Resting Energy Expenditure and Body Composition in Children and Adolescents With Genetic, Hypothalamic, Medication-Induced or Multifactorial Severe Obesity

Background

Pediatric obesity is a multifactorial disease which can be caused by underlying medical disorders arising from disruptions in the hypothalamic leptin-melanocortin pathway, which regulates satiety and energy expenditure.

Aim

To investigate and compare resting energy expenditure (REE) and body composition characteristics of children and adolescents with severe obesity with or without underlying medical causes.

Methods

This prospective observational study included pediatric patients who underwent an extensive diagnostic workup in our academic centre that evaluated endocrine, non-syndromic and syndromic genetic, hypothalamic, and medication-induced causes of obesity. REE was assessed by indirect calorimetry; body composition by air displacement plethysmography. The ratio between measured REE (mREE) and predicted REE (Schofield equations), REE%, was calculated, with decreased mREE defined as REE% ≤90% and elevated mREE ≥110%. Additionally, the influence of fat-free-mass (FFM) on mREE was evaluated using multiple linear regression.

Results

We included 292 patients (146 [50%] with body composition measurements), of which 218 (75%) patients had multifactorial obesity and 74 (25%) an underlying medical cause: non-syndromic and syndromic genetic (n= 29 and 28, respectively), hypothalamic (n= 10), and medication-induced (n= 7) obesity. Mean age was 10.8 ± 4.3 years, 59% were female, mean BMI SDS was 3.8 ± 1.1, indicating severe obesity. Mean REE% was higher in children with non-syndromic genetic obesity (107.4% ± 12.7) and lower in children with hypothalamic obesity (87.6% ± 14.2) compared to multifactorial obesity (100.5% ± 12.6, both p<0.01). In 9 children with pseudohypoparathyroidism type 1a, mean REE% was similar (100.4 ± 5.1). Across all patients, mREE was decreased in 60 (21%) patients and elevated in 69 (24%) patients. After adjustment for FFM, mREE did not differ between patients within each of the subgroups of underlying medical causes compared to multifactorial obesity (all p>0.05).

Conclusions

In this cohort of children with severe obesity due to various etiologies, large inter-individual differences in mREE were found. Consistent with previous studies, almost half of patients had decreased or elevated mREE. This knowledge is important for patient-tailored treatment, e.g. personalized dietary and physical activity interventions and consideration of pharmacotherapy affecting central energy expenditure regulation in children with decreased mREE.

RF02 | PSAT110 Resting Energy Expenditure and Body Composition in Children and Adolescents with Genetic, Hypothalamic, Medication-Induced or Multifactorial Severe Obesity

Background

Pediatric obesity is a multifactorial disease characterized by a prolonged imbalance between energy intake and expenditure. In rare cases, it is caused by underlying medical disorders arising from disruptions in the leptin-melanocortin pathway which regulates satiety and energy expenditure.

Aim

To investigate and compare resting energy expenditure (REE) and body composition characteristics of children and adolescents with severe obesity with and without underlying medical causes.

Methods

This prospective observational study included pediatric patients who underwent an extensive diagnostic workup in our academic center in which endocrine, non-syndromic and syndromic genetic, hypothalamic, and medication-induced causes of obesity were evaluated. Patients in whom no underlying medical cause was identified were classified as multifactorial obesity. REE was assessed by indirect calorimetry; body composition by air displacement plethysmography. The ratio measured REE (mREE) vs predicted REE (Schofield equations) was expressed as REE%, with decreased mREE defined as REE% ≤90% and elevated mREE as ≥110%. Additionally, the ratio mREE vs fat-free-mass (FFM) was calculated.

Results

We included 292 patients, of which 218 (75%) patients had multifactorial obesity and 74 (25%) had an underlying medical cause: non-syndromic and syndromic genetic (n= 29 and 28, respectively), hypothalamic (n= 10), and medication-induced (n= 7) obesity. Mean age was 10.8 ± 4.3 years, 59% were female, mean BMI SDS was 3.8 ± 1.1, indicating severe obesity. Mean REE% was higher in children with non-syndromic genetic obesity (107.4% ± 12.7) and lower in children with hypothalamic obesity (87.6% ± 14.2) compared to multifactorial obesity (100.5% ± 12.6, both p<0.01). Measured REE was decreased in 60 (21%) patients (corresponding to an average overprediction of daily caloric needs of 341 kcal/day) and elevated in 69 (24%) patients. Only in hypothalamic obesity, a larger proportion of patients showed a decreased REE compared to multifactorial obesity (6/10 vs 41/218, p<0.01). FFM was higher in children with non-syndromic obesity compared to multifactorial obesity (+7.5kg, p<0.001), but lower in syndromic obesity (-5.2kg, p=0.03), hypothalamic obesity (-12.6kg, p<0.001), and similar in medication-induced obesity (+1.5kg FFM, p=0.80). Mean mREE/FFM was 46.5 ± 10.6 kcal/day/kg FFM and did not differ between patients with underlying medical causes compared to multifactorial obesity (all p>0.05).

Conclusion

In this cohort of children with severe obesity due to various etiologies, large inter-individual differences in mREE were found. Almost half of patients had decreased or elevated mREE. When relating mREE to FFM, no differences were found between children with underlying medical causes versus multifactorial obesity. Thus, our study underlines the importance of measuring REE and relating mREE to FFM in children with early-onset severe obesity with or without underlying medical causes. This knowledge is important for patient-tailored treatment, e.g. personalized dietary or physical activity interventions and consideration of pharmacotherapy affecting central energy expenditure regulation in children with decreased mREE.

Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m., Saturday, June 11, 2022 1:18 p.m. - 1:23 p.m., Saturday, June 11, 2022 1:18 p.m. - 1:23 p.m.

Pediatric to adult transition care in neurogastroenterology and motility: A position paper from the American Neurogastroenterology and Motility Society and European Society of Neurogastroenterology and Motility

Transition services-programs that support adolescents and young adults (AYAs) as they move from a child-centered to a more autonomous, adult-orientated healthcare system-have been associated with improved short- and long-term healthcare outcomes. Unfortunately, there is a paucity of evidence exploring transition services within the neurogastroenterology and motility (NGM) field. The overall aim of this article, endorsed by the American Neurogastroenterology and Motility Society and European Society of Neurogastroenterology and Motility, is to promote a discussion about the role of transition services for patients with NGM disorders. The AYAs addressed herein are those who have: (a) a ROME positive disorder of gut-brain interaction (DGBI), (b) a primary or secondary motility disorder (including those with motility disorders that have been surgically managed), or (c) an artificial feeding requirement (parenteral or enteral tube feeding) to manage malnutrition secondary to categories (a) or (b). The issues explored in this position paper include the specific physical and psychological healthcare needs of patients with NGM disorders; key healthcare professionals who should form part of a secondary care NGM transition service; the triadic relationship between healthcare professionals, caregivers, and patients; approaches to selecting patients who may benefit most from transition care; methods to assess transition readiness; and strategies with which to facilitate transfer of care between healthcare professionals. Key areas for future research are also addressed, including the construction of NGM-specific transition readiness questionnaires, tools to assess post-transfer healthcare outcomes, and educational programs to train healthcare professionals about transition care in NGM.