Respiratory Function, Physical Activity and Fatigue in SLE

Respiratory Function, Functional Capacity, Physical Activity, and Fatigue in Patients With Systemic Lupus Erythematosus: A Cross-Sectional Study

Increasing awareness of possible pulmonary involvement in patients with systemic lupus erythematosus (SLE) will enable earlier diagnosis of the disease and minimize damage accumulation. According to our research, no study has been found that examines respiratory functions in detail in SLE patients and investigates their relationship with functional capacity, physical activity, and fatigue levels. Our primary aim is to compare respiratory functions, functional capacity, physical activity, and fatigue levels between patients with SLE and healthy controls. Our secondary aim is to investigate the relationship between respiratory functions with functional capacity, physical activity levels, and fatigue in SLE patients.

Study Overview

• Status: Completed
• Conditions: Systemic Lupus Erythematosus

Detailed Description

Systemic lupus erythematosus (SLE) is a chronic, inflammatory, autoimmune disease characterized by multisystem involvement. SLE can affect any organ or tissue, including the skin, joints, kidneys, central and peripheral nervous systems, lungs, and heart. Approximately 50% of patients with SLE may experience pulmonary involvement during the course of their disease. The most commonly reported manifestations in patients with SLE are pleurisy, diffuse alveolar hemorrhage, shrinking lung syndrome, interstitial lung disease, and pulmonary arterial hypertension.

Although estimates exist, the exact prevalence of pulmonary disease is unknown, and study findings have varied. In this context, our aim is to compare respiratory function, functional capacity, physical activity, and fatigue levels in patients with SLE with those in healthy controls. Our secondary aim is to investigate the relationship between respiratory function and functional capacity, physical activity level, and fatigue in patients with SLE.

Pulmonary function of the patients will be evaluated using pulmonary function tests. The level of physical activity of the participants will be assessed using the Global Physical Activity Questionnaire. Functional capacity will be evaluated with the 6-Minute Walk Test. Fatigue will be assessed using the Fatigue Severity Scale. Statistical analyses of the data obtained from the study will be performed using the Statistical Package for Social Sciences (SPSS) software.

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Fatih
    • Istanbul, Fatih, Turkey (Türkiye)
      • İstanbul University-Cerrahpaşa

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Individuals aged 18-65 years with a diagnosis of SLE

Description

Inclusion Criteria:

• Patients who have been followed with a diagnosis of systemic lupus erythematosus for at least 1 year
• Able to ambulate independently
• No cognitive or mental impairment
• Willing to participate in the study

Exclusion Criteria:

• Presence of major musculoskeletal disease affecting the lower extremities
• Presence of severe disease affecting the cardiovascular system
• Being pregnant
• Smoking
• Having a diagnosis of restrictive/interstitial lung disease due to the underlying condition

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Individuals with systemic lupus erythematosus; Individuals diagnosed with systemic lupus erythematosus according to the American College of Rheumatology classification criteria. Participants will be adults aged 18-65 years.
Healthy individuals; Age- and sex-matched healthy participants without any medical conditions (including neurological, genetic, or psychiatric disorders) that would prevent them from completing the tests.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Forced Vital Capacity (FVC)	The pulmonary function test will be performed using the COSMED Pony FX device in accordance with the American Thoracic Society and European Respiratory Society guidelines.	Time Frame: Baseline (day of enrollment) assessment
Forced Expiratory Volume (FEV1)	The pulmonary function test will be performed using the COSMED Pony FX device in accordance with the American Thoracic Society and European Respiratory Society guidelines.	Baseline (day of enrollment) assessment
Tiffeneau Index (FEV1/FVC)	The pulmonary function test will be performed using the COSMED Pony FX device in accordance with the American Thoracic Society and European Respiratory Society guidelines.	Baseline (day of enrollment) assessment
Peak Expiratory Flow (PEF)	The pulmonary function test will be performed using the COSMED Pony FX device in accordance with the American Thoracic Society and European Respiratory Society guidelines.	Baseline (day of enrollment) assessment
Functional Capacity	Functional capacity is assessed using the 6-Minute Walk Test according to the criteria of the American Thoracic Society. Participants are instructed to walk as fast as possible, but without running, at their own pace along a 30-meter flat corridor for 6 minutes. The distance covered is recorded in meters.	Time Frame: Baseline (day of enrollment) assessment
Physical Activity Level	The participants' physical activity status is assessed using the Global Physical Activity Questionnaire. The questionnaire consists of 16 questions. In the work and leisure activity sections, vigorous and moderate physical activities are assessed, while in the transportation section, moderate physical activities are assessed. In addition, there is an extra question for sedentary time. In each section, one yes/no question is followed by open-ended questions on the number of days per week and the duration per day. As a result of the questionnaire, the total weekly MET-minutes of physical activity are calculated. Moderate-intensity physical activities correspond to 4 MET/min, and vigorous-intensity physical activities correspond to 8 MET/min. Weekly total MET-minutes are calculated by multiplying with these coefficients.	Baseline (day of enrollment) assessment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fatigue Level	Fatigue is assessed using the Fatigue Severity Scale. The scale consists of 9 items. Participants are asked to select a number from 1 to 7 for each statement, indicating the extent to which they agree with it (1: strongly disagree; 7: strongly agree). The scores obtained for all items are summed and then divided by nine to calculate the final score. A score of four or higher generally indicates severe fatigue.	Baseline (day of enrollment) assessment

Collaborators and Investigators

• Sponsor: Melis Usul
• Investigators: Study Director: Ela Tarakçı, Professor, Istanbul University - Cerrahpasa

Study record dates

Study Major Dates

• Study Start (Actual): September 5, 2025
• Primary Completion (Actual): October 15, 2025
• Study Completion (Actual): November 30, 2025

Study Registration Dates

• First Submitted: September 15, 2025
• First Submitted That Met QC Criteria: September 25, 2025
• First Posted (Actual): September 26, 2025

Study Record Updates

• Last Update Posted (Actual): March 24, 2026
• Last Update Submitted That Met QC Criteria: March 23, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: systemic lupus erythematosus; functional capacity; respiratory function
• Additional Relevant MeSH Terms: Pathologic Processes; Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Respiratory Tract Diseases; Respiration Disorders; Pathological Conditions, Signs and Symptoms; Skin and Connective Tissue Diseases; Lupus Erythematosus, Systemic; Respiratory Aspiration
• Other Study ID Numbers: 2025/05-1560

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No