# Adolescent Normative Intervals for Body Surface Gastric Mapping: Spectral Analysis

## TL;DR

This study creates reference ranges for a non-invasive test that measures stomach activity in adolescents, helping doctors better understand normal and abnormal results.

## Contribution

The study provides the first normative reference intervals for adolescent body surface gastric mapping metrics.

## Key findings

- Median principal gastric frequency was 3.06 cycles per minute with a reference interval of 2.72–3.37.
- No significant correlations were found between BSGM metrics and demographic or anthropometric factors.
- Normative intervals were established for four key BSGM metrics, including rhythm stability and amplitude ratios.

## Abstract

Body surface gastric mapping (BSGM) non‐invasively assesses gastric myoelectrical activity along with real‐time symptom reporting. In adults, the development of normative intervals has underpinned new explanatory phenotypes, aiding clinical decision‐making. This study established normative reference intervals for adolescent BSGM metrics.

Healthy adolescents aged 12–17 years with a BMI ≤ 35 kg/m2 were recruited from New Zealand, Australia, and the United States. BSGM using Gastric Alimetry (Alimetry, New Zealand) involved a 30‐min fast, followed by a 480‐kcal meal, and a 4‐h postprandial recording. Reference intervals were calculated for four validated metrics: Principal Gastric Frequency (PGF), body mass index (BMI)‐adjusted amplitude, Gastric Alimetry Rhythm Index (GA‐RI, indicating rhythm stability), and the fed: fasted amplitude ratio (ff‐AR). Results were reported at the median and 5th and/or 95th percentiles as appropriate.

A total of 107 participants (52.8% female, median age 14 [IQR 13–16], median BMI 20.1 [IQR 18.75–22.40]) with mixed ethnicities were included. No substantive correlations were observed between BSGM metrics and demographics or anthropometric data. Therefore, a single set of normative reference intervals was established. Median PGF was 3.06 cycles per minute; reference interval 2.72–3.37. Median BMI‐adjusted amplitude was 37.80 μV; reference interval 20.0–72.0. Median GA‐RI was 0.51; reference interval ≥ 0.22. Median ff‐AR was 2.12; reference interval ≥ 1.0.

This study presents normative reference intervals for BSGM spectral metrics in adolescent populations, informing the interpretation of tests in research and clinical practice.

This study establishes Body Surface Gastric Mapping (BSGM) normative reference intervals for adolescents.Establishing these adolescent reference intervals would improve diagnostic confidence and confirm normal versus abnormal gastric myoelectric activity.These normative reference intervals support test interpretation and allow specific phenotyping of gastric abnormalities for the adolescent population and guide symptoms management.

This study establishes Body Surface Gastric Mapping (BSGM) normative reference intervals for adolescents.

Establishing these adolescent reference intervals would improve diagnostic confidence and confirm normal versus abnormal gastric myoelectric activity.

These normative reference intervals support test interpretation and allow specific phenotyping of gastric abnormalities for the adolescent population and guide symptoms management.

This study establishes Body Surface Gastric Mapping (BSGM) normative reference intervals for adolescents. Establishing these adolescent reference intervals would improve diagnostic confidence and confirm normal versus abnormal gastric myoelectric activity. These normative reference intervals support test interpretation and allow specific phenotyping of gastric abnormalities for the adolescent population and guide symptom management.