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CompletedNCT07520981Updated Aug 31, 2026

Functional Capacity, Subjective Dyspnea and Fatigue in Smokers

An observational study in Smoking, sponsored by Istinye University. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 30 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-31.

Sponsored by Istinye University · Observational

Study type
Observational
Model
Other
Time perspective
Prospective
Enrollment
103
Ages
18 Years to 30 Years
Sex
All
01

Study 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.

02

Conditions studied

  • Smoking

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Keywords

  • functional capacity
  • subjectice dyspnea
  • fatigue
  • young adult smoker
03

In context

Smoking

268 studies on the registry are indexed under Smoking; 136 are open to participants now.

This study's enrollment of 103 is below the median of 116 across 55 observational studies indexed under Smoking.

Browse Smoking studies →

Lead sponsor

Istinye University is the lead sponsor of 207 studies on the registry; 88 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 30 Years
Sexes eligible
All
Accepts healthy volunteers
Yes
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.

Inclusion criteria

  • 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.

Exclusion criteria

Exclusion Criteria:

  • 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.
05

Study design

Observational model
Other
Time perspective
Prospective
Enrollment
103 participants (actual)
Patient registry
No

Groups and cohorts

  • Group 1

    Assessment group

    Other: Assessment

Interventions

  • OtherAssessment

    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).

06

What researchers measure

Primary outcomes

  1. 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.

    Time frame: 4 weeks

  2. 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.

    Time frame: 4 weeks

  3. 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.

    Time frame: 4 weeks

  4. 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.

    Time frame: 4 weeks

  5. 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.

    Time frame: 4 weeks

Secondary outcomes

  1. Physical Activity Level

    Participants' physical activity level will be assessed using the International Physical Activity Questionnaire - Short Form. Data will be expressed as MET-minutes/week, where higher values indicate higher levels of physical activity. Based on International Physical Activity Questionnaire - Short Form scoring guidelines, participants will be classified into low, moderate, and high physical activity levels.

    Time frame: 4 weeks

07

Study locations

1 site
  • Kubra Kardeş
    Istanbul, 34010, Turkey (Türkiye)
08

References and documents

Individual participant data

Plan to share: Undecided

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 31, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07520981
Lead sponsor
Istinye University
Responsible party
Kubra Kardes (Asst. Prof., Istinye University) — Principal investigator
First posted
Apr 9, 2026
Start date
Apr 15, 2026
Primary completion
Jul 30, 2026
Completion
Aug 15, 2026
Last update
Aug 31, 2026

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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This study is completed, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.

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