Gastric and Postgastric Processing of 13C Markers Renders the 13C Breath Test an Inappropriate Measurement Method for the Gastric Emptying of Lipid Emulsions in Healthy Adults

Helen L Parker; Dian Liu; Jelena Curcic; Marc-Olivier Ebert; Werner Schwizer; Michael Fried; Andreas Steingoetter

doi:10.3945/jn.117.248765

Gastric and Postgastric Processing of ¹³C Markers Renders the ¹³C Breath Test an Inappropriate Measurement Method for the Gastric Emptying of Lipid Emulsions in Healthy Adults

J Nutr. 2017 Jul;147(7):1258-1266. doi: 10.3945/jn.117.248765. Epub 2017 May 31.

Authors

Helen L Parker^{1

2

3}, Dian Liu⁴, Jelena Curcic^{1

4}, Marc-Olivier Ebert⁵, Werner Schwizer¹, Michael Fried¹, Andreas Steingoetter^{6

4}

Affiliations

¹ Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
² School of Medicine, Pharmacy, and Health, Durham University, Stockton-on-Tees, United Kingdom; and.
³ Institute of Health and Society, Newcastle University, Newcastle upon Tyne, United Kingdom.
⁴ Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland.
⁵ Laboratory of Organic Chemistry, ETH Zurich, Zurich, Switzerland.
⁶ Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland; steingoetter@biomed.ee.ethz.ch.

PMID: 28566523
DOI: 10.3945/jn.117.248765

Abstract

Background: Breath tests (BTs) present an alternative gastric-emptying (GE) measure. However, their efficacy in the measurement of the GE rate of lipid emulsions (LEs) is unknown.Objective: The objective of this work was to investigate the validity of ¹³C BTs as a measure of fat GE rate in LEs.Methods: The lipophilic ¹³C octanoate (OCC) BT marker was investigated for fat GE with the hydrophilic ¹³C sodium acetate (ACC) and the triglyceride ¹³C trioctanoin (TCC) markers as comparators. Data from 2 randomized studies were combined [50 healthy participants; 25 men, mean ± SD age: 23 ± 2.8 y; mean ± SD body mass index (in kg/m²): 22.4 ± 1.7]. Each participant was given either an acid-stable LE (LE1) or an acid-unstable LE (LE4) at each visit. Twenty-three participants underwent simultaneous MRI. The effect of LEs on ¹³CO₂ excretion profiles was determined. The BT half-emptying times (BT T₅₀) were validated with the MRI half-emptying time of the ingested fat volume (MRI T₅₀).Results: The effect of LEs on ¹³CO₂ excretion depended on the properties of the ¹³C marker. T₅₀ for OCC was shorter by 98 min for LE1 than for LE4 (P < 0.001). Other markers showed either no LE dependency or a longer T₅₀ for LE1 than for LE4. No difference in T₅₀ between OCC and ACC was detected in LE1. In LE4, the T₅₀ was longer by 154 min (P < 0.0001). There was some concordance between MRI T₅₀ and OCC BT T₅₀ for LE1 (r_c = 0.7). No other marker showed any concordance with fat GE. ¹³C-Nuclear magnetic resonance in vitro findings were compatible with changes in the kinetics of phase transfer of OCC dependent on its protonation state.Conclusions: The structure of fat present in the stomach affects ¹³CO₂ excretion. The chemical properties of the ¹³C marker and their gastric and postgastric interaction with fat renders ¹³CO₂ excretion an inappropriate measure of LE emptying in healthy adults. This trial was registered at clinicaltrials.gov as NCT02226029 and NCT02602158.

Keywords: 13C breath test; acetate; gastric emptying; lipid emulsion; magnetic resonance imaging; octanoate; trioctanoin.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Breath Tests / methods*
Carbon / metabolism*
Carbon Isotopes
Cross-Over Studies
Emulsions / chemistry
Gastric Emptying / physiology*
Humans
Lipid Metabolism / physiology*
Lipids / administration & dosage*
Postprandial Period

Substances

Carbon Isotopes
Emulsions
Lipids
Carbon

Associated data

ClinicalTrials.gov/NCT02226029
ClinicalTrials.gov/NCT02602158
ClinicalTrials.gov/NCT02226029
ClinicalTrials.gov/NCT02602158