Inflammation and Oxidative Stress in COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide, characterized by persistent airflow limitation, chronic inflammation, and increased oxidative stress. Despite optimal pharmacological treatment, many patients continue to experience symptoms, reduced exercise capacity, and frequent exacerbations. Pulmonary rehabilitation (PR) is an evidence-based, non-pharmacological intervention that improves symptoms, functional capacity, quality of life, and survival in patients with COPD; however, its biological effects on inflammatory and oxidative stress pathways remain insufficiently defined.

This study aims to evaluate the effects of pulmonary rehabilitation on systemic inflammation and oxidative stress in patients with stable COPD. Serum levels of pro-inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor alpha [TNF-α]) and the epithelial alarmin interleukin-33 (IL-33), which is released in response to airway epithelial injury, as well as nuclear factor erythroid 2-related factor 2 (NRF-2) gene and/or protein expression as a key regulator of antioxidant defense, will be measured before and after a standardized pulmonary rehabilitation program. By assessing changes in these biomarkers, this study seeks to determine whether pulmonary rehabilitation exerts disease-modifying effects beyond symptomatic improvement and functional outcomes.

The findings are expected to provide novel insights into the biological mechanisms of pulmonary rehabilitation and to support its role as a targeted, cost-effective intervention in the comprehensive management of COPD.

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Key information

Conditions

Inflamation COPD Chronic Disease Disease Attributes Lung Diseases Lung Diseases, Obstructive Oxidative Stress Pathologic Processes Pathological Conditions, Signs and Symptoms Pulmonary Disease, Chronic Obstructive Pulmonary Rehabilitation Respiratory Tract Diseases

Age range

40 year–80 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Istanbul Medeniyet University

Istanbul, Kadikoy, 34730, Turkey (Türkiye)

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Adults aged 40-80 years with a diagnosis of stable COPD
Airflow limitation defined according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (forced expiratory volume in 1 second / forced vital capacity [FEV₁/FVC] < 70% and forced expiratory volume in 1 second [FEV₁] < 70% predicted)
Former smokers with a smoking history of at least 10 pack-years
Clinically stable disease at the time of enrollment
Ability and willingness to participate in the pulmonary rehabilitation program
Provision of written informed consent

Exclusion criteria

Current smokers
History of acute COPD exacerbation or respiratory infection within the past 6 weeks
Presence of other chronic lung diseases (e.g., bronchiectasis, interstitial lung disease, asthma)
Active malignancy
Severe or uncontrolled cardiovascular disease, including recent acute myocardial infarction or malignant arrhythmias
Neurological, orthopedic, or psychiatric conditions that preclude objective functional assessment or participation in exercise training
Use of antioxidant or vitamin supplementation within the past 4 weeks
Determination by a cardiologist that participation in an exercise-based rehabilitation program is not medically appropriate

Treatment and study plan

Pulmonary rehabilitation

Behavioral

Participants will undergo a standardized, supervised pulmonary rehabilitation program consisting of exercise training, breathing exercises, and patient education. The program will include aerobic exercise training (treadmill or cycle ergometer), strength training of upper and lower limb muscles, and respiratory muscle training, conducted under the supervision of a multidisciplinary rehabilitation team. Sessions will be performed multiple times per week over a predefined program duration. The intervention will be applied in addition to standard pharmacological treatment, with no changes to maintenance medications during the study period.

Primary outcomes

Change in Inflammatory and Oxidative Stress Biomarkers After Pulmonary Rehabilitation in COPD Patients

Time frame: Baseline (before pulmonary rehabilitation) and after 8 weeks of pulmonary rehabilitation

The primary outcome measure is the change in serum levels of inflammatory and oxidative stress biomarkers following the pulmonary rehabilitation program in patients with stable COPD. Serum concentrations of IL-6, TNF-α, and IL-33, as well as NRF-2 gene and/or protein expression, will be measured before and after the intervention to evaluate the biological effects of pulmonary rehabilitation on systemic inflammation and oxidative stress.

Secondary outcomes

Association Between Changes in Inflammatory and Oxidative Stress Biomarkers and Clinical and Functional Outcomes After Pulmonary Rehabilitation

Time frame: Baseline (before pulmonary rehabilitation) and after 8 weeks of pulmonary rehabilitation

The secondary outcome measure is the relationship between levels and changes in inflammatory and oxidative stress biomarkers and changes in clinical and functional parameters following pulmonary rehabilitation in patients with stable COPD. Changes in serum IL-6, TNF-α, IL-33, and NRF-2-related parameters will be correlated with post-rehabilitation changes in dyspnea severity, exercise capacity, and health-related quality of life measures.

Sponsors and collaborators

Lead sponsor

Esra Yazar

Other

Registry information

Official study title

The Effect of Pulmonary Rehabilitation on Inflammation and Oxidative Stress in COPD

Important dates

Study start: 2026
Primary completion: 2026
Study completion: 2026
First posted: Jan 29, 2026
Registry last updated: Feb 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

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