Altered skeletal muscle mitochondrial phenotype in COPD: disease vs. disuse

Patients with chronic obstructive pulmonary disease (COPD) exhibit an altered skeletal muscle mitochondrial phenotype, which often includes reduced mitochondrial density, altered respiratory function, and elevated oxidative stress. As this phenotype may be explained by the sedentary lifestyle that commonly accompanies this disease, the aim of this study was to determine whether such alterations are still evident when patients with COPD are compared to control subjects matched for objectively measured physical activity (PA; accelerometry). Indexes of mitochondrial density [citrate synthase (CS) activity], respiratory function (respirometry in permeabilized fibers), and muscle oxidative stress [4-hydroxynonenal (4-HNE) content] were assessed in muscle fibers biopsied from the vastus lateralis of nine patients with COPD and nine PA-matched control subjects (CON). Despite performing similar levels of PA (CON: 18 ± 3, COPD: 20 ± 7 daily minutes moderate-to-vigorous PA; CON: 4,596 ± 683, COPD: 4,219 ± 763 steps per day, P > 0.70), patients with COPD still exhibited several alterations in their mitochondrial phenotype, including attenuated skeletal muscle mitochondrial density (CS activity; CON 70.6 ± 3.8, COPD 52.7 ± 6.5 U/mg, P < 0.05), altered mitochondrial respiration [e.g., ratio of complex I-driven state 3 to complex II-driven state 3 (CI/CII); CON: 1.20 ± 0.11, COPD: 0.90 ± 0.05, P < 0.05), and oxidative stress (4-HNE; CON: 1.35 ± 0.19, COPD: 2.26 ± 0.25 relative to β-actin, P < 0.05). Furthermore, CS activity ( r = 0.55), CI/CII ( r = 0.60), and 4-HNE ( r = 0.49) were all correlated with pulmonary function, assessed as forced expiratory volume in 1 s ( P < 0.05), but not PA ( P > 0.05). In conclusion, the altered mitochondrial phenotype in COPD is present even in the absence of differing levels of PA and appears to be related to the disease itself. NEW & NOTEWORTHY Chronic obstructive pulmonary disease (COPD) is associated with debilitating alterations in the function of skeletal muscle mitochondria. By comparing the mitochondrial phenotype of patients with COPD to that of healthy control subjects who perform the same amount of physical activity each day, this study provides evidence that many aspects of the dysfunctional mitochondrial phenotype observed in COPD are not merely due to reduced physical activity but are likely related to the disease itself.

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Faculty Opinions recommendation of Cigarette smoke-induced oxidative stress: A role in chronic obstructive pulmonary disease skeletal muscle dysfunction.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.3927957.3677055 ◽

2010 ◽

Author(s):

Irfan Rahman ◽

Hongwei Yao

Keyword(s):

Oxidative Stress ◽

Chronic Obstructive Pulmonary Disease ◽

Skeletal Muscle ◽

Pulmonary Disease ◽

Cigarette Smoke ◽

Chronic Obstructive ◽

Muscle Dysfunction ◽

Obstructive Pulmonary Disease ◽

Skeletal Muscle Dysfunction

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Walking distance in incremental shuttle walking test as a predictor of physical activity in patients diagnosed with low-risk chronic obstructive pulmonary disease

SAGE Open Medicine ◽

10.1177/20503121211064716 ◽

2021 ◽

Vol 9 ◽

pp. 205031212110647

Author(s):

Shojiro Egoshi ◽

Jun Horie ◽

Akinori Nakagawa ◽

Yuriko Matsunaga ◽

Shinichiro Hayashi

Keyword(s):

Physical Activity ◽

Chronic Obstructive Pulmonary Disease ◽

Skeletal Muscle ◽

Muscle Strength ◽

Pulmonary Disease ◽

Low Risk ◽

Walking Distance ◽

Chronic Obstructive ◽

Obstructive Pulmonary Disease ◽

Walking Test

Objectives: Research on the determinants of physical activity in mildly symptomatic patients with chronic obstructive pulmonary disease is lacking. This study examined the predictors of physical activity in patients with low-risk chronic obstructive pulmonary disease. Methods: A total of 41 male patients with chronic obstructive pulmonary disease belonging to Group A of the Global Initiative for Chronic Obstructive Lung Disease were included. Regarding the objective index, the physical activity (number of steps/day and the amount of Ex (metabolic equivalent × hours)/day) of the participants was measured with a tri-axis accelerometer. In addition, regarding the evaluation index, respiratory function and dynamic lung hyperinflation were measured by a spirometer, skeletal muscle mass was measured using bioelectrical impedance analysis, skeletal muscle strength (grip and lower limb muscle strength) was measured using a dynamometer, exercise capacity was measured by the incremental shuttle walking test, and health-related quality of life was measured. Results: Significant correlations were found between the number of steps per day and age (ρ = −0.501, p < 0.01), forced vital capacity predictive values (ρ = 0.381, p < 0.05), dynamic lung hyperinflation (ρ = 0.454, p < 0.01), grip strength (ρ = 0.318, p < 0.05), and walking distance in incremental shuttle walking test (ρ = 0.779, p < 0.01), but not skeletal muscle mass, lower limb muscle strength, or health-related quality of life. A multiple-regression analysis with the number of steps per day as the dependent variable extracted only walking distance in incremental shuttle walking test, yielding a moderate single-regression equation (steps/day = −934.909 + 11.052 × walking distance in incremental shuttle walking test, adjusted R2 = 0.548, p < 0.001). Conclusion: It was suggested that the amount of physical activity of patients with low-risk chronic obstructive pulmonary disease could be predicted by walking distance in incremental shuttle walking test.

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Sensitivity, Accuracy, and Reproducibility of Biosensing (mHealth) Devices in Monitoring of Physical Activity and Respiratory Function in Smokers with and Without Respiratory Symptoms or Chronic Obstructive Pulmonary Disease (Preprint)

10.2196/preprints.20347 ◽

2020 ◽

Author(s):

Almaz Sharman ◽

Baurzhan Zhussupov ◽

Saule Nurakysh

Keyword(s):

Physical Activity ◽

Chronic Obstructive Pulmonary Disease ◽

Heart Rate ◽

Pulmonary Disease ◽

Respiratory Function ◽

Respiratory Symptoms ◽

Chronic Obstructive ◽

Grey Zone ◽

Obstructive Pulmonary Disease ◽

Home Setting

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a global public health problem, and continuous monitoring is essential for both its management as well as the management of other chronic diseases. Telemonitoring using mobile health (mHealth) devices has the potential to promote self-management, improve control, increase quality of life, and prevent hospital admissions. OBJECTIVE This feasibility and proof-of-concept study aims to assess utility (sensitivity, accuracy, and reproducibility) of biosensing (mHealth) devices in monitoring of physical activity and respiratory function in smokers with and without respiratory symptoms/COPD. METHODS A total of 3 cohorts, with 9 participants in each, used mHealth devices for 90 days while undergoing the current standard of care. These groups were: 9 “non-COPD,” otherwise healthy, smokers; 9 “grey zone” smokers (forced expiratory volume in 1 second/ forced vital capacity ≥0.70 after bronchodilator treatment; COPD Assessment Test ≥10); and 9 smokers diagnosed with Stage 1-3 COPD. Rates of recruitment, retention, and adherence will be measured. Overall, two mHealth devices were utilized in the study: (1) the AnaMed Original Equipment Manufacturer device (OEM) that measures distance, energy expenditure, heart rate, and heart rate variability by using photoplethysmographic method and displays the results on a watchface, smartphone or a tablet, and (2) the Air Next mobile spirometry device portable device that performs spirometric measurements (FEV1, FVC and FEV1/FVC) ratio by a turbine mechanism and displays the results on a smartphone or a tablet. The mHealth devices were compared against industry standards. Additionally, a questionnaire will be administered to assess the participants’ perceptions of the mHealth technologies used. RESULTS The AnaMed device was demonstrated as precise in measuring heart rate, and less so when measuring number of steps and meters. It is unreliable in measuring SpO2. It is easy to use, requires no significant technical support. The Air-Next Spirometer is a simple and very precise instrument for detecting obstructive airway diseases which was confirmed when compared with the industry standard. It is easy to use, which could make it especially useful non-specialized care and in-home setting and other areas. CONCLUSIONS We demonstrated that both devices, AnaMed and AirNext can provide precise measurements or heart rate and spirometric data, and it is feasible to incorporate them into a large-scale study. However, such task would require serious efforts to hire technical staff and to provide additional training for the clinical investigators to take care of technical and logistical issues, i.e. sending reminders, synching devices with smartphones, communication efforts. CLINICALTRIAL ClinicalTrials.gov NCT04081961; https://clinicaltrials.gov/ct2/show/NCT04081961

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Does physical inactivity cause chronic obstructive pulmonary disease?

Clinical Science ◽

10.1042/cs20090458 ◽

2010 ◽

Vol 118 (9) ◽

pp. 565-572 ◽

Cited By ~ 25

Author(s):

Nicholas S. Hopkinson ◽

Michael I. Polkey

Keyword(s):

Oxidative Stress ◽

Physical Activity ◽

Chronic Obstructive Pulmonary Disease ◽

Lung Function ◽

Pulmonary Disease ◽

Chronic Obstructive ◽

Activity Levels ◽

Lung Function Decline ◽

Obstructive Pulmonary Disease ◽

Physical Activity Levels

COPD (chronic obstructive pulmonary disease) is the most common pulmonary disease and is the only common cause of death in which mortality is presently rising. It is caused by the inhalation of smoke, which leads to oxidative stress and inflammation both in the lungs and systemically. Reduced physical activity is a well-recognized consequence of the condition, but we argue here that inactivity is itself an early cause of lung function decline and symptoms. This hypothesis is supported by data from population studies that link activity levels to decline in spirometric indices, both in smokers and non-smokers. In addition, smokers with low physical activity levels are more likely to be diagnosed subsequently with COPD. Physical exercise reduces oxidative stress, has an anti-inflammatory effect and reduces the frequency of upper respiratory tract infections, providing a number of mechanisms by which it could attenuate the harmful effects of smoking. There is sufficient evidence to justify population trials of lifestyle interventions aimed at improving physical activity levels and reducing lung function decline in people diagnosed with early COPD through spirometry screening.

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