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Karaa A, Johnson N, Clarkson I, Newman W, Dorenbaum A, Cohen BH. Characterization of Fatigue in Primary Mitochondrial Myopathies: Findings From a Qualitative Interview Study. Neurol Clin Pract 2024; 14:e200229. [PMID: 38229875 PMCID: PMC10790285 DOI: 10.1212/cpj.0000000000200229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 11/04/2023] [Indexed: 01/18/2024]
Abstract
Background and Objectives Primary mitochondrial myopathies are genetic disorders that primarily affect peripheral skeletal muscles. Patients with primary mitochondrial myopathies often experience muscle weakness, fatigue, and other significant impacts on health-related quality of life. The aim of this noninterventional qualitative study was to collect the most bothersome fatigue-related symptoms and impacts reported by patients with primary mitochondrial myopathies and determine whether the questions included in an existing patient-reported outcome measure, the Modified Fatigue Impact Scale, are relevant and interpretable for this population. Methods The interviews contained a concept elicitation exercise to understand the most bothersome primary mitochondrial myopathies symptoms and impacts and a cognitive debriefing section to review the questions included in the Modified Fatigue Impact Scale for relevance and interpretability. Transcripts were coded using ATLAS.ti software. Results Interviews were conducted with 16 patients who were aged 16 years and older with a genetically confirmed and clinical diagnosis of symptomatic primary mitochondrial myopathies. Concept elicitation interviews established that while patients with mitochondrial myopathies reported a wide variety of symptoms and impacts, one of the most impactful symptoms discussed was fatigue. Cognitive debriefing interview results confirmed that the Modified Fatigue Impact Scale items were relevant, were interpretable, and largely captured patients' experience with fatigue. Discussion Fatigue was one of the most widely discussed experiences discussed by participants and was considered the most important symptom/impact to treat by most of the participants. The Modified Fatigue Impact Scale could be used in future clinical trials to measure treatment benefit in fatigue-related impacts.
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Affiliation(s)
- Amel Karaa
- Division of Genetics (AK), Massachusetts General Hospital, Pediatric Department, Harvard Medical School; Endpoint Outcomes (NJ, IC), Boston, MA; Reneo Pharmaceuticals, Inc (WN, AD), San Diego, CA; and Akron Children's Hospital (BHC), Department of Pediatrics and Integrative Medical Sciences, Northeast Ohio Medical University
| | - Nathan Johnson
- Division of Genetics (AK), Massachusetts General Hospital, Pediatric Department, Harvard Medical School; Endpoint Outcomes (NJ, IC), Boston, MA; Reneo Pharmaceuticals, Inc (WN, AD), San Diego, CA; and Akron Children's Hospital (BHC), Department of Pediatrics and Integrative Medical Sciences, Northeast Ohio Medical University
| | - Ian Clarkson
- Division of Genetics (AK), Massachusetts General Hospital, Pediatric Department, Harvard Medical School; Endpoint Outcomes (NJ, IC), Boston, MA; Reneo Pharmaceuticals, Inc (WN, AD), San Diego, CA; and Akron Children's Hospital (BHC), Department of Pediatrics and Integrative Medical Sciences, Northeast Ohio Medical University
| | - Wendy Newman
- Division of Genetics (AK), Massachusetts General Hospital, Pediatric Department, Harvard Medical School; Endpoint Outcomes (NJ, IC), Boston, MA; Reneo Pharmaceuticals, Inc (WN, AD), San Diego, CA; and Akron Children's Hospital (BHC), Department of Pediatrics and Integrative Medical Sciences, Northeast Ohio Medical University
| | - Alejandro Dorenbaum
- Division of Genetics (AK), Massachusetts General Hospital, Pediatric Department, Harvard Medical School; Endpoint Outcomes (NJ, IC), Boston, MA; Reneo Pharmaceuticals, Inc (WN, AD), San Diego, CA; and Akron Children's Hospital (BHC), Department of Pediatrics and Integrative Medical Sciences, Northeast Ohio Medical University
| | - Bruce H Cohen
- Division of Genetics (AK), Massachusetts General Hospital, Pediatric Department, Harvard Medical School; Endpoint Outcomes (NJ, IC), Boston, MA; Reneo Pharmaceuticals, Inc (WN, AD), San Diego, CA; and Akron Children's Hospital (BHC), Department of Pediatrics and Integrative Medical Sciences, Northeast Ohio Medical University
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Pechstein AE, Gollie JM, Keyser RE, Guccione AA. Walking Endurance and Oxygen Uptake On-Kinetics in Individuals With Parkinson Disease Following Overground Locomotor Training. J Neurol Phys Ther 2023; 47:99-111. [PMID: 36538418 DOI: 10.1097/npt.0000000000000423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND PURPOSE Poor walking endurance in Parkinson disease (PD) may be attributable to both bioenergetic and biomechanical factors, but locomotor training methods addressing both these factors simultaneously are understudied. Our objective was to examine the effects of overground locomotor training (OLT) on walking endurance in individuals with mild-to-moderate PD, and to further explore potential cardiorespiratory contributions. METHODS A single-arm, longitudinal design was used to examine the effects of 24 biweekly sessions of OLT in people with mild-to-moderate PD (n = 12). Walking endurance was measured as total distance walked during a 10-minute walk test (10minWT). Oxygen uptake (V˙ o2 ) on-kinetic profiles were determined using a monoexponential function. Perceived fatigability was assessed following the 10minWT using a self-report scale. Magnitude of change in primary outcomes was assessed using Cohen's d and adjusted for sample size (Cohen's d(unbiased) ). RESULTS Participants executed 3036 (297) steps and maintained 65.5% (8%) age-predicted heart rate maximum in a typical session lasting 56.9 (2.5) minutes. Medium effects in total distance walked-885.9 (157.2) versus 969.5 (140.9); Cohen's d(unbiased) = 0.54-and phase II time constant of the V˙ o2 on-kinetic profile-33.7 (12.3) versus 25.9 (15.3); Cohen's d(unbiased) = 0.54-were observed alongside trivial effects for perceived fatigability-4.7 (1.4) versus 4.8 (1.5); Cohen's d(unbiased) = 0.11-following OLT. DISCUSSION AND CONCLUSIONS These preliminary findings may demonstrate the potential for moderate-intensity OLT to improve walking endurance and enhance cardiorespiratory adjustments to walking activity in adults with mild-to-moderate PD.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A407 ).
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Affiliation(s)
- Andrew E Pechstein
- Department of Rehabilitation Science, George Mason University, Fairfax, Virginia (A.E.P., J.M.G., R.E.K., A.A.G.); Department of Physical Therapy, University of Delaware, Newark (A.E.P.); and Research Service, Veterans Affairs Medical Center, Washington, District of Columbia (J.M.G.)
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3
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Fujita D, Kubo Y. The reliability of VO 2 kinetics during a 6-minute walking test is influenced by walk speed. J Phys Ther Sci 2021; 33:876-879. [PMID: 34873366 PMCID: PMC8636911 DOI: 10.1589/jpts.33.876] [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: 07/13/2021] [Accepted: 09/08/2021] [Indexed: 11/24/2022] Open
Abstract
[Purpose] This study aimed to investigate the reliability of time constant measurements
of oxygen intake at fast and comfortable speeds during a 6-min waling test. [Participants
and Methods] The study included 10 healthy young males who walked at 4.5 km/h and 6.0 km/h
twice for 6 min each in speed treadmill. Breath-by-breath gas exchange data were
continuously measured and used to calculate the time constant of oxygen uptake. The
reproducibility and variability of the variables were verified using the limit of
agreement, inter-class correlation coefficient, coefficient of variation, and standard
error of measurement. [Results] The limit of agreement was −8.5 to 2.3 s and −3.9 to 2.1 s
for speeds 4.5 km/h and 6.0 km/h, respectively. The inter-class correlation coefficient,
coefficient of variation, and standard error of measurement of the time constant for both
speeds were 0.52 and 0.83, 11.2% and 6.4%, and 5.3 s and 1.8 s, respectively. [Conclusion]
The results of this study suggested that the cardiopulmonary response, in terms of oxygen
uptake, was more consistent during fast walking than during comfortable walking in a 6-min
walking test with constant speed.
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Affiliation(s)
- Daisuke Fujita
- Department of Physical Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare: 3-6-40 Momochihama, Sawara-ku, Fukuoka city, Fukuoka 814-0001, Japan
| | - Yuusuke Kubo
- Department of Rehabilitation, Kobori Orthopaedic Clinic, Japan
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Combret Y, Medrinal C, Prieur G, Robledo Quesada A, Gillot T, Gravier FE, Bonnevie T, Lamia B, Le Roux P, Reychler G. Oxygen uptake kinetics during treadmill walking in adolescents with clinically stable cystic fibrosis. Physiother Theory Pract 2021; 38:1389-1397. [PMID: 33390080 DOI: 10.1080/09593985.2020.1868029] [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] [Indexed: 12/14/2022]
Abstract
Background: Oxygen uptake (V̇O2) kinetics have been shown to be slowed in adolescents with cystic fibrosis (CF) during heavy-intensity cycling and maximal exercise testing.Objectives: This study investigated V̇O2 kinetics in adolescents with CF compared to control adolescents (CON) during a treadmill-walking exercise.Methods: Eight adolescents with CF and mild-to-moderate pulmonary obstruction (5 girls; 13.1 ± 2.5 years; FEV1 67.8 ± 21.4%) and 18 CON adolescents (10 girls; 13.8 ± 1.8 years) were recruited. Pulmonary gas exchange and ventilation were measured during a single transition of 10 min of treadmill walking and a 5 min seated recovery period. Participant's walking speed was determined during a one-minute self-paced walking task along a 50-m corridor. A six-parameter, non-linear regression model was used to describe the changes in V̇O2 function during the treadmill walking and recovery, with monoexponential curve fitting used to describe the mean response time (MRT1) at the onset of exercise, and the half-life (T1/2V̇O2) at the offset of exercise. V̇O2 baseline and amplitude, minute ventilation and respiratory equivalents were recorded.Results: V̇O2 kinetics were slower in CF group compared to CON group during the treadmill walking with a greater MRT1 (32 ± 14 s vs 21 ± 16 s; p = .04, effect size = 0.75). The T1/2V̇O2 was prolonged during recovery in CF group compared to CON group (86 ± 24 s vs 56 ± 22 s; p = .04, effect size = 1.31). The mean VE/V̇CO2 during exercise was the only parameter significantly greater in CF group compared to CON group (32.9 ± 2.3 vs 29.0 ± 2.4; p < .01, effect size = 1.66). Conclusion: V̇O2 kinetics were found to be slowed in adolescents with CF during treadmill walking.
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Affiliation(s)
- Yann Combret
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium
| | - Clément Medrinal
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Erphan, Paris-Saclay University, UVSQ, Versailles, France.,Saint Michel School of Physiotherapy, Paris, France
| | - Guillaume Prieur
- Physiotherapy Department, Le Havre Hospital, Montivilliers, France.,Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium.,UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France
| | | | - Timothée Gillot
- Cetaps, EA3832, Rouen University, Mont Saint Aignan, France.,School of Physiotherapy, Rouen University Hospital, Rouen, France
| | - Francis-Edouard Gravier
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,ADIR Association, Rouen University Hospital, Bois-Guillaume, France
| | - Tristan Bonnevie
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,ADIR Association, Rouen University Hospital, Bois-Guillaume, France
| | - Bouchra Lamia
- UPRES EA3830 - GRHV, Normandie University, UNIROUEN, Institute for Research and Innovation in Biomedicine (IRIB), Rouen, France.,Pulmonology Department, Le Havre Hospital, Montivilliers, France.,Intensive Care Unit, Respiratory Department, Rouen University Hospital, Rouen, France
| | - Pascal Le Roux
- Pediatric Department, Le Havre Hospital, Montivilliers, France
| | - Grégory Reychler
- Institut De Recherche Et d'Expérimentation Clinique (IREC), Pôle De Pneumologie, ORL and Dermatologie, Université Catholique De Louvain, Brussels, Belgium.,Department of Physical Medicine and Rehabilitation, Saint-Luc University Clinics, Brussels, Belgium
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5
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Frailty and Physical Fitness in Elderly People: A Systematic Review and Meta-analysis. Sports Med 2020; 51:143-160. [DOI: 10.1007/s40279-020-01361-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Ribeiro JAM, Oliveira AGDS, Thommazo-Luporini LD, Monteiro CI, Ocamoto GN, Catai AM, Borghi-Silva A, Phillips SA, Russo TL. Underlying mechanisms of oxygen uptake kinetics in chronic post-stroke individuals: A correlational, cross-sectional pilot study. PLoS One 2020; 15:e0241872. [PMID: 33166347 PMCID: PMC7652273 DOI: 10.1371/journal.pone.0241872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/21/2020] [Indexed: 11/30/2022] Open
Abstract
Post-stroke individuals presented deleterious changes in skeletal muscle and in the cardiovascular system, which are related to reduced oxygen uptake ([Formula: see text]) and take longer to produce energy from oxygen-dependent sources at the onset of exercise (mean response time, MTRON) and during post-exercise recovery (MRTOFF). However, to the best of our knowledge, no previous study has investigated the potential mechanisms related to [Formula: see text] kinetics response (MRTON and MRTOFF) in post-stroke populations. The main objective of this study was to determine whether the MTRON and MRTOFF are related to: 1) body composition; 2) arterial compliance; 3) endothelial function; and 4) hematological and inflammatory profiles in chronic post-stroke individuals. Data on oxygen uptake ([Formula: see text]) were collected using a portable metabolic system (Oxycon Mobile®) during the six-minute walk test (6MWT). The time to achieve 63% of [Formula: see text] during a steady state (MTRON) and recovery (MRTOFF) were analyzed by the monoexponential model and corrected by a work rate (wMRTON and wMRTOFF) during 6MWT. Correlation analyses were made using Spearman's rank correlation coefficient (rs) and the bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals. Twenty-four post-stroke participants who were physically inactive took part in the study. The wMRTOFF was correlated with the following: skeletal muscle mass (rs = -0.46), skeletal muscle mass index (rs = -0.45), augmentation index (rs = 0.44), augmentation index normalized to a heart rate of 75 bpm (rs = 0.64), reflection magnitude (rs = 0.43), erythrocyte (rs = -0.61), hemoglobin (rs = -0.54), hematocrit (rs = -0.52) and high-sensitivity C-reactive protein (rs = 0.58), all p < 0.05. A greater amount of oxygen uptake during post-walking recovery is partially related to lower skeletal muscle mass, greater arterial stiffness, reduced number of erythrocytes and higher systemic inflammation in post-stroke individuals.
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Affiliation(s)
| | | | | | | | | | - Aparecida Maria Catai
- Department of Physical Therapy, Federal University of São Carlos, São Carlos, Brazil
| | - Audrey Borghi-Silva
- Department of Physical Therapy, Federal University of São Carlos, São Carlos, Brazil
| | - Shane A. Phillips
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Thiago Luiz Russo
- Department of Physical Therapy, Federal University of São Carlos, São Carlos, Brazil
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7
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Camargo PF, Ditomaso-Luporini L, de Carvalho LCS, Goulart CDL, Sebold R, Dos Santos PB, Roscani MG, Borghi-Silva A. Association Between the Predictors of Functional Capacity and Heart Rate Off-Kinetics in Patients with Chronic Obstructive Pulmonary Disease. Int J Chron Obstruct Pulmon Dis 2020; 15:1977-1986. [PMID: 32884254 PMCID: PMC7438181 DOI: 10.2147/copd.s260284] [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: 04/28/2020] [Accepted: 07/21/2020] [Indexed: 01/10/2023] Open
Abstract
Background The heart rate (HR) kinetics as well as other predictors of functional capacity such as the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test (CAT), the Duke Activity Status Index (DASI) and the handgrip strength (HGS) represent important tools in assessing the impact of COPD on exercise performance and health status of individuals with COPD. Purpose To verify the relationship between functional capacity, measured using the six-minute walking test (6MWT), with the HR off-kinetics, HGS and the DASI and CAT scores. Methods For this cross-sectional study, 29 subjects with COPD underwent body composition, pulmonary function and cardiac function tests. Subsequently, the DASI and CAT questionnaires and HGS test were performed. The beat-to-beat R-R intervals (IRR) were collected in rest, during the test and in recovery after the 6MWT. The HR off-kinetics was obtained during a 360-second period in post-exercise recovery through the HR mono-exponential decay. Results Moderate correlations were observed between: 1) walked distance (WD) in the 6MWT and the CAT and DASI scores (r= −0.58, p=0.001 and r= 0.58, p=0.001, respectively); 2) WD and HGS (r=0.37, p=0.05); 3) and WD and HR off-kinetics (τ; r= −0.54, p=0.002 and MRT; r= −0.55, p=0.002, respectively). Conclusion The 6MWT performance is a direct measurement to evaluate functional capacity. Additionally, it is related to other direct and indirect markers for functional evaluation in patients with COPD. These results suggest the application of these tools in clinical practice, based on the accessibility, non-invasive character and easy applicability of these methods.
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Affiliation(s)
- Patrícia Faria Camargo
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Luciana Ditomaso-Luporini
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Luiz Carlos Soares de Carvalho
- Center for Science and Technology in Energy and Sustainability of Federal University of Reconcavo da Bahia, Feira de Santana, Bahia, Brazil
| | - Cássia da Luz Goulart
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Rayane Sebold
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil.,Course of Physiotherapy, Central Paulista University Center, Sao Carlos, Sao Paulo, Brazil
| | - Polliana Batista Dos Santos
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
| | - Meliza Goi Roscani
- Medicine Department, Federal University of Sao Carlos, Sao Carlos, Sao Paulo, Brazil
| | - Audrey Borghi-Silva
- Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of Sao Carlos, Sao Paulo, Brazil
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van Haarst A, McGarvey L, Paglialunga S. Review of Drug Development Guidance to Treat Chronic Obstructive Pulmonary Disease: US and EU Perspectives. Clin Pharmacol Ther 2019; 106:1222-1235. [PMID: 31334840 PMCID: PMC6896238 DOI: 10.1002/cpt.1540] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 05/04/2019] [Indexed: 12/11/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) remains a leading cause of death worldwide, yet only one new drug class has been approved in the last decade. However, resurgence in COPD treatment has been recently fueled by a greater understanding of the pathophysiology and natural history of the disease, as well as a growing prevalence and an aging population. Currently, there are nearly 25 novel drug targets in development. Furthermore, the indication has undergone some fundamental changes over the last couple of years, including an updated diagnosis paradigm, validation, and approval of patient‐reported outcome questionnaires for clinical trials, and drug development tools, such as a prognostic biomarker for patient selection. In the context of clinical trials, this review aims to summarize recent changes to the diagnosis and evaluation of COPD and to provide an overview of US and European regulatory guidance.
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Affiliation(s)
| | - Lorcan McGarvey
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, UK
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Medrinal C, Prieur G, Combret Y, Quesada AR, Debeaumont D, Bonnevie T, Gravier FE, Dupuis Lozeron E, Quieffin J, Contal O, Lamia B. Functional Electrical Stimulation-A New Therapeutic Approach to Enhance Exercise Intensity in Chronic Obstructive Pulmonary Disease Patients: A Randomized, Controlled Crossover Trial. Arch Phys Med Rehabil 2018. [PMID: 29524398 DOI: 10.1016/j.apmr.2018.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To evaluate the effect of quadriceps functional electrical stimulation (FES)-cycling on exertional oxygen uptake (V˙o2) compared with placebo FES-cycling in patients with chronic obstructive pulmonary disease (COPD). DESIGN A randomized, single-blind, placebo-controlled crossover trial. SETTING Pulmonary rehabilitation department. PARTICIPANTS Consecutive patients (N=23) with COPD Global Initiative for Chronic Obstructive Lung Disease stage 2, 3, or 4 (mean forced expiratory volume during the first second, 1.4±0.4L [50.3% predicted]) who had recently begun a respiratory rehabilitation program. INTERVENTION Two consecutive 30-minute sessions were carried out at a constant load with active and placebo FES-cycling. MAIN OUTCOME MEASURES The primary outcome was mean V˙o2 during the 30-minute exercise session. The secondary outcomes were respiratory gas exchange and hemodynamic parameters averaged over the 30-minute endurance session. Lactate values, dyspnea, and perceived muscle fatigue were evaluated at the end of the sessions. RESULTS FES-cycling increased the physiological response more than the placebo, with a greater V˙o2 achieved of 36.6mL/min (95% confidence interval [CI], 8.9-64.3mL/min) (P=.01). There was also a greater increase in lactate after FES-cycling (+1.5mmol/L [95% CI, .05-2.9mmol/L]; P=.01). FES-cycling did not change dyspnea or muscle fatigue compared with the placebo condition. CONCLUSIONS FES-cycling effectively increased exercise intensity in patients with COPD. Further studies should evaluate longer-term FES-cycling rehabilitation programs.
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Affiliation(s)
- Clément Medrinal
- Normandy University, UNIROUEN, and the Institute for Research and Innovation in Biomedicine, Rouen, France; Pulmonology Department, Le Havre Hospital, Montivilliers, France.
| | - Guillaume Prieur
- Pulmonology Department, Le Havre Hospital, Montivilliers, France
| | - Yann Combret
- Institute for Experimental Research, Pulmonology, ORL & Dermatology, Catholic University of Louvain, Brussels, Belgium; Physiotherapy Department, Le Havre Hospital, Montivilliers, France
| | | | - David Debeaumont
- Exercise and Respiratory Physiology Department, Bois Guillaume Hospital, Rouen University Hospital, Rouen Cedex, France
| | - Tristan Bonnevie
- Normandy University, UNIROUEN, and the Institute for Research and Innovation in Biomedicine, Rouen, France; ADIR Association, Bois Guillaume, France
| | | | - Elise Dupuis Lozeron
- Division of Clinical Epidemiology, Geneva University Hospitals, Geneva, Switzerland
| | - Jean Quieffin
- Pulmonology Department, Le Havre Hospital, Montivilliers, France
| | - Olivier Contal
- University of Applied Sciences and Arts of Western Switzerland (HES-SO), Lausanne, Switzerland
| | - Bouchra Lamia
- Normandy University, UNIROUEN, and the Institute for Research and Innovation in Biomedicine, Rouen, France; Pulmonology Department, Le Havre Hospital, Montivilliers, France; Intensive Care Unit, Respiratory Department, Rouen University Hospital, Rouen, France
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Szczegielniak J, Latawiec KJ, Łuniewski J, Stanisławski R, Bogacz K, Krajczy M, Rydel M. A study on nonlinear estimation of submaximal effort tolerance based on the generalized MET concept and the 6MWT in pulmonary rehabilitation. PLoS One 2018; 13:e0191875. [PMID: 29425213 PMCID: PMC5806867 DOI: 10.1371/journal.pone.0191875] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 01/02/2018] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The six-minute walk test (6MWT) is considered to be a simple and inexpensive tool for the assessment of functional tolerance of submaximal effort. The aim of this work was 1) to background the nonlinear nature of the energy expenditure process due to physical activity, 2) to compare the results/scores of the submaximal treadmill exercise test and those of 6MWT in pulmonary patients and 3) to develop nonlinear mathematical models relating the two. METHODS The study group included patients with the COPD. All patients were subjected to a submaximal exercise test and a 6MWT. To develop an optimal mathematical solution and compare the results of the exercise test and the 6MWT, the least squares and genetic algorithms were employed to estimate parameters of polynomial expansion and piecewise linear models. RESULTS Mathematical analysis enabled to construct nonlinear models for estimating the MET result of submaximal exercise test based on average walk velocity (or distance) in the 6MWT. CONCLUSIONS Submaximal effort tolerance in COPD patients can be effectively estimated from new, rehabilitation-oriented, nonlinear models based on the generalized MET concept and the 6MWT.
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Affiliation(s)
- Jan Szczegielniak
- Department of Physical Education and Physiotherapy, Opole University of Technology, Opole, Poland
| | - Krzysztof J. Latawiec
- Department of Electrical, Control and Computer Engineering, Opole University of Technology, Opole, Poland
| | - Jacek Łuniewski
- Department of Physical Education and Physiotherapy, Opole University of Technology, Opole, Poland
| | - Rafał Stanisławski
- Department of Electrical, Control and Computer Engineering, Opole University of Technology, Opole, Poland
| | - Katarzyna Bogacz
- Department of Physical Education and Physiotherapy, Opole University of Technology, Opole, Poland
| | - Marcin Krajczy
- Department of Physical Education and Physiotherapy, Opole University of Technology, Opole, Poland
| | - Marek Rydel
- Department of Electrical, Control and Computer Engineering, Opole University of Technology, Opole, Poland
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Rocco IS, Viceconte M, Pauletti HO, Matos-Garcia BC, Marcondi NO, Bublitz C, Bolzan DW, Moreira RSL, Reis MS, Hossne NA, Gomes WJ, Arena R, Guizilini S. Oxygen uptake on-kinetics during six-minute walk test predicts short-term outcomes after off-pump coronary artery bypass surgery. Disabil Rehabil 2017; 41:534-540. [PMID: 29279000 DOI: 10.1080/09638288.2017.1401673] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE We aimed to investigate the ability of oxygen uptake kinetics to predict short-term outcomes after off-pump coronary artery bypass grafting. METHODS Fifty-two patients aged 60.9 ± 7.8 years waiting for off-pump coronary artery bypass surgery were evaluated. The 6-min walk test distance was performed pre-operatively, while simultaneously using a portable cardiopulmonary testing device. The transition of oxygen uptake kinetics from rest to exercise was recorded to calculate oxygen uptake kinetics fitting a monoexponential regression model. Oxygen uptake at steady state, constant time, and mean response time corrected by work rate were analysed. Short-term clinical outcomes were evaluated during the early post-operative of off-pump coronary artery bypass surgery. RESULTS Multivariate analysis showed body mass index, surgery time, and mean response time corrected by work rate as independent predictors for short-term outcomes. The optimal mean response time corrected by work rate cut-off to estimate short-term clinical outcomes was 1.51 × 10-3 min2/ml. Patients with slower mean response time corrected by work rate demonstrated higher rates of hypertension, diabetes, EuroSCOREII, left ventricular dysfunction, and impaired 6-min walk test parameters. The per cent-predicted distance threshold of 66% in the pre-operative was associated with delayed oxygen uptake kinetics. CONCLUSIONS Pre-operative oxygen uptake kinetics during 6-min walk test predicts short-term clinical outcomes after off-pump coronary artery bypass surgery. From a clinically applicable perspective, a threshold of 66% of pre-operative predicted 6-min walk test distance indicated slower kinetics, which leads to longer intensive care unit and post-surgery hospital length of stay. Implications for rehabilitation Coronary artery bypass grafting is a treatment aimed to improve expectancy of life and prevent disability due to the disease progression; The use of pre-operative submaximal functional capacity test enabled the identification of patients with high risk of complications, where patients with delayed oxygen uptake kinetics exhibited worse short-term outcomes; Our findings suggest the importance of the rehabilitation in the pre-operative in order to "pre-habilitate" the patients to the surgical procedure; Faster oxygen uptake on-kinetics could be achieved by improving the oxidative capacity of muscles and cardiovascular conditioning through rehabilitation, adding better results following cardiac surgery.
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Affiliation(s)
- Isadora Salvador Rocco
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Marcela Viceconte
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Hayanne Osiro Pauletti
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Bruna Caroline Matos-Garcia
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Natasha Oliveira Marcondi
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Caroline Bublitz
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Douglas William Bolzan
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Rita Simone Lopes Moreira
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Michel Silva Reis
- c Department of Physical Therapy , Federal University of Rio de Janeiro , Rio de Janeiro , Brazil
| | - Nelson Américo Hossne
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Walter José Gomes
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil
| | - Ross Arena
- d Department of Physical Therapy and Integrative Physiology Laboratory, College of Applied Health Sciences , University of Illinois at Chicago , Chicago , IL , USA
| | - Solange Guizilini
- a Cardiology and Cardiovascular Surgery Disciplines , Federal University of Sao Paulo , Sao Paulo , Brazil.,b Department of Human Motion Sciences, Physical Therapy School , Federal University of Sao Paulo , Sao Paulo , Brazil
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Mancuso M, McFarland R, Klopstock T, Hirano M. International Workshop:: Outcome measures and clinical trial readiness in primary mitochondrial myopathies in children and adults. Consensus recommendations. 16-18 November 2016, Rome, Italy. Neuromuscul Disord 2017; 27:1126-1137. [PMID: 29074296 PMCID: PMC6094160 DOI: 10.1016/j.nmd.2017.08.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/24/2017] [Accepted: 08/30/2017] [Indexed: 01/01/2023]
Affiliation(s)
- Michelangelo Mancuso
- Department of Experimental and Clinical Medicine, Neurological Institute, University of Pisa, Italy.
| | - Robert McFarland
- Wellcome Trust Centre for Mitochondrial Research, Institute of Genetic Medicine, Department of Physiology and Functional Genomics NE1 3BZ, Newcastle University, Newcastle upon Tyne, UK
| | - Thomas Klopstock
- Friedrich-Baur-Institut an der Neurologischen Klinik und Poliklinik, LMU München, Ziemssenstr. 1a, 80336 München, Federal Republic of Germany
| | - Michio Hirano
- Department of Neurology, H. Houston Merritt Neuromuscular Research Center, Columbia University Medical Center, New York, NY, USA
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13
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Multimodel inference applied to oxygen recovery kinetics after 6-min walk tests in patients with chronic obstructive pulmonary disease. PLoS One 2017; 12:e0187548. [PMID: 29117249 PMCID: PMC5678891 DOI: 10.1371/journal.pone.0187548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/20/2017] [Indexed: 11/20/2022] Open
Abstract
6-min walk tests (6MWT) are routinely performed in patients with chronic obstructive pulmonary disease (COPD). Oxygen uptake ([Formula: see text]) kinetics during 6MWT can be modeled and derived parameters provide indicators of patients' exercise capacity. Post-exercise [Formula: see text] recovery also provides important parameters of patients' fitness which has not been extensively investigated in COPD. Several nonlinear regression models with different underlying biological assumptions may be suitable for describing recovery kinetics. Multimodel inference (model averaging) can then be used to capture the uncertainty in considering several models. Our aim was to apply multimodel inference in order to better understand the physiological underpinnings of [Formula: see text] recovery after 6MWT in patients with COPD. 61 patients with COPD (stages 2 to 4) were included in this study. Oxygen kinetics during 6MWT were modeled using nonlinear regression. Three statistical approaches (mixed-effects, meta-analysis and weighted regression) were compared in order to summarize estimates obtained from multiple kinetics. The recovery phase was modeled using 3 distinct equations (log-logistic, Weibull 1 and Weibull 2). Three models were fitted to the set of 61 kinetics. A significant model-averaged difference of 40.39 sec (SE = 17.1) in the time to half decrease of [Formula: see text] level ([Formula: see text]) was found between stage 2 and 4 (p = 0.0178). In addition, the Weibull 1 model characterized by a steeper decrease at the beginning of the recovery phase showed some improvement of goodness of fit when fitted to the kinetics of patients with stage 2 COPD in comparison with the 2 other models. Multimodel inference was successfully used to model [Formula: see text] recovery after 6MWT in patients with COPD. Significant model-averaged differences in [Formula: see text] were found between moderate and very severe COPD patients. Furthermore, specific patterns of [Formula: see text] recovery could be identified across COPD stages.
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14
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Interiano RB, Kaste SC, Li C, Srivastava DK, Rao BN, Warner WC, Green DM, Krasin MJ, Robison LL, Davidoff AM, Hudson MM, Fernandez-Pineda I, Ness KK. Associations between treatment, scoliosis, pulmonary function, and physical performance in long-term survivors of sarcoma. J Cancer Surviv 2017; 11:553-561. [PMID: 28669098 DOI: 10.1007/s11764-017-0624-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 05/30/2017] [Indexed: 11/28/2022]
Abstract
PURPOSE Longer survival for children with sarcoma has led to the recognition of chronic health conditions related to prior therapy. We sought to study the association of sarcoma therapy with the development of scoliosis. METHODS We reviewed patient demographics, treatment exposures, and functional outcomes for patients surviving >10 years after treatment for sarcoma between 1964 and 2002 at our institution. The diagnosis of scoliosis was determined by imaging. Functional performance and standardized questionnaires were completed in a long-term follow-up clinic. RESULTS We identified 367 patients, with median age at follow-up of 33.1 years. Scoliosis was identified in 100 (27.2%) patients. Chest radiation (relative risk (RR), 1.88 (95% confidence interval (CI), 1.21-2.92), p < 0.005) and rib resection (RR, 2.64 (CI, 1.79-3.89), p < 0.0001) were associated with an increased incidence of scoliosis; thoracotomy without rib resection was not. Of 21 patients who underwent rib resection, 16 (80.8%) had the apex of scoliosis towards the surgical side. Scoliosis was associated with worse pulmonary function (RR, 1.74 (CI, 1.14-2.66), p < 0.01) and self-reported health outcomes, including functional impairment (RR, 1.60 (CI, 1.07-2.38), p < 0.05) and cancer-related pain (RR, 1.55 (CI, 1.11-2.16), p < 0.01). Interestingly, pulmonary function was not associated with performance on the 6-min walk test in this young population. CONCLUSIONS Children with sarcoma are at risk of developing scoliosis when treatment regimens include chest radiation or rib resection. Identification of these risk factors may allow for early intervention designed to prevent adverse long-term outcomes. IMPLICATIONS FOR CANCER SURVIVORS Cancer survivors at risk of developing scoliosis may benefit from monitoring of pulmonary status and early physical therapy.
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Affiliation(s)
- Rodrigo B Interiano
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,University of Tennessee Health Science Center, 920 Court Avenue, Memphis, TN, 38163, USA
| | - Sue C Kaste
- Department of Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Department of Radiology, University of Tennessee Health Science Center, 920 Court Avenue, Memphis, TN, 38163, USA
| | - Chenghong Li
- Department of Biostatistics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Deo Kumar Srivastava
- Department of Biostatistics, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Bhaskar N Rao
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - William C Warner
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Daniel M Green
- Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, MS-173, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Matthew J Krasin
- Department of Radiation Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Leslie L Robison
- Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, MS-173, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Andrew M Davidoff
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,University of Tennessee Health Science Center, 920 Court Avenue, Memphis, TN, 38163, USA
| | - Melissa M Hudson
- Department of Oncology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, MS-173, 262 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Israel Fernandez-Pineda
- Department of Surgery, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN, 38105, USA.,University of Tennessee Health Science Center, 920 Court Avenue, Memphis, TN, 38163, USA
| | - Kirsten K Ness
- Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, MS-173, 262 Danny Thomas Place, Memphis, TN, 38105, USA.
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15
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Kinetics of Cardiac Output at the Onset of Exercise in Precapillary Pulmonary Hypertension. BIOMED RESEARCH INTERNATIONAL 2016; 2016:6050193. [PMID: 27990432 PMCID: PMC5136420 DOI: 10.1155/2016/6050193] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/30/2016] [Accepted: 10/24/2016] [Indexed: 12/19/2022]
Abstract
Purpose. Cardiac output (CO) is a cornerstone parameter in precapillary pulmonary hypertension (PH). The Modelflow (MF) method offers a reliable noninvasive determination of its beat-by-beat changes. So MF allows exploration of CO adjustment with the best temporal resolution. Methods. Fifteen subjects (5 PH patients, 10 healthy controls) performed a submaximal supine exercise on a cycle ergometer after 5 min of rest. CO was continuously determined by MF (COMF). Kinetics of heart rate (HR), stroke volume (SV), and CO were determined with 3 monoexponential models. Results. In PH patients, we observed a sudden and transitory drop of SV upon exercise onset. This implied a transitory drop of CO whose adjustment to a new steady state depended on HR increase. The kinetics of HR and CO for PH patients was slower than that of controls for all models and for SV in model 1. SV kinetics was faster for PH patients in models 2 and 3. Conclusion. This is the first description of beat-by-beat cardiovascular adjustments upon exercise onset in PH. The kinetics of HR and CO appeared slower than those of healthy controls and there was a transitory drop of CO upon exercise onset in PH due to a sudden drop of SV.
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Baty F, van Gestel AJ, Kern L, Brutsche MH. Oxygen Uptake Recovery Kinetics after the 6-Minute Walk Test in Patients with Chronic Obstructive Pulmonary Disease. Respiration 2016; 92:371-379. [DOI: 10.1159/000452307] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/04/2016] [Indexed: 11/19/2022] Open
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Hummel SL, Herald J, Alpert C, Gretebeck KA, Champoux WS, Dengel DR, Vaitkevicius PV, Alexander NB. Submaximal oxygen uptake kinetics, functional mobility, and physical activity in older adults with heart failure and reduced ejection fraction. J Geriatr Cardiol 2016; 13:450-7. [PMID: 27594875 PMCID: PMC4984569 DOI: 10.11909/j.issn.1671-5411.2016.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
BACKGROUND Submaximal oxygen uptake measures are more feasible and may better predict clinical cardiac outcomes than maximal tests in older adults with heart failure (HF). We examined relationships between maximal oxygen uptake, submaximal oxygen kinetics, functional mobility, and physical activity in older adults with HF and reduced ejection fraction. METHODS Older adults with HF and reduced ejection fraction (n = 25, age 75 ± 7 years) were compared to 25 healthy age- and gender-matched controls. Assessments included a maximal treadmill test for peak oxygen uptake (VO2peak), oxygen uptake kinetics at onset of and on recovery from a submaximal treadmill test, functional mobility testing [Get Up and Go (GUG), Comfortable Gait Speed (CGS), Unipedal Stance (US)], and self-reported physical activity (PA). RESULTS Compared to controls, HF had worse performance on GUG, CGS, and US, greater delays in submaximal oxygen uptake kinetics, and lower PA. In controls, VO2peak was more strongly associated with functional mobility and PA than submaximal oxygen uptake kinetics. In HF patients, submaximal oxygen uptake kinetics were similarly associated with GUG and CGS as VO2peak, but weakly associated with PA. CONCLUSIONS Based on their mobility performance, older HF patients with reduced ejection fraction are at risk for adverse functional outcomes. In this population, submaximal oxygen uptake measures may be equivalent to VO2 peak in predicting functional mobility, and in addition to being more feasible, may provide better insight into how aerobic function relates to mobility in older adults with HF.
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Affiliation(s)
- Scott L Hummel
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- VA Ann Arbor Healthcare System, Ann Arbor, MI, USA
| | - John Herald
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Craig Alpert
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | | | - Wendy S Champoux
- William Beaumont School of Medicine, Oakland University, Royal Oak, MI, USA
| | - Donald R Dengel
- School of Kinesiology, University of Minnesota, Minneapolis, MN, USA
| | | | - Neil B Alexander
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- VA Ann Arbor Healthcare System, Ann Arbor, MI, USA
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18
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Baty F, Ritz C, van Gestel A, Brutsche M, Gerhard D. Modeling the oxygen uptake kinetics during exercise testing of patients with chronic obstructive pulmonary diseases using nonlinear mixed models. BMC Med Res Methodol 2016; 16:66. [PMID: 27245328 PMCID: PMC4888741 DOI: 10.1186/s12874-016-0173-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 05/19/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The six-minute walk test (6MWT) is commonly used to quantify exercise capacity in patients with several cardio-pulmonary diseases. Oxygen uptake ([Formula: see text]O2) kinetics during 6MWT typically follow 3 distinct phases (rest, exercise, recovery) that can be modeled by nonlinear regression. Simultaneous modeling of multiple kinetics requires nonlinear mixed models methodology. To the best of our knowledge, no such curve-fitting approach has been used to analyze multiple [Formula: see text]O2 kinetics in both research and clinical practice so far. METHODS In the present study, we describe functionality of the R package medrc that extends the framework of the commonly used packages drc and nlme and allows fitting nonlinear mixed effects models for automated nonlinear regression modeling. The methodology was applied to a data set including 6MWT [Formula: see text]O2 kinetics from 61 patients with chronic obstructive pulmonary disease (disease severity stage II to IV). The mixed effects approach was compared to a traditional curve-by-curve approach. RESULTS A six-parameter nonlinear regression model was jointly fitted to the set of [Formula: see text]O2 kinetics. Significant differences between disease stages were found regarding steady state [Formula: see text]O2 during exercise, [Formula: see text]O2 level after recovery and [Formula: see text]O2 inflection point in the recovery phase. Estimates obtained by the mixed effects approach showed standard errors that were consistently lower as compared to the curve-by-curve approach. CONCLUSIONS Hereby we demonstrate the novelty and usefulness of this methodology in the context of physiological exercise testing.
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Affiliation(s)
- Florent Baty
- Department of Pulmonary Medicine, Cantonal Hospital St. Gallen, Rorschacherstrasse 95, St. Gallen, 9007, Switzerland.
| | - Christian Ritz
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Rolighedsvej 26, Frederiksberg C, 1958, Denmark
| | - Arnoldus van Gestel
- Department of Pulmonary Medicine, Cantonal Hospital St. Gallen, Rorschacherstrasse 95, St. Gallen, 9007, Switzerland
| | - Martin Brutsche
- Department of Pulmonary Medicine, Cantonal Hospital St. Gallen, Rorschacherstrasse 95, St. Gallen, 9007, Switzerland
| | - Daniel Gerhard
- School of Mathematics & Statistics, University of Canterbury, New Zealand, Private Bag 4800, Christchurch, 8140, New Zealand
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