Gastric Emptying In Healthy Children Using The Spirulina Breath Test: The Impact Of Gender, Body Size, And Pubertal Development

Background There are no pediatric norms for gastric emptying (GE) measured by nuclear scintigraphy. The C-13-labeled, stable isotope GE breath test (GEBT) is a non-radioactive alternative. We aimed to determine normative GEBT ranges in a cohort of healthy children and examine the influence of age, gender, puberty, and body surface area (BSA).Methods Healthy children ages 8-18 years completed the [C-13]-Spirulina platensis GEBT after an overnight fast. Breath samples were collected at baseline, every 15 min x 1 h, then every 30 min for 4 h total. The (CO2)-C-13 excretion rate was determined by the change in (CO2)-C-13/(CO2)-C-12 over time in each breath sample, expressed as kPCD (Percent C-13 Dose excreted/min). A mixed model with random time was used for multivariable analysis and outcome fit into a quadratic model.Key Results The 100 subjects completed the test meal within allotted time. Median (IQR) age was 13.5 (11.3-15.5) years; 51% were female. Females had lower (CO2)-C-13 excretion rates (slower GE) than males across time (p < 0.001) while decreased excretion rates correlated with higher BSA (p = 0.015). Gender differences were also noted within pubertal stages with females showing slower GE. Multivariable analysis suggested that pre-pubertal children have faster GE than both peri- and post-pubertal groups (p < 0.0001).Conclusions & Inferences Gender, puberty, and BSA influence GE rates in healthy children more than age. Although further data are needed, pubertal stage and hormonal influences may be unique factors to consider when assessing GE in children.