Respiratory Effects of Obesity in Children: Longitudinal Consequences After 6 Years of Aging

The purpose of the study is to re-examine body composition, respiratory function, exercise tolerance, and dyspnea on exertion (DOE) in children with obesity (CWO) and children without obesity (CWOO) who were originally studied as 8-12-year-olds between 2016-2023 (i.e., originally Tanner score ≤ 3; 90 participants; 26 CWOO & 64 CWO).

Study Overview

• Status: Enrolling by invitation
• Conditions: Childhood Obesity
• Intervention / Treatment: Other: Weight Loss

Detailed Description

The prevalence of childhood obesity increases with age (20.7% aged 6-11 & 22.2% aged 12-19; NHANES 2017-2020). CWO, compared with CWOO, are more likely to have chronic health conditions.

Results from the investigator's prior grant (HL136643) show that over one year, CWO can add four times as much fat weight as CWOO. However, it is unknown if this rate of increase in fat weight continues into adolescence and early adulthood, and whether respiratory function, exercise tolerance, or DOE are progressively worsened by increasing obesity. Furthermore, there could be a sex difference in the effects of obesity, given the different growth characteristics for boys and girls.

The investigator's long-term objective is to investigate the effects of 6 years of aging on body composition, respiratory function, exercise tolerance, and DOE in CWO and CWOO.

Specific Aims: The investigators will test the following hypotheses in CWO and CWOO after 6 years of aging:

Aim 1) CWO originally studied at 8-12 years old will demonstrate a greater increase in fat weight and lower respiratory function (i.e., altered pulmonary function & breathing mechanics at rest) than in CWOO originally studied at 8-12 years old;

Aim 2) CWO originally studied at 8-12 years old will demonstrate lower exercise tolerance measured during graded cycle ergometry (as evidenced by peak V • O2 in ml/min/kg, i.e., physical fitness) than in CWOO originally studied at 8-12 years old, but not lower cardiorespiratory fitness (as evidenced by peak V • O2 in % of predicted based on ideal body wt., i.e. cardiorespiratory fitness);

Aim 3) CWO originally studied at 8-12 years old will demonstrate greater DOE as evidenced by increased ratings of perceived breathlessness during constant load exercise cycling than in CWOO originally studied at 8-12 years old; and

• Study Type: Observational
• Enrollment (Estimated): 90

Contacts and Locations

Study Locations

• United States
  • Texas
    • Dallas, Texas, United States, 75231
      • Institute for Exercise and Environmental Medicine, UT Southwestern and Texas Health Presbyterian Hospital Dallas

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

The participants originally studied as 8-12-year-olds between 2016-2023 as part of the investigator's R01 HL136643.

Description

Inclusion Criteria:

The participants originally studied as 8-12-year-olds between 2016-2023 as part of the investigator's R01 HL136643.

Exclusion Criteria:

1. Children not able to follow directions, adequately perform procedures (e.g., pulmonary function tests), or keep appointments (e.g., no shows for testing).
2. If a child developed an abnormal ECG, showed other signs of clinical exercise intolerance, or signs of cardiovascular/lung disease during the exercise test, testing was terminated, and the child was referred to their personal physician for further evaluation.
3. Women who are pregnant or could possibly be pregnant (i.e. not using approved birth control measures and sexually active) will be excluded because of changes in body size during pregnancy and because unforeseeable risks to the fetus.
4. Presence of significant disease defined as a disease which in the opinion of the investigator may put the subject at risk because of participation in the study or a disease that may influence the results of the study or the subject's ability to participate in the study.
5. Patients who are non-English speaking will be excluded from the study because the tests performed are very effort dependent, detailed and require technical communication between the staff and the patient. The investigators feel that a translator would not be able to translate the technical terms fast enough to instruct the patient in the testing.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Children Without Obesity; No intervention or treatment will be administered. This group will not return after initial visits.
Children With Obesity; No intervention or treatment will be administered. This group will not return after initial visits.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.
Exercise Tolerance - Peak VO2	Exercise Tolerances is represented by several physiological variables but the primary variable is Maximal oxygen uptake (L/min and percent predicted)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.
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.	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pulmonary Function: Spirometry	Spirometry includes: Forced vital capacity (% predicted), Forced Expiratory Volume in 1 second (FEV1) (% predicted), FEV1/FVC (% predicted), and peak flow (% predicted.)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.
Pulmonary Function: Diffusing Capacity	Diffusing Capacity: Diffusing capacity of lung for carbon monoxide(DLco) (ml/mmHg/min)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.
Exercise Tolerance: Work Rate	Associated variables such as work rate (W)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.
Exercise Tolerance: Minute Ventilation	Associated variables such as pulmonary ventilation (L/min)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study..
Exercise Tolerance: Operational Lung Volumes	Associated variables such as operational lung volumes (EELV and EILV as a % of TLC)	Change from Baseline in differences between nonobese and obese children. Outcome measures will be assessed within 48-72 hours after completion of each study.

Collaborators and Investigators

• Sponsor: University of Texas Southwestern Medical Center
• Collaborators: National Heart, Lung, and Blood Institute (NHLBI)
• Investigators: Principal Investigator: Tony G Babb, Ph.D., University of Texas Southwestern Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): August 23, 2024
• Primary Completion (Estimated): August 31, 2029
• Study Completion (Estimated): August 31, 2029

Study Registration Dates

• First Submitted: May 29, 2024
• First Submitted That Met QC Criteria: June 6, 2024
• First Posted (Actual): June 7, 2024

Study Record Updates

• Last Update Posted (Estimated): September 5, 2025
• Last Update Submitted That Met QC Criteria: August 28, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Obesity; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Pediatric Obesity
• Other Study ID Numbers: STU-2024-0444; 5R01HL136643-05 (U.S. NIH Grant/Contract)

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
• product manufactured in and exported from the U.S.: No