Effects of Obesity in the Aged

NCT05028309 | Recruiting

• 2 other identifiers: STU-122010-1083R01AG070262-02S1
• Study Type: interventional
• Target: 72
• Locations: 1 country
• Sites: 1

Brief Summary

The overall objective of this application is to investigate the effects of obesity on lung function, exercise tolerance, and DOE in older obese adults as compared with older adults without obesity, using a novel probe for mechanically unloading the thorax at rest and during exercise. The investigators will use 1) continuous negative cuirass pressure, and 2) assisted biphasic cuirass ventilation to decrease obesity-related effects in older obese adults. Our approach will be to examine respiratory function, exercise tolerance, and DOE with and without mechanical unloading in older obese men and women (65-75 yr), including those with respiratory symptoms (defined by a score of 1 or 2 on the modified Medical Research Council Dyspnea Scale), as compared with older adults without obesity. Specific Aims: The investigators will test the following hypotheses in older adults with and without obesity: Aim 1) Obesity will decrease respiratory function but to a greater extent in older obese adults with respiratory symptoms, (as evidenced by altered pulmonary function and breathing mechanics at rest); Aim 2) Obesity will decrease exercise tolerance (as evidenced by peak V•O2 in ml/min/kg, i.e., physical fitness), but not cardiorespiratory fitness (as evidenced by peak V•O2 in % of predicted based on ideal body wt), except in older obese adults with respiratory symptoms where both may be reduced during graded cycle ergometry. Aim 3) Obesity will increase DOE but to a greater extent in older obese adults with respiratory symptoms as evidenced by increased ratings of perceived breathlessness (sensory \& affective dimensions) during exercise. Aim 4) Mechanical unloading of the thorax will improve respiratory function, submaximal exercise tolerance, and DOE in older obese adults, but to a greater extent in older obese adults with respiratory symptoms.

Conditions

Obesity; Aging

Outcome Measures

Primary Outcomes (12)

• Change in Pulmonary Function: Lung Volumes

  Pulmonary function is comprised of several physiological variables but this study will primarily measure Lung Volume: FRC (liters) and TLC (liters)

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic)

• Change in Exercise Tolerance - Peak VO2

  Exercise Tolerance is represented by several physiological variables but the primary variable is Maximal oxygen uptake (L/min and percent predicted)

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic).

• Change in Dyspnea on Exertion

  Dyspnea on Exertion is represented using the Borg Scale which provides Ratings of Perceived Breathlessness (RPB) during constant load exercise cycling. The Borg Scale measures from 0-10, where 0 = no breathlessness and 10 = maximal breathlessness.

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic).

• Changes in PANAS Questionnaire

  Positive and Negative Affect Schedule. This scale consists of a number of words that describe different feelings and emotions.

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic).

• Modified Medical Research Council Dyspnea Scale (mMRC Dyspnea Scale)

  Investigate the qualities of respiratory sensations (e.g., "effort of breathing", "breathing heavy", "breathing shallow") during exercise before and after mechanical unloading of the chest wall

  Outcome measures will be assessed immediately after completion of mMRC questionnaire (during study visit 2)

• Dyspnoea-12

  This questionnaire is designed to help us learn more about how their breathing is troubling them.

  Outcome measures will be assessed immediately after completion of Dyspnoea-12 questionnaire (during study visit 2)

• ASI

  The Anxiety Sensitivity Index (ASI) is a 16 item scale containing items specifying different concerns someone could have regarding their anxiety.

  Outcome measures will be assessed immediately after completion of ASI questionnaire (during study visit 2)

• HADS

  HADS (Hospital Anxiety and Depression Scale) aims to measure symptoms of anxiety (HADS Anxiety) and depression (HADS Depression). HADS score: 0-7 = normal; 8-10 = mild; 11-14 = moderate; 15-21 = severe

  Outcome measures will be assessed immediately after completion of HADS questionnaire (during study visit 2)

• SDS-MC

  The Marlowe-Crowne Social Desirability Scale (MC-SDS) is a 33-item self-report questionnaire that assesses whether or not respondents are concerned with social approval.

  Outcome measures will be assessed immediately after completion of MC-SDS questionnaire (during study visit 2)

• IPAQ

  International Physical Activity Questionnaires (IPAQ) is a 27-item self-reported measure of physical activity

  Outcome measures will be assessed immediately after completion of IPAQ questionnaire (during study visit 2)

• WSQ

  Workforce Sitting Questionnaire (WSQ) is to estimate how much time they usually spend sitting in each of the following activities on a working day and a non-working day.

  Outcome measures will be assessed immediately after completion of WSQ questionnaire (during study visit 2)

• SF-12

  SF-12 is a health-related quality-of-life questionnaire

  Outcome measures will be assessed immediately after completion of SF-12 questionnaire (during study visit 2)

Secondary Outcomes (9)

• Changes in forced vital capacity (FVC)

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic)

• Changes in forced expiratory volume (FEV)

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic)

• Changes in forced expiratory volume in 1 second (FEV1)

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic)

• Changes in FEV1/FVC Ratio

  Outcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic)

• Changes is peak flow

  ChangesOutcome measures will be assessed within 24-48hrs after completion of each study condition (baseline, control, continuous, and dynamic) between conditions (visits 3-6) compared to baseline between cohorts

Study Arms (1)

Interventional Arm

EXPERIMENTAL

Older group of adults (65-75 yrs). Everyone enrolled uses the 'intervention'/ external cuirass - mechanical unloading of thorax

Other: Mechanical unloading of the Thorax using an external cuirass

Interventions

Mechanical unloading of the Thorax using an external cuirass OTHER

External cuirass (i.e., a plastic shell over the thorax) will be used to mechanically unload the chest wall. The cuirass has different operating modes. It can generate a constant negative pressure over the chest wall (e.g., -20cmH2O) or it can be triggered off mouth flow so it can generate a negative pressure on the chest wall during inspiration (e.g., -21cmH2O) and a positive pressure during expiration (e.g., +7cmH2O).

Interventional Arm

Eligibility Criteria

• Age: 65 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Nonsmokers who have no history of smoking
• No personal history of significant mental illness
• No weight loss dietary restrictions
• No current or past history of significant substance or alcohol abuse
• No history, evidence, or uncontrolled symptoms of heart disease
• No history of uncontrolled hypertension
• No current medications that may interfere with exercise capacity
• No recent history or indication of asthma
• No musculoskeletal abnormality that would preclude exercise
• No serious health conditions that would preclude study goals or participation in exercise (per PI \& medical staff \& preliminary or follow up testing; including significant other diseases, occult asthma, prior surgeries-especial lung or abdominal, or history of chemotherapy that could affect lung or heart function)
• Only postmenopausal women will be included.
• Women on hormone replacement therapy will be allowed to participate if the dosage remains similar during the entire protocol.

You may not qualify if:

• Volunteers with a mMRC score of 3 or 4 will be excluded due to likeliness of underlying disease.
• Individuals participating in regular vigorous conditioning exercise such as running, jogging, aerobics, cycling, or swimming more than three times per week will be excluded. However, if subjects have an exceedingly high exercise capacity (greater than 2 SD of predicted), they will be excluded.
• Maximal cycle ergometry test will be used to determine if further participation in testing is appropriate for the participant (e.g., normal exercise test, exclude presence of provokable ECG changes suggestive of heart disease, or dangerous arrhythmias or exercise induced hypertension or bronchoconstriction. If the participant develops an abnormal ECG or shows other signs of exercise intolerance or if signs of cardiovascular disease are noted during the exercise test, it will be terminated and the participant will be referred to their personal physician for further evaluation (see DMSP).
• Premenopausal women will be excluded.

Sponsors & Collaborators

• University of Texas Southwestern Medical Center: lead
• National Institute on Aging (NIA): collaborator

Study Sites (1)

Institute for Exercise and Environmental Medicine, UT Southwestern and Texas Health Resources

Dallas, Texas, 75231, United States

RECRUITING

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Tony G Babb, Ph.D.

  University of Texas Southwestern Medical Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Research Nurse

CONTACT

214-345-6574; IEEMLung@TexasHealth.org

Abide Abulimiti, Ph.D.

CONTACT

214-345-6501; Abidanabulimiti@TexasHealth.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PROFESSOR, Cardiopulmonary Laboratory Director, Effie and Wofford Cain Chair in Cardiopulmonary Research, Institute of Exercise and Environmental Medicine, Division of Pulmonary and Critical Care Medicine

Study Record Dates

• First Submitted: August 17, 2021
• First Posted: August 31, 2021
• Study Start: December 1, 2021
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: August 28, 2025

Record last verified: 2025-08

Locations

US (1)