Body Composition, Functional Capacity, and Respiratory Muscle Endurance in Obesity With Restrictive Ventilatory Pattern

Investigation of the Relationship Between Body Composition, Functional Capacity, and Respiratory Muscle Endurance in Individuals With Obesity and a Restrictive Ventilatory Pattern

This observational cross-sectional study aims to examine the relationship between body composition, functional capacity, and respiratory muscle endurance in individuals with obesity and a restrictive ventilatory pattern. A total of 100 adults aged 25-60 years with a body mass index (BMI) ≥30 kg/m² and restrictive pulmonary function findings will be enrolled. Participants will evaluate body composition assessment using bioelectrical impedance analysis, pulmonary function testing by spirometry, respiratory muscle strength and endurance measurements, and functional capacity evaluation using the Six-Minute Walk Test (6MWT). The aim of this study is to evaluate the relationships between stem cell count (SCC), a novel anthropometric indicator called WWI, trunk muscle mass, and functional capacity in obese individuals with a restrictive ventilatory pattern.

Study Overview

• Status: Not yet recruiting
• Conditions: Obesity
• Intervention / Treatment: Other: Pulmonary Function, Body Composition, and Functional Capacity Assessment

• Study Type: Observational
• Enrollment (Estimated): 100

Contacts and Locations

• Study Contact: Name: Buket Akinci, Prof. Dr.; Phone Number: +90 505 6415692; Email: bakinci@biruni.edu.tr

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Obese Individuals with Restrictive Ventilatory Pattern

Description

Inclusion Criteria:

• Individuals aged between 25 and 60 years
• Individuals with a body mass index (BMI) ≥ 30 kg/m² according to the World Health Organization (WHO) classification
• Individuals demonstrating a restrictive ventilatory pattern (FVC < 80% predicted)
• Individuals who voluntarily agree to participate in the study

Exclusion Criteria:

• Individuals with a Charlson Comorbidity Index (CCI) score of 3 or higher
• Individuals with uncontrolled arrhythmia, hypertension, heart failure, diabetes mellitus, or unstable angina pectoris
• Individuals with cooperation impairments, orthopedic, or neurological conditions that may interfere with assessment or treatment
• Individuals with a history of lower extremity injury or surgery within the last six months
• Individuals diagnosed with diabetes mellitus who have complications such as nephropathy, retinopathy, or neuropathy
• Individuals with concomitant chronic respiratory disease
• Individuals with acute infection
• Individuals with middle ear pathologies (e.g., tympanic membrane rupture or otitis)
• Individuals with a history of spontaneous or trauma-related pneumothorax
• Current smokers
• Pregnant individuals
• Individuals with a STOP-Bang score of 3 or higher
• Individuals currently participating in a structured weight-loss diet program or receiving medical treatment for weight loss during the assessment period
• Individuals who have undergone endoscopic intervention and/or bariatric surgery within the last year

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Obese Individuals with Restrictive Ventilatory Pattern

Other: Pulmonary Function, Body Composition, and Functional Capacity Assessment; Participants will undergo a comprehensive assessment including pulmonary function testing using spirometry, body composition analysis using bioelectrical impedance analysis (BIA), respiratory muscle strength and endurance evaluation, and functional capacity assessment with the Six-Minute Walk Test (6MWT). Anthropometric measurements including body weight, height, waist circumference, hip circumference, and waist-to-height ratio will also be recorded.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Functional capacity	Participants' exercise capacity will be assessed using the Six-Minute Walk Test (6MWT) according to the American Thoracic Society (ATS) guidelines with the Spiropalm 6MWT system (Cosmed, Italy) (ATS, 2002). The test will be performed in a 30-meter indoor corridor following a minimum 10-minute rest period. Heart rate, blood pressure, oxygen saturation, dyspnea, and leg fatigue levels will be recorded before and after the test. Participants will be instructed to walk as fast as possible for six minutes and may rest or terminate the test if severe symptoms occur. Total walking distance will be recorded in meters, and any interruptions or symptoms during the test will be documented.	Day 1
Respiratory Muscle Endurance	Participants' respiratory muscle endurance will be assessed using an inspiratory muscle training device (POWERbreathe® K-Series K3, POWERbreathe International Ltd, UK). Measurements will be performed in a seated position with a nose clip applied and the device placed in the mouth. The assessment will be conducted using an incremental threshold loading protocol. At the beginning of the test, the threshold pressure will be set at 20% of the participant's maximal inspiratory pressure (MIP). Participants will be instructed to complete 30 breaths over a two-minute period. Individuals who tolerate this level will progress to subsequent stages with gradually increasing loads of 40%, 60%, 80%, and 100% of MIP, respectively. Oxygen saturation and heart rate will be recorded before and after the test using a pulse oximeter. Participants will also be informed that they may remove the device from their mouth and terminate the test at any time in the event of any discomfort or adverse symptoms.	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body fat mass	Participants' body fat mass (kg) will be measured using Bioelectrical Impedance Analysis (BIA). Participants will be informed about the test protocol and instructed to fast for 8-12 hours before the assessment, arrive with an empty bladder, and avoid fluid intake, food consumption, and vigorous physical activity prior to testing. Measurements will be performed during daytime at a room temperature of 25°C. Participants will be assessed while clothed and barefoot after removing their shoes, socks, and all metal accessories.	Day 1
Forced vital capacity (FVC)	Forced vital capacity (FVC) will be evaluated using a Pulmonary Function Test (PFT) in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria, utilizing the "COSMED Spiropalm 6MWT" device (COSMED, Italy) and its integrated PFT software (ATS & ERS, 2002). Assessments will be performed in a seated position with back support. To minimize the risk of infection, a disposable mouthpiece and filter will be used for each participant. Values will be recorded both in liters and as percentages (%) of predicted values. Measurements will be repeated three times, and the best value meeting the measurement standards will be recorded.	Day 1
Ventilation (VE)	Ventilation (VE) will be measured during the Six-Minute Walk Test (6MWT) using the Spiropalm device.	Day 1
Body muscle mass	Body muscle mass (kg) will be measured using Bioelectrical Impedance Analysis (BIA). Participants will be informed about the test protocol and instructed to fast for 8-12 hours before the assessment, arrive with an empty bladder, and avoid fluid intake, food consumption, and vigorous physical activity prior to testing. Measurements will be performed during daytime at a room temperature of 25°C. Participants will be assessed while clothed and barefoot after removing their shoes, socks, and all metal accessories.	Day 1
Forced expiratory volume in the first second (FEV1)	Forced expiratory volume in the first second (FEV1) will be evaluated using a Pulmonary Function Test (PFT) in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria, utilizing the "COSMED Spiropalm 6MWT" device (COSMED, Italy) and its integrated PFT software (ATS & ERS, 2002). Assessments will be performed in a seated position with back support. To minimize the risk of infection, a disposable mouthpiece and filter will be used for each participant. Values will be recorded both in liters and as percentages (%) of predicted values. Measurements will be repeated three times, and the best value meeting the measurement standards will be recorded.	Day 1
FEV1/FVC ratio	FEV1/FVC ratio will be evaluated using a Pulmonary Function Test (PFT) in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria, utilizing the "COSMED Spiropalm 6MWT" device (COSMED, Italy) and its integrated PFT software (ATS & ERS, 2002). Assessments will be performed in a seated position with back support. To minimize the risk of infection, a disposable mouthpiece and filter will be used for each participant. Values will be recorded both in liters and as percentages (%) of predicted values. Measurements will be repeated three times, and the best value meeting the measurement standards will be recorded	Day 1
Peak ventilation (VEpeak)	Peak ventilation (VEpeak) will be measured during the Six-Minute Walk Test (6MWT) using the Spiropalm device.	Day 1
Peak breathing reserve (BRpeak)	Peak breathing reserve (BRpeak) will be measured during the Six-Minute Walk Test (6MWT) using the Spiropalm device.	Day 1
Respiratory frequency (RF)	Respiratory frequency (RF) will be measured during the Six-Minute Walk Test (6MWT) using the Spiropalm device.	Day 1
Inspiratory capacity (IC)	Inspiratory capacity (IC) will be measured during the Six-Minute Walk Test (6MWT) using the Spiropalm device.	Day 1
Body muscle percentage	Body muscle percentage (%) will be measured using Bioelectrical Impedance Analysis (BIA). Participants will be informed about the test protocol and instructed to fast for 8-12 hours before the assessment, arrive with an empty bladder, and avoid fluid intake, food consumption, and vigorous physical activity prior to testing. Measurements will be performed during daytime at a room temperature of 25°C. Participants will be assessed while clothed and barefoot after removing their shoes, socks, and all metal accessories.	Day 1
Weight-Adjusted Waist Index (WWI)	Weight-Adjusted Waist Index (WWI) will be calculated by dividing waist circumference (cm) by the square root of body weight (kg).	Day 1

Collaborators and Investigators

• Sponsor: Biruni University

Study record dates

Study Major Dates

• Study Start (Estimated): June 30, 2026
• Primary Completion (Estimated): November 20, 2026
• Study Completion (Estimated): December 15, 2026

Study Registration Dates

• First Submitted: May 8, 2026
• First Submitted That Met QC Criteria: May 15, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 15, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Physiological Phenomena; Biochemical Phenomena; Chemical Phenomena; Body Constitution; Metabolism; Body Composition
• Other Study ID Numbers: Obesity2052026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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