Case Control Study
Copyright ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Pediatr. Sep 9, 2025; 14(3): 100306
Published online Sep 9, 2025. doi: 10.5409/wjcp.v14.i3.100306
Effects of body mass index on gastric motility: Comparing children with functional abdominal pain disorders and healthy controls
Amaranath Karunanayake, Shaman Rajindrajith, Manori Vijaya Kumari, Niranga Manjuri Devanarayana
Amaranath Karunanayake, Department of Physiology, Faculty of Medicine, University of Ruhuna, Galle 80000, Southern Province, Sri Lanka
Shaman Rajindrajith, Department of Pediatrics, Faculty of Medicine, University of Colombo, Colombo 00800, Western Province, Sri Lanka
Manori Vijaya Kumari, Department of Physiology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Anuradhapura 50000, North Central Province, Sri Lanka
Niranga Manjuri Devanarayana, Department of Physiology, Faculty of Medicine, University of Kelaniya, Ragama 11010, Western Province, Sri Lanka
Author contributions: Karunanayake A contributed to the study design, data collection, analysis and interpretation of data, and wrote the initial draft; Rajindrajith S helped design the study and contributed to revisions to the final manuscript; Kumari MV contributed to the study design and data collection; Devanarayana NM conceptualized the study and contributed to the study design, data collection (by conducting motility studies), interpretation of data, and writing and revising the manuscript. All authors approved the final version to be published.
Supported by The University of Kelaniya, Sri Lanka, Research Council Grant No. G23.
Institutional review board statement: This study was approved by the Ethical Review Committee, Faculty of Medicine, University of Kelaniya, Sri Lanka.
Informed consent statement: Written informed consent was obtained from a parent or a legal guardian of each participant.
Conflict-of-interest statement: All the authors report having no relevant conflicts of interest for this article.
STROBE statement: The authors have read the STROBE statement-checklist of items, and the manuscript was prepared and revised according to the STROBE statement-checklist of items.
Data sharing statement: The dataset is available from the corresponding author at niranga@kln.ac.lk. Participants gave informed consent for data sharing, but the presented data are anonymized, and the risk of identification is low.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Niranga Manjuri Devanarayana, MD, PhD, Professor, Department of Physiology, Faculty of Medicine, University of Kelaniya, Thalagolla Road, Ragama 11010, Western Province, Sri Lanka. niranga@kln.ac.lk
Received: August 13, 2024
Revised: February 15, 2025
Accepted: April 2, 2025
Published online: September 9, 2025
Processing time: 307 Days and 2.8 Hours
Abstract
BACKGROUND

Overweight children exhibit a higher prevalence of functional gastrointestinal disorders compared with their normal-weight peers, yet the underlying reasons remain unclear. Gastrointestinal motility, a key pathophysiological factor in functional gastrointestinal disorders, may be influenced by body mass index (BMI).

AIM

To evaluate the impact of BMI on gastric motility parameters in children with functional abdominal pain disorders (FAPDs).

METHODS

We assessed gastric motility in 176 children with FAPDs (61.4% females, mean age 7.94 years, SD 1.96 years) and 63 healthy controls (57.1% females, mean age 9.17 years, SD 1.90 years) at the Gastroenterology Research Laboratory, University of Kelaniya, Sri Lanka. FAPDs were diagnosed and subtyped using the Rome IV criteria: Functional abdominal pain 97 patients; irritable bowel syndrome 39 patients, functional dyspepsia (FD) 25 patients; and abdominal migraine 15 patients. Gastric motility was measured using a validated ultrasound method. Weight and height were measured using sensitive standard scales.

RESULTS

The BMIs of children with FAPDs and controls were 15.04 and 15.46 kg/m², respectively (P = 0.33). Fasting antral area (FAA) and antral area at 1 min (AA1) and 15 min (AA15) were significantly greater in patients with FAPD with a higher BMI (2.71 cm², 12.57 cm², and 7.19 cm², respectively) compared with those with a lower BMI (2.12 cm², 10.68 cm², and 6.13 cm², respectively) (P < 0.01). BMI positively correlated with FAA and AA15 (r = 0.18 and r = 0.19, respectively) (P < 0.01) in those with FAPDs. In controls, only AA1 was greater in the higher BMI group (12.51 cm² vs 9.93 cm²) and had a positive correlation (r = 0.33) (P ≤ 0.01). Subgroup analysis revealed that in patients with FD, BMI negatively correlated with gastric emptying rate (GER) (r = -0.59) and antral motility index (MI) (r = -0.49), while in functional abdominal pain, MI positively correlated (r = 0.25) with BMI (P ≤ 0.01).

CONCLUSION

In children with FAPDs, higher BMI was associated with increased gastric antral distention during fasting and postprandial periods (as indicated by FAA, AA1, and AA15) but not with contractility and transit (MI, GER). However, in the FD subgroup, high BMI correlated with reduced GER and MI. This indicates the possible role of BMI in gastric hypomotility and the pathophysiology of FD. These findings underscore the importance of lifestyle and dietary interventions aimed at optimizing BMI in the management of FAPDs, particularly FD.

Keywords: Body mass index; Gastric motility; Functional abdominal pain disorders; Functional gastrointestinal disorders; Sri Lanka

Core Tip: This study investigated the relationship between body mass index (BMI) and gastric motility in children with functional abdominal pain disorders (FAPDs). When considering FAPDs in general, higher BMI is associated with increased gastric antral distention but does not affect gastric contractility or transit. However, in the subgroup of children with functional dyspepsia, a higher BMI correlates with reduced gastric emptying rate and motility index, suggesting a role for BMI in gastric hypomotility. These findings offer new insights into how BMI influences gastrointestinal function in pediatric FAPDs, particularly in functional dyspepsia.