Inflammation and Oxidative Stress in COPD

February 23, 2026 updated by: Esra Yazar

The Effect of Pulmonary Rehabilitation on 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.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

27

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Turkey (Türkiye)
    • Kadikoy
      • Istanbul, Kadikoy, Turkey (Türkiye), 34730
        • Istanbul Medeniyet University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients aged 40 to 80 years with a diagnosis of stable COPD, defined according to the GOLD criteria (FEV₁/FVC < 70% and FEV₁ < 70% predicted), who are former smokers with a smoking history of at least 10 pack-years, and who are referred to the pulmonary rehabilitation program of our institution, will be consecutively enrolled in the study.

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Baseline (before pulmonary rehabilitation) and after 8 weeks of pulmonary rehabilitation

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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.
Baseline (before pulmonary rehabilitation) and after 8 weeks of pulmonary rehabilitation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Esra Yazar

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 6, 2026

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

May 1, 2026

Study Registration Dates

First Submitted

January 21, 2026

First Submitted That Met QC Criteria

January 21, 2026

First Posted (Actual)

January 29, 2026

Study Record Updates

Last Update Posted (Actual)

February 25, 2026

Last Update Submitted That Met QC Criteria

February 23, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 23.10.2025; 2025/0255

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

All IPD used in the results publication

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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