
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Pain Clinic, Helsinki University and Helsinki University Hospital, Helsinki, Finland
- City of Vantaa Health Centre, Vantaa, Finland
- Department of General Practice and Primary Health Care, University of Helsinki, Helsinki, Finland
| | - Ritva Markkula
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Pain Clinic, Helsinki University and Helsinki University Hospital, Helsinki, Finland
| | - Jari Arokoski
- Department of Physical and Rehabilitation Medicine, Helsinki University Hospital and Helsinki University, Helsinki, Finland
| | - Heikki Tikkanen
- Sports and Exercise Medicine, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Eija Kalso
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Pain Clinic, Helsinki University and Helsinki University Hospital, Helsinki, Finland
- SLEEPWELL Research Programme, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Juha E Peltonen
- Department of Sports and Exercise Medicine, Clinicum, University of Helsinki, Mäkelänkatu 47, Urhea-Hall, 00550, Helsinki, Finland
- Foundation for Sports and Exercise Medicine, Helsinki Sports and Exercise Medicine Clinic, Helsinki, Finland
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Ewert R, Elhadad MA, Habedank D, Heine A, Stubbe B. Primary mitochondrial disease as a rare cause of unclear breathlessness and distinctive performance degradation - a case report. BMC Pulm Med 2023; 23:104. [PMID: 36991405 DOI: 10.1186/s12890-023-02391-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/16/2023] [Indexed: 03/31/2023] Open
Abstract
BACKGROUND Primary muscular disorders (metabolic myopathies, including mitochondrial disorders) are a rare cause of dyspnea. We report a case of dyspnea caused by a mitochondrial disorder with a pattern of clinical findings that can be classified in the known pathologies of mitochondrial deletion syndrome. CASE PRESENTATION The patient presented to us at 29 years of age, having had tachycardia, dyspnea, and functional impairment since childhood. She had been diagnosed with bronchial asthma and mild left ventricular hypertrophy and treated accordingly, but her symptoms had worsened. After more than 20 years of progressive physical and social limitations was a mitochondrial disease suspected in the exercise testing. We performed cardiopulmonary exercise testing (CPET) with right heart catheterization showed typical signs of mitochondrial myopathy. Genetic testing confirmed the presence of a ~ 13 kb deletion in mitochondrial DNA from the muscle. The patient was treated with dietary supplements for 1 year. In the course of time, the patient gave birth to a healthy child, which is developing normally. CONCLUSION CPET and lung function data over 5 years demonstrated stable disease. We conclude that CPET and lung function analysis should be used consistently to evaluate the cause of dyspnea and for long-term observation.
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Affiliation(s)
- Ralf Ewert
- Department of Internal Medicine B, Pneumology, University Hospital Greifswald, F.-Sauerbruchstr, 17475, Greifswald, Germany
| | - Mohamed A Elhadad
- Department of Internal Medicine B, Pneumology, University Hospital Greifswald, F.-Sauerbruchstr, 17475, Greifswald, Germany
| | - Dirk Habedank
- Department of Internal Medicine B, Pneumology, University Hospital Greifswald, F.-Sauerbruchstr, 17475, Greifswald, Germany
- DRK-Hospital Berlin, Berlin, Germany
| | - Alexander Heine
- Department of Internal Medicine B, Pneumology, University Hospital Greifswald, F.-Sauerbruchstr, 17475, Greifswald, Germany
| | - Beate Stubbe
- Department of Internal Medicine B, Pneumology, University Hospital Greifswald, F.-Sauerbruchstr, 17475, Greifswald, Germany.
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Pathophysiology and Management of Fatigue in Neuromuscular Diseases. Int J Mol Sci 2023; 24:ijms24055005. [PMID: 36902435 PMCID: PMC10003182 DOI: 10.3390/ijms24055005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/24/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Fatigue is a major determinant of quality of life and motor function in patients affected by several neuromuscular diseases, each of them characterized by a peculiar physiopathology and the involvement of numerous interplaying factors. This narrative review aims to provide an overview on the pathophysiology of fatigue at a biochemical and molecular level with regard to muscular dystrophies, metabolic myopathies, and primary mitochondrial disorders with a focus on mitochondrial myopathies and spinal muscular atrophy, which, although fulfilling the definition of rare diseases, as a group represent a representative ensemble of neuromuscular disorders that the neurologist may encounter in clinical practice. The current use of clinical and instrumental tools for fatigue assessment, and their significance, is discussed. A summary of therapeutic approaches to address fatigue, encompassing pharmacological treatment and physical exercise, is also overviewed.
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Onofrei CD, Gottschall EB, Zell‐Baran L, Rose CS, Kraus R, Pang K, Krefft SD. Unexplained dyspnea linked to mitochondrial myopathy following military deployment to Southwest Asia and Afghanistan. Physiol Rep 2023; 11:e15520. [PMID: 36695704 PMCID: PMC9875744 DOI: 10.14814/phy2.15520] [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: 07/29/2022] [Revised: 10/29/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023] Open
Abstract
We identified a case of probable mitochondrial myopathy (MM) in a soldier with dyspnea and reduced exercise tolerance through cardiopulmonary exercise testing (CPET) following Southwest Asia (SWA) deployment. Muscle biopsy showed myopathic features. We compared demographic, occupational exposure, and clinical characteristics in symptomatic military deployers with and without probable MM diagnosed by CPET criteria. We evaluated 235 symptomatic military personnel who deployed to SWA and/or Afghanistan between 2010 and 2021. Of these, 168 underwent cycle ergometer maximal CPET with an indwelling arterial line. We defined probable MM based on five CPET criteria: arterial peak exercise lactate >12 mEq/L, anaerobic threshold (AT) ≤50%, maximum oxygen consumption (VO2max ) <95% predicted, oxygen (O2) pulse percent predicted (pp) at least 10% lower than heart rate pp, and elevated ventilatory equivalent for O2 at end exercise (VE/VO2 ≥ 40). We characterized demographics, smoking status/pack-years, spirometry, and deployment exposures, and used descriptive statistics to compare findings in those with and without probable MM. We found 9/168 (5.4%) deployers with probable MM. Compared to symptomatic deployers without probable MM, they were younger (p = 0.0025) and had lower mean BMI (p = 0.02). They had a higher mean forced expiratory volume (FEV1)pp (p = 0.02) and mean arterial oxygen partial pressure (PaO2) at maximum exercise (p = 0.0003). We found no significant differences in smoking status, deployment frequency/duration, or inhalational exposures. Our findings suggest that mitochondrial myopathy may be a cause of dyspnea and reduced exercise tolerance in a subset of previously deployed military personnel. CPET with arterial line may assist with MM diagnosis and management.
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Affiliation(s)
- Claudia Daniela Onofrei
- Division of Pulmonary and Critical Care Medicine, Department of MedicineNational Jewish HealthDenverColoradoUSA
| | - Eva Brigitte Gottschall
- Division of Environmental and Occupational Health Sciences, Department of MedicineNational Jewish HealthDenverColoradoUSA
- Division of Pulmonary and Critical Care Medicine, Department of MedicineUniversity of Colorado Anschutz Medical CampusColoradoAuroraUSA
- Department of Environmental and Occupational HealthColorado School of Public HealthColoradoAuroraUSA
| | - Lauren Zell‐Baran
- Division of Environmental and Occupational Health Sciences, Department of MedicineNational Jewish HealthDenverColoradoUSA
- Department of Environmental and Occupational HealthColorado School of Public HealthColoradoAuroraUSA
| | - Cecile Stephanie Rose
- Division of Environmental and Occupational Health Sciences, Department of MedicineNational Jewish HealthDenverColoradoUSA
- Division of Pulmonary and Critical Care Medicine, Department of MedicineUniversity of Colorado Anschutz Medical CampusColoradoAuroraUSA
- Department of Environmental and Occupational HealthColorado School of Public HealthColoradoAuroraUSA
| | - Richard Kraus
- Division of Environmental and Occupational Health Sciences, Department of MedicineNational Jewish HealthDenverColoradoUSA
| | - Kathy Pang
- Division of Environmental and Occupational Health Sciences, Department of MedicineNational Jewish HealthDenverColoradoUSA
| | - Silpa Dhoma Krefft
- Division of Environmental and Occupational Health Sciences, Department of MedicineNational Jewish HealthDenverColoradoUSA
- Division of Pulmonary and Critical Care Medicine, Department of MedicineUniversity of Colorado Anschutz Medical CampusColoradoAuroraUSA
- Department of Environmental and Occupational HealthColorado School of Public HealthColoradoAuroraUSA
- Division of Pulmonary and Critical Care Medicine, Department of MedicineVeterans Administration Eastern Colorado Health Care SystemColoradoAuroraUSA
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8
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Leem JH, Jeon HE, Nam H, Kim HC, Joa KL. A 2-day cardiopulmonary exercise test in chronic fatigue syndrome patients who were exposed to humidifier disinfectants. Environ Anal Health Toxicol 2022; 37:e2022033-0. [PMID: 36916046 PMCID: PMC10014750 DOI: 10.5620/eaht.2022033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022] Open
Abstract
Some survivors of humidifier disinfectants (HDs) complain of chronic, inexplicable fatigue, and post-exertional malaise (PEM). Two-day cardiopulmonary exercise tests (CPETs) performed 24 hours apart (2-day CPET protocol) are increasingly employed to evaluate PEM and related disabilities among individuals with chronic fatigue syndrome (CFS). The purpose of this study was to assess the reproducibility of CPET variables in individuals who had been exposed to HD and to show that 2-day CPET is an objective means of differentiating between fatigue conditions in people with CFS symptoms who have been exposed to HDs. Twenty-nine HD survivors with CFS symptoms were enrolled in this study. To document and assess PEM in CFS, a 2-day CPET was conducted to measure baseline functional capacity (CPET1) and provoke PEM. Twenty-four hours later, a second CPET assessed changes in related variables, focusing on PEM effects on functional capacity. This CPET also measured changes in energy production and physiological function, objectively documenting PEM effects. In the 2-day CPET, the peak oxygen consumption (VO2peak), VO2 at ventilatory threshold (VO2@VT), time to reach VO2peak, and time to reach VO2@VT were significantly decreased (p<0.001). The peak O2 pulse and O2 pulse at VT also decreased significantly (p<0.001). A 6-minute walk test revealed significantly decreased distance (p<0.01). This is the first study to conduct a 2-day consecutive CPET in previously exposed HD participants with CFS symptoms. Our results confirm previous work that demonstrated abnormal responses to PEM in CFS patients. Therefore, a 2-day CPET is an objective measure to differentiate fatigue conditions in people with CFS symptoms who have been exposed to HDs.
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Affiliation(s)
- Jong-Han Leem
- Department of Occupational and Environmental Medicine, College of Medicine, Inha University, Incheon, Republic of Korea
| | - Hyoung-Eun Jeon
- Department of Physical & Rehabilitation Medicine, College of Medicine, Inha University, Incheon, Republic of Korea
| | - Hun Nam
- Department of Physical & Rehabilitation Medicine, College of Medicine, Inha University, Incheon, Republic of Korea
| | - Hwan-Cheol Kim
- Department of Occupational and Environmental Medicine, College of Medicine, Inha University, Incheon, Republic of Korea
| | - Kyung-Lim Joa
- Department of Physical & Rehabilitation Medicine, College of Medicine, Inha University, Incheon, Republic of Korea
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9
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Mart MF, Ely EW, Tolle JJ, Patel MB, Brummel NE. Physiologic responses to exercise in survivors of critical illness: an exploratory pilot study. Intensive Care Med Exp 2022; 10:35. [PMID: 36008625 PMCID: PMC9410741 DOI: 10.1186/s40635-022-00461-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/10/2022] [Indexed: 11/29/2022] Open
Abstract
Background ICU survivors suffer from impaired physical function and reduced exercise capacity, yet the underlying mechanisms are poorly understood. The goal of this exploratory pilot study was to investigate potential mechanisms of exercise limitation using cardiopulmonary exercise testing (CPET) and 6-min walk testing (6MWT). Methods We enrolled adults aged 18 years or older who were treated for respiratory failure or shock in medical, surgical, or trauma ICUs at Vanderbilt University Medical Center (Nashville, TN, United States). We excluded patients with pre-existing cardiac dysfunction, a contraindication to CPET, or the need for supplemental oxygen at rest. We performed CPET and 6MWT 6 months after ICU discharge. We measured standard CPET parameters in addition to two measures of oxygen utilization during exercise (VO2-work rate slope and VO2 recovery half-time). Results We recruited 14 participants. Low exercise capacity (i.e., VO2Peak < 80% predicted) was present in 11 out of 14 (79%) with a median VO2Peak of 12.6 ml/kg/min [9.6–15.1] and 6MWT distance of 294 m [240–433]. In addition to low VO2Peak, CPET findings in survivors included low oxygen uptake efficiency slope, low oxygen pulse, elevated chronotropic index, low VO2-work rate slope, and prolonged VO2 recovery half-time, indicating impaired oxygen utilization with a hyperdynamic heart rate and ventilatory response, a pattern seen in non-critically ill patients with mitochondrial myopathies. Worse VO2-work rate slope and VO2 recovery half-time were strongly correlated with worse VO2Peak and 6MWT distance, suggesting that exercise capacity was potentially limited by impaired muscle oxygen utilization. Conclusions These exploratory data suggest ICU survivors may suffer from impaired muscular oxygen metabolism due to mitochondrial dysfunction that impairs exercise capacity long-term. These findings should be further characterized in future studies that include direct assessments of muscle mitochondrial function in ICU survivors.
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Affiliation(s)
- Matthew F Mart
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, T1218 Medical Center North, Nashville, TN, 37232, USA. .,Critical Illness, Brain Dysfunction, and Survivorship (CIBS) Center, Vanderbilt University Medical Center, Nashville, TN, USA. .,Geriatric Research, Education, and Clinical Center (GRECC), Tennessee Valley Healthcare System, Nashville, TN, USA.
| | - E Wesley Ely
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, T1218 Medical Center North, Nashville, TN, 37232, USA.,Critical Illness, Brain Dysfunction, and Survivorship (CIBS) Center, Vanderbilt University Medical Center, Nashville, TN, USA.,Geriatric Research, Education, and Clinical Center (GRECC), Tennessee Valley Healthcare System, Nashville, TN, USA
| | - James J Tolle
- Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, T1218 Medical Center North, Nashville, TN, 37232, USA
| | - Mayur B Patel
- Critical Illness, Brain Dysfunction, and Survivorship (CIBS) Center, Vanderbilt University Medical Center, Nashville, TN, USA.,Geriatric Research, Education, and Clinical Center (GRECC), Tennessee Valley Healthcare System, Nashville, TN, USA.,Division of Acute Care Surgery, Department of Surgery, Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nathan E Brummel
- Critical Illness, Brain Dysfunction, and Survivorship (CIBS) Center, Vanderbilt University Medical Center, Nashville, TN, USA.,Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, The Ohio State University College of Medicine, Columbus, OH, USA.,Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
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10
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Rodriguez JC, Peterman JE, Fleenor BS, Whaley MH, Kaminsky LA, Harber MP. Cardiopulmonary Exercise Responses in Individuals with Metabolic Syndrome: The Ball State Adult Fitness Longitudinal Lifestyle Study. Metab Syndr Relat Disord 2022; 20:414-420. [DOI: 10.1089/met.2021.0130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Julio C. Rodriguez
- Clinical Exercise Physiology, Human Performance Laboratory, Ball State University, Muncie, Indiana, USA
| | - James E. Peterman
- Fisher Institute of Health and Well-Being, Ball State University, Muncie, Indiana, USA
| | - Bradley S. Fleenor
- Clinical Exercise Physiology, Human Performance Laboratory, Ball State University, Muncie, Indiana, USA
| | - Mitchell H. Whaley
- Clinical Exercise Physiology, Human Performance Laboratory, Ball State University, Muncie, Indiana, USA
| | - Leonard A. Kaminsky
- Fisher Institute of Health and Well-Being, Ball State University, Muncie, Indiana, USA
| | - Matthew P. Harber
- Clinical Exercise Physiology, Human Performance Laboratory, Ball State University, Muncie, Indiana, USA
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11
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Biomarkers of Redox Balance Adjusted to Exercise Intensity as a Useful Tool to Identify Patients at Risk of Muscle Disease through Exercise Test. Nutrients 2022; 14:nu14091886. [PMID: 35565853 PMCID: PMC9105000 DOI: 10.3390/nu14091886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 02/01/2023] Open
Abstract
The screening of skeletal muscle diseases constitutes an unresolved challenge. Currently, exercise tests or plasmatic tests alone have shown limited performance in the screening of subjects with an increased risk of muscle oxidative metabolism impairment. Intensity-adjusted energy substrate levels of lactate (La), pyruvate (Pyr), β-hydroxybutyrate (BOH) and acetoacetate (AA) during a cardiopulmonary exercise test (CPET) could constitute alternative valid biomarkers to select “at-risk” patients, requiring the gold-standard diagnosis procedure through muscle biopsy. Thus, we aimed to test: (1) the validity of the V’O2-adjusted La, Pyr, BOH and AA during a CPET for the assessment of the muscle oxidative metabolism (exercise and mitochondrial respiration parameters); and (2) the discriminative value of the V’O2-adjusted energy and redox markers, as well as five other V’O2-adjusted TCA cycle-related metabolites, between healthy subjects, subjects with muscle complaints and muscle disease patients. Two hundred and thirty subjects with muscle complaints without diagnosis, nine patients with a diagnosed muscle disease and ten healthy subjects performed a CPET with blood assessments at rest, at the estimated 1st ventilatory threshold and at the maximal intensity. Twelve subjects with muscle complaints presenting a severe alteration of their profile underwent a muscle biopsy. The V’O2-adjusted plasma levels of La, Pyr, BOH and AA, and their respective ratios showed significant correlations with functional and muscle fiber mitochondrial respiration parameters. Differences in exercise V’O2-adjusted La/Pyr, BOH, AA and BOH/AA were observed between healthy subjects, subjects with muscle complaints without diagnosis and muscle disease patients. The energy substrate and redox blood profile of complaining subjects with severe exercise intolerance matched the blood profile of muscle disease patients. Adding five tricarboxylic acid cycle intermediates did not improve the discriminative value of the intensity-adjusted energy and redox markers. The V’O2-adjusted La, Pyr, BOH, AA and their respective ratios constitute valid muscle biomarkers that reveal similar blunted adaptations in muscle disease patients and in subjects with muscle complaints and severe exercise intolerance. A targeted metabolomic approach to improve the screening of “at-risk” patients is discussed.
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12
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Abstract
Mitochondrial diseases (MD) include an heterogenous group of systemic disorders caused by sporadic or inherited mutations in nuclear or mitochondrial DNA (mtDNA), causing impairment of oxidative phosphorylation system. Hypertrophic cardiomyopathy is the dominant pattern of cardiomyopathy in all forms of mtDNA disease, being observed in almost 40% of the patients. Dilated cardiomyopathy, left ventricular noncompaction, and conduction system disturbances have been also reported. In this article, the authors discuss the current clinical knowledge on MD, focusing on diagnosis and management of mitochondrial diseases caused by mtDNA mutations.
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Cardiopulmonary Exercise Test Parameters in Athletic Population: A Review. J Clin Med 2021; 10:jcm10215073. [PMID: 34768593 PMCID: PMC8584629 DOI: 10.3390/jcm10215073] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/17/2021] [Accepted: 10/26/2021] [Indexed: 11/23/2022] Open
Abstract
Although still underutilized, cardiopulmonary exercise testing (CPET) allows the most accurate and reproducible measurement of cardiorespiratory fitness and performance in athletes. It provides functional physiologic indices which are key variables in the assessment of athletes in different disciplines. CPET is valuable in clinical and physiological investigation of individuals with loss of performance or minor symptoms that might indicate subclinical cardiovascular, pulmonary or musculoskeletal disorders. Highly trained athletes have improved CPET values, so having just normal values may hide a medical disorder. In the present review, applications of CPET in athletes with special attention on physiological parameters such as VO2max, ventilatory thresholds, oxygen pulse, and ventilatory equivalent for oxygen and exercise economy in the assessment of athletic performance are discussed. The role of CPET in the evaluation of possible latent diseases and overtraining syndrome, as well as CPET-based exercise prescription, are outlined.
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Bhatia R, Cohen BH, L McNinch N. A novel exercise testing algorithm to diagnose mitochondrial myopathy. Muscle Nerve 2021; 63:715-723. [PMID: 33533527 DOI: 10.1002/mus.27191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 01/25/2021] [Accepted: 01/31/2021] [Indexed: 11/09/2022]
Abstract
INTRODUCTION Oxygen uptake efficiency slope (OUES) is a noninvasive cardiopulmonary exercise testing (CPET) measurement based on oxygen uptake (V˙O2 ) and minute ventilation (V˙E) and is a marker of the efficiency of oxygen utilization by the body. However, it has not been studied in mitochondrial disorders. We explored noninvasive CPET parameters, including OUES, as a way to reliably diagnose mitochondrial myopathy. METHODS We performed cycle ergometer maximal exercise testing on definite and suspected mitochondrial myopathy subjects (MM-D and MM-S) and their age- and sex-matched controls. OUES was corrected for body surface area (OUES/BSA) to eliminate the effect of body size. RESULTS A total of 40 participants, including 20 MM-D (n = 13; 6 males; aged 14-64 years) and 7 MM-S (5 males, aged 11-30 years) subjects and 20 controls, completed the study. MM-D subjects showed lower aerobic fitness than controls. OUES/BSA was lower in MM-D subjects, suggesting inefficient oxygen utilization. Area under the curve (AUC) and 95% confidence interval (CI) for OUES/BSA (AUC, 0.91; 95% CI, 0.80-1.00), peak V˙O2 percent predicted (AUC, 0.95; 95% CI, 0.86-1.00), and V˙O2 /work slope (AUC, 0.94; 95% CI, 0.85-1.00) showed excellent ability to diagnose mitochondrial myopathy in MM-D subjects. We applied a diagnostic approach based on the parameters just noted to MM-S subjects and their controls and were able to support or disprove the diagnosis of mitochondrial myopathy. DISCUSSION We proposed and applied an approach based on the aformentioned three CPET parameters to diagnose mitochondrial myopathy reliably and found it to be clinically useful.
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Affiliation(s)
- Rajeev Bhatia
- Department of Pediatrics, Division of Pulmonology, Akron Children's Hospital, Akron, Ohio
| | - Bruce H Cohen
- Department of Pediatrics, Neurodevelopmental Science Center-Division of Neurology, Akron Children's Hospital, Akron, Ohio.,Northeast Ohio Medical University, Rootstown, Ohio
| | - Neil L McNinch
- Rebecca D Considine Research Institute, Akron Children's Hospital, Akron, Ohio
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Abstract
Metabolic myopathies are muscle disorders caused by a biochemical defect of the skeletal muscle energy system resulting in exercise intolerance. The primary aim of this research was to evaluate the oxygen cost (∆V’O2/∆Work-Rate) during incremental exercise in patients with metabolic myopathies as compared with patients with non-metabolic myalgia and healthy subjects. The study groups consisted of eight patients with muscle glycogenoses (one Tarui and seven McArdle diseases), seven patients with a complete and twenty-two patients with a partial myoadenylate deaminase (MAD) deficiency in muscle biopsy, five patients with a respiratory chain deficiency, seventy-three patients with exercise intolerance and normal muscle biopsy (non-metabolic myalgia), and twenty-eight healthy controls. The subjects underwent a cardiopulmonary exercise test (CPX Medgraphics) performed on a bicycle ergometer. Pulmonary V’O2 was measured breath-by-breath throughout the incremental test. The ∆V’O2/∆Work-Rate slope for exercise was determined by linear regression analysis. Lower oxygen consumption (peak percent of predicted, mean ± SD; p < 0.04, one-way ANOVA) was seen in patients with glycogenoses (62.8 ± 10.2%) and respiratory chain defects (70.8 ± 23.3%) compared to patients with non-metabolic myalgia (100.0 ± 15.9%) and control subjects (106.4 ± 23.5%). ∆V’O2/∆Work-Rate slope (mLO2.min−1.W−1) was increased in patients with MAD absent (12.6 ± 1.5), MAD decreased (11.3 ± 1.1), glycogenoses (14.0 ± 2.5), respiratory chain defects (13.1 ± 1.2), and patients with non-metabolic myalgia (11.3 ± 1.3) compared with control subjects (10.2 ± 0.7; p < 0.001, one-way ANOVA). In conclusion, patients with metabolic myopathies display an increased oxygen cost during exercise and therefore can perform less work for a given VO2 consumption during daily life-submaximal exercises.
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Porcelli S, Grassi B, Poole DC, Marzorati M. Exercise intolerance in patients with mitochondrial myopathies: perfusive and diffusive limitations in the O2 pathway. CURRENT OPINION IN PHYSIOLOGY 2019. [DOI: 10.1016/j.cophys.2019.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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17
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Abstract
Metabolic myopathies are a heterogeneous group of disorders characterized by inherited defects of enzymatic pathways involved in muscle cellular energetics and adenosine triphosphate synthesis. Skeletal and respiratory muscles are most affected. There are multiple mechanisms of disease. The age of onset and prognosis vary. Metabolic myopathies cause exercise intolerance, myalgia, and increase in muscle breakdown products during exercise. Some affect smooth muscle like the diaphragm and cause respiratory failure. The pathophysiology is complex and the evidence in literature to guide diagnosis and management is sparse. Treatment is limited. This review discusses the pathophysiology and diagnostic evaluation of these disorders.
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Affiliation(s)
- Patrick Koo
- Department of Respiratory, Critical Care, and Sleep Medicine, University of Tennessee College of Medicine Chattanooga, Erlanger Health System, 975 East 3rd Street, C-735, Chattanooga, TN 37403, USA.
| | - Jigme M Sethi
- Department of Respiratory, Critical Care, and Sleep Medicine, University of Tennessee College of Medicine Chattanooga, Erlanger Health System, 975 East 3rd Street, C-735, Chattanooga, TN 37403, USA
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Muraresku CC, McCormick EM, Falk MJ. Mitochondrial Disease: Advances in clinical diagnosis, management, therapeutic development, and preventative strategies. CURRENT GENETIC MEDICINE REPORTS 2018; 6:62-72. [PMID: 30393588 PMCID: PMC6208355 DOI: 10.1007/s40142-018-0138-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE OF REVIEW Primary mitochondrial disease encompasses an impressive range of inherited energy deficiency disorders having highly variable molecular etiologies as well as clinical onset, severity, progression, and response to therapies of multi-system manifestations. Significant progress has been made in primary mitochondrial disease diagnostic approaches, clinical management, therapeutic options, and preventative strategies that are tailored to major mitochondrial disease phenotypes and subclasses. RECENT FINDINGS The extensive phenotypic pleiotropy of individual mitochondrial diseases from an organ-based perspective is reviewed. Improved consensus on standards for mitochondrial disease patient care are being complemented by emerging therapies that target specific molecular subtypes of mitochondrial disease. Reproductive counseling options now include preimplantation genetic diagnosis at the time of in vitro fertilization for familial mutations in nuclear genes and some mtDNA disorders. Mitochondrial replacement technologies have promise for some mtDNA disorders, although practical and societal challenges remain to allow their further research analyses and clinical utilization. SUMMARY A dramatic increase has occurred in recent years in the recognition, understanding, treatment options, and preventative strategies for primary mitochondrial disease.
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Affiliation(s)
- Colleen C. Muraresku
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Elizabeth M. McCormick
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Marni J. Falk
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
- Department of Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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