Effects of Obesity and Sex on Ventilatory Constraints during a Cardiopulmonary Exercise Test in Children

Dharini M Bhammar; Celia W Nusekabel; Daniel P Wilhite; Shilpa Daulat; Yulun Liu; Rae I S Glover; Tony G Babb

doi:10.1249/MSS.0000000000003481

Effects of Obesity and Sex on Ventilatory Constraints during a Cardiopulmonary Exercise Test in Children

Med Sci Sports Exerc. 2024 May 15. doi: 10.1249/MSS.0000000000003481. Online ahead of print.

Authors

Dharini M Bhammar¹, Celia W Nusekabel¹, Daniel P Wilhite, Shilpa Daulat², Yulun Liu³, Rae I S Glover¹, Tony G Babb⁴

Affiliations

¹ Center for Tobacco Research, Division of Medical Oncology, Department of Internal Medicine, The Ohio State University, Columbus, OH.
² Department of Internal Medicine, Rush University, Chicago, IL.
³ School of Public Health, UT Southwestern Medical Center and Simmons Comprehensive Cancer Center, Dallas, TX.
⁴ Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital and UT Southwestern Medical Center, Dallas, TX.

PMID: 38768025
DOI: 10.1249/MSS.0000000000003481

Abstract

Purpose: Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e., expiratory flow limitation (EFL) and dynamic hyperinflation) during a maximal exercise test in children.

Methods: Thirty-four 8-12-year-old children without obesity (18 females) and 54 with obesity (23 females) completed pulmonary function testing and maximal cardiopulmonary exercise tests. EFL was calculated as the overlap between tidal flow-volume loops during exercise and maximal expiratory flow-volume loops. Dynamic hyperinflation was calculated as the change in inspiratory capacity from rest to exercise.

Results: Maximal minute ventilation was not different between children with and without obesity. Average end-inspiratory lung volumes (EILV) and end-expiratory lung volumes (EELV) were significantly lower during exercise in children with obesity (EILV: 68.8 ± 0.7%TLC; EELV: 41.2 ± 0.5%TLC) compared with children without obesity (EILV: 73.7 ± 0.8%TLC; EELV: 44.8 ± 0.6%TLC; P < 0.001). Throughout exercise, children with obesity experienced more EFL and dynamic hyperinflation compared with those without obesity (P < 0.001). Also, males experienced more EFL and dynamic hyperinflation throughout exercise compared with females (P < 0.001). At maximal exercise, the prevalence of EFL was similar in males with and without obesity, however the prevalence of EFL in females was significantly different with 57% of females with obesity experiencing EFL compared with 17% of females without obesity (P < 0.05). At maximal exercise, 44% of children with obesity experienced dynamic hyperinflation compared with 12% of children without obesity (P = 0.002).

Conclusions: Obesity in children increases the risk of developing mechanical ventilatory constraints such as dynamic hyperinflation and EFL. Sex differences were apparent with males experiencing more ventilatory constraints compared with females.