Endocrine Abstracts

Introduction: Paediatric obesity is increasing globally. By 2050, obesity is expected to cost the UK NHS £10 billion annually.¹ Physical activity and exercise are recognised interventions to reduce BMI.² However, the physiological response to exercise is not understood. Understanding physiological responses in people with obesity (PwO) can inform the prescription of safe rehabilitation exercise programmes. This pilot study explored the feasibility of CPET to assess exercise capacity in PwO.

Methods: Patients >135 cm, >12 years old, <160 kg and willing to perform a maximal exercise test, were recruited from our ‘Complications of Excess Weight’ clinic. Each performed incremental ramp CPET. Key data (VO², HR, RER and Watts) were obtained at rest, anaerobic threshold and peak exercise.

Results: 15 patients (75% male, mean age 14.8years, mean BMI 42.8) performed CPET. 93% (14) had at least one comorbidity, most commonly ASD/ADHD (7) or hyperphagia (4). 93% (14) achieved maximum exercise performance. At rest, mean VO², HR and RER were 3.2±1.6 mL/min per kg, 103±15 bpm and 0.89±0.12. At anaerobic threshold these increased to 11.9±5.1 mL/min per kg, 150±16 bpm and 0.95±0.09. At peak exercise, they were 15.2±5.2 mL/min per kg, 174±14 bpm and 1.1±0.09. Mean load resistance was 96±37 W at anaerobic threshold and 135±49 W at peak exercise. Compared to healthy adolescents, our mean VO² peak values were low (15.2±5.2 mL/min per kg versus 42.6 mL/min per kg).³ Severe deconditioning was the main reason for reduced exercise capacity. There were no cardiac arrhythmias, episodes of hypoxia or other abnormal events.

Discussion: This pilot study provides evidence that maximal CPET is achievable and provides informative data in adolescent PwO. Testing usefully determines the parameters within which exercise can be safely recommended to help promote physical activity and stimulate weight loss.

References: 1. Public Health England (2017). Health matters: obesity and the food environment. (Health matters: obesity and the food environment – GOV.UK (www.gov.uk)) Accessed February 2023

2. Nowicka, P & Flodmark, CE (2007). Physical activity—key issues in treatment of childhood obesity. Acta Paediatrica, 96, 39–45.

3. Amedro P, Gavotto A, Guillaumont S, et al (2018). Cardiopulmonary fitness in children with congenital heart diseases versus healthy children. Heart, 104(12), 1026–1036.