Functional Capacity, Subjective Dyspnea and Fatigue in Smokers

NCT07520981 | Recruiting

• 1 other identifier: 2026/4
• Study Type: observational
• Target: 107
• Locations: 1 country
• Sites: 1

Brief Summary

Smoking remains a significant public health problem among the young adult population. Epidemiological studies in Turkey show a steadily decreasing age of smoking initiation and a remarkably high rate of smoking among university-aged individuals. Exposure to secondhand smoke is known to have negative effects on the respiratory system, cardiovascular system, and peripheral muscle function. Impaired lung ventilation, reduced gas exchange, and insufficient oxygen transport due to smoking can lead to decreased exercise tolerance, premature fatigue, and increased perception of exertional dyspnea. These effects can manifest as a decrease in functional capacity even before the development of a clinically significant respiratory disease. Functional capacity is an important indicator reflecting an individual's ability to perform daily living activities and is frequently assessed in clinical research using submaximal exercise tests. The 6-Minute Walk Test is a widely used, valid, and reliable test for assessing cardiorespiratory endurance and overall functional status. Similarly, the 1-Minute Sit-Stand Test is recommended as a practical and applicable method for evaluating lower extremity muscle endurance and functional performance. Dyspnea is a multidimensional symptom reflecting an individual's subjective perception of respiratory discomfort and is assessed using scales such as the Modified Medical Research Council and the Borg Dyspnea Scale. The Turkish Thoracic Society's dyspnea assessment reports indicate that exertional dyspnea may increase in smokers even if respiratory function tests are within normal limits. Fatigue, on the other hand, is a significant symptom that negatively affects an individual's daily living activities and physical functionality, arising from inflammatory processes, impaired oxygenation, and decreased physical activity levels associated with smoking. The Fatigue Severity Scale is a validated and reliable scale for assessing the impact of fatigue on an individual's physical and social life. While studies in the literature examine the effects of smoking on respiratory function and exercise capacity, studies that address the relationship between functional capacity and subjective dyspnea and fatigue in young adult smokers are limited. In particular, evaluating functional test results such as the 6-Minute Walk Test and the 1-Minute Sit-Stand Test together with dyspnea and fatigue perception will contribute to the early identification of subclinical functional effects. The aim of this study is to examine the relationships between functional capacity (6-Minute Walk Test, 1-Minute Sit-Stand Test, and Timed Up and Go Test) and subjective dyspnea (Modified Medical Research Council Scale - mMRC) and fatigue level (Fatigue Severity Scale) in young adult smokers aged 18-30 years. The findings of this study are expected to draw attention to the functional effects of smoking in young adults, contribute to the development of preventive health approaches, and facilitate the planning of physiotherapy-based assessment and intervention programs.

Conditions

Smoking

Keywords

functional capacity; subjectice dyspnea; fatigue; young adult smoker

Outcome Measures

Primary Outcomes (5)

• 6-Minute Walk Test

  Participants will be asked to walk the longest possible distance in a straight corridor for 6 minutes. At the end of the test, the total walking distance will be recorded in meters. The test will be administered according to the standard protocol recommended by the American Thoracic Society.

  4 weeks

• 1-Minute Sit-Stand Test

  Participants will be recorded on the number of times they stand up completely from a chair and sit down again within 60 seconds without using their arms. This test is a valid and reliable method for evaluating lower extremity muscle endurance and functional performance.

  4 weeks

• Timed Up and Go Test

  Participants will be asked to stand up from a chair, walk 3 meters, turn around, return to the starting point, and sit back down in the chair; the test duration will be recorded in seconds. The Timed Up and Go test is a widely used, valid, and reliable test for evaluating functional mobility, balance, and gait performance.

  4 weeks

• Subjective Dyspnea Assessment

  Participants' perception of dyspnea will be assessed using the Modified Medical Research Council Dyspnea Scale. The Modified Medical Research Council scale ranges from 0 to 4, with higher scores indicating greater perceived dyspnea severity. This scale is widely used to evaluate the level of dyspnea experienced during activities of daily living.

  4 weeks

• Fatigue Assessment

  Fatigue level will be assessed using the Fatigue Severity Scale. The Fatigue Severity Scale consists of 9 items, each scored on a scale from 1 to 7, and the final score is calculated as the mean of all items (range: 1-7). Higher scores indicate greater fatigue severity, and a mean score of ≥4 is considered clinically significant fatigue. The Turkish version of the FSS has been shown to be valid and reliable.

  4 weeks

Secondary Outcomes (1)

• Physical Activity Level

  4 weeks

Study Arms (1)

Group 1

Assessment group

Other: Assessment

Interventions

Assessment OTHER

In accordance with standard testing protocols, all participants will undergo the following assessments in order: Physical Activity Assessment (International Physical Activity Questionnaire), Functional Capacity Assessment (6-Minute Walk Test, 1-Minute Sit-to-Stand Test, and Timed Up and Go Test), Subjective Dyspnea Assessment (Modified Medical Research Council Dyspnea Scale), and Fatigue Severity Assessment (Fatigue Severity Scale).

Group 1

Eligibility Criteria

• Age: 18 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

The study was planned to include volunteer individuals aged 18-30 who are university students and currently smoke.

You may qualify if:

• Being between 18 and 30 years of age.
• Being actively enrolled in university.
• Being a current smoker,
• Having been a regular smoker for at least the last 6 months,
• Having a daily cigarette consumption of ≥1 cigarette/day.
• Volunteering to participate in the study and providing written informed consent.
• Having the cognitive and physical capacity to understand and complete the tests to be administered.

You may not qualify if:

• Having a diagnosed chronic respiratory disease (asthma, COPD, bronchiectasis, interstitial lung disease, etc.),
• Having had an upper or lower respiratory tract infection within the last 4 weeks. Having a diagnosed heart disease (coronary artery disease, heart failure, arrhythmia, etc.),
• Having a history of uncontrolled hypertension.
• Having orthopedic problems affecting walking, sitting/standing, or balance,
• Having a history of lower extremity surgery or serious injury within the last 6 months.
• Having a history of neurological disease affecting balance, coordination, or motor control (stroke, multiple sclerosis, epilepsy, etc.).
• Having a systemic disease that may prevent participation in exercise (uncontrolled diabetes, severe anemia, etc.),
• Being pregnant or within the first 6 months postpartum.
• Having conditions that may endanger the participant's safety during functional tests, o Refusal to complete the tests or inability to cooperate during the evaluation.

Sponsors & Collaborators

• Istinye University: lead

Study Sites (1)

Kubra Kardeş

Istanbul, 34010, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Smoking; Fatigue

Interventions

Restraint, Physical

Condition Hierarchy (Ancestors)

Behavior; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Behavior Control; Therapeutics; Immobilization; Investigative Techniques

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Asst. Prof.

Study Record Dates

• First Submitted: April 3, 2026
• First Posted: April 9, 2026
• Study Start: April 15, 2026
• Primary Completion (Estimated): July 15, 2026
• Study Completion (Estimated): July 30, 2026
• Last Updated: June 9, 2026

Record last verified: 2026-06

Locations

TU (1)