Respiratory and Exercise Responses by Body Roundness Index in Obesity

The assessment will be performed in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria. Assessments will be conducted in a seated position with back support. To prevent the risk of infection, disposable mouthpieces and filters will be used for each participant. Forced vital capacity (FVC) will be measured. Values will be recorded in liter and as percentage (%) of predicted values. Measurements will be repeated three times, and the best value meeting measurement standardization criteria will be recorded.

Respiratory muscle strength assessment will be performed using an intraoral pressure measurement device (MicroRPM, Micro Medical, United Kingdom) in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria (ATS/ERS, 2002). Measurements will be conducted in a seated position while wearing a nose clip. To prevent the risk of infection, disposable mouthpieces and filters will be used for each participant. For maximal inspiratory pressure (MIP) measurement, participants will perform a maximal inspiratory effort through the mouth for a few seconds. Measurements will be repeated three times, and the best value meeting standardization criteria will be recorded in cmH₂O.

The assessment will be performed in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria. Assessments will be conducted in a seated position with back support. To prevent the risk of infection, disposable mouthpieces and filters will be used for each participant. FEV1 ratio will be measured. Values will be recorded percentage (%) of predicted values. Measurements will be repeated three times, and the best value meeting measurement standardization criteria will be recorded.

The assessment will be performed in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria. Assessments will be conducted in a seated position with back support. To prevent the risk of infection, disposable mouthpieces and filters will be used for each participant. FEV1/FVC ratio will be measured. Values will be recorded percentage (%) of predicted values. Measurements will be repeated three times, and the best value meeting measurement standardization criteria will be recorded.

Respiratory muscle strength assessment will be performed using an intraoral pressure measurement device (MicroRPM, Micro Medical, United Kingdom) in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria (ATS/ERS, 2002). Measurements will be conducted in a seated position while wearing a nose clip. To prevent the risk of infection, disposable mouthpieces and filters will be used for each participant. For maximal expiratory pressure (MEP) measurement, a maximal expiratory effort will be performed for a few seconds, and the values will be recorded. Measurements will be repeated three times, and the best value meeting standardization criteria will be recorded in cmH₂O.

Exercise capacity will be evaluated using the Six-Minute Walk Test (6MWT) according to the American Thoracic Society (ATS) guidelines with the Spiropalm 6MWT device (COSMED, Italy) (ATS, 2002). Before the test, participants will rest for at least 10 minutes, and baseline measurements including heart rate, blood pressure, oxygen saturation, dyspnea, and leg fatigue will be recorded. The test will be performed in a 30-meter indoor corridor, and participants will be instructed to walk as fast as possible for six minutes. Total walking distance will be recorded in meters. Heart rate, oxygen saturation, dyspnea, and fatigue levels will be reassessed after the test.

Ventilation (Unit of Measure: L/min) during the 6MWT will be assessed using the Spiropalm device.

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 the measurements. Assessments will be performed during daytime at a room temperature of 25°C. Participants will be measured while clothed and barefoot after removing their shoes, socks, and all metal accessories.

Body Roundness Index (BRI) will be calculated using waist circumference and height measurements according to the standardized BRI formula. The BRI is a continuous index with no fixed minimum or maximum value. Higher BRI values indicate greater body roundness and higher adiposity (worse outcome).

Peak ventilation (VEpeak) during the 6MWT will be assessed using the Spiropalm device.

Peak breathing reserve (BRpeak) (Unit of Measure: %) during the 6MWT will be assessed using the Spiropalm device.

Inspiratory capacity (IC) during the 6MWT will be assessed using the Spiropalm device.

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 the measurements. Assessments will be performed during daytime at a room temperature of 25°C. Participants will be measured while clothed and barefoot after removing their shoes, socks, and all metal accessories.