Alimentary Tract
13C-octanoic acid breath test (OBT) with a new test meal (EXPIROGer®): Toward standardization for testing gastric emptying of solids

https://doi.org/10.1016/j.dld.2010.01.001Get rights and content

Abstract

Background

Standardization of the 13C-octanoic acid breath test is still lacking.

Aim

To evaluate the accuracy of the 13C-octanoic acid breath test using a new standardized ready-to-eat, gluten-, glucose-, and lactose-free muffin.

Methods

Healthy subjects were recruited and sorted by sex and age. Patients with diabetic gastroparesis and untreated celiac disease with known gastric motility disorders were also tested with the new labelled muffin. Expired breath 13CO2 was analysed and t1/2 was calculated.

Results

Overall, 131 healthy subjects were enrolled. The reference range of t1/2 was 88 ± 29 min with the value of 146 min as the upper limit of normal range. No significant difference in t1/2 was found among subjects sorted by sex or age. The within-subject variability of t1/2 was 17%. Mean (±standard deviation) t1/2 values were 179 ± 50 min in patients with diabetic gastroparesis (n = 8) and 151 ± 20 min in those with untreated celiac disease (n = 11) (p  0.001 vs controls).

Conclusions

A new standardized test meal simplifies the execution of the 13C-octanoic acid breath test, is not influenced by sex or age, has low intra-individual variability, is palatable, does not cause side effects, and is able to evaluate gastric emptying in both patients and healthy controls. Moreover, it can be used in subjects with lactose intolerance, diabetes, and celiac disease.

Introduction

Gastric emptying is a highly coordinated physiological response to the presence of food which can be impaired in several pathological conditions. Since its introduction in clinical practice, scintigraphy has been considered the “gold standard” technique for measuring gastric emptying [1]. However, expensive equipment is needed as well as availability of qualified personnel of a nuclear medicine department. Moreover, scintigraphy induces a significant radiation burden [2] which limits its application in children, fertile women, and subjects undergoing repetitive measurements of gastric emptying in a short period of time. For all these reasons, other non-invasive techniques such as ultrasonography [3], impedance epigastrography [4], applied potential tomography [5], and magnetic resonance [6] have been proposed. In recent years, breath tests with stable isotopes have been developed to reliably assess gastric emptying of both solids (13C-octanoic acid breath test, OBT) [7] and liquids (13C-acetate breath test) [8]. The main advantage of breath test technology is represented by the lack of radiation burden and the worldwide distribution of mass spectrometers used for the diagnosis of H. pylori infection that can also be used for OBT. Moreover, breath tests are non-invasive, non-operator-dependent and can be performed several times in the same subject without biological hazard. A potential drawback of the OBT is the weak correlation obtained in the same subjects between scintigraphy and breath test results [9]. In addition, the absence of a standard meal and accordingly the lack of the normal values reduce the use of OBT for diagnostic purposes.

Aim of this multicenter study was to evaluate both the reference range and the within-subject variability of t1/2 in healthy subjects by means of the OBT with a new gluten-, glucose-, and lactose-free muffin meal with 100 mg of 13C-octanoic acid (EXPIROGer®). The influence of age, sex, and pathological conditions on OBT results was also tested.

Section snippets

Methods

This study was performed on healthy volunteers and patients who gave their informed consent to participate. The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki (6th revision, 2008) as reflected in a priori approval by the human research Committee of each participating Institution.

OBT with the two test meals

The preliminary study recruited 18 healthy volunteers (46 ± 15 years; 10 males, 8 females). A good correlation in t1/2 values was found when evaluated by means of the two test meals (Fig. 1).

OBT with EXPIROGer® in healthy subjects

In the core study, 131 healthy subjects (47 ± 18 years) were enrolled. Of them, 30 (23%) were randomly selected and asked to repeat the OBT in a following day. There were 58 males (31, 14 and 13 in groups A, B, and C) and 73 females (40, 20, and 13 in groups A, B, and C). The t1/2 values were normally

Discussion

Since its introduction in 1993, the 13C-OBT has been proposed as a simple, safe, and repeatable test to evaluate gastric emptying of solids [7]. It provides relevant physiological information on gastric motor function and often confirms the clinical suspicion of dismotility in both functional (“dismotility-like” non-ulcer dyspepsia) and pathological conditions (diabetic gastroparesis, untreated celiac disease, post-gastric surgery dumping or stasis syndrome) [11], [12], [13]. Moreover, it is

Acknowledgement

IGGET Members wish to thank the following people for their useful suggestions:

  • Marchi S., Ninotta M.G.O., Gambaccini D., Cristiani F., Giorgetti L. (Department of Gastroenterology, Gastroenterology Unit, University of Pisa, Italy).

  • Bonfrate L., Campobasso M., De Bari O., De Benedictis P., De Venuto R., Maggipinto A., Persichella R., Ruggero V., Saccotelli I., Tamma V., Berardino M. (Department of Internal Medicine and Public Medicine, University Medical School, Bari, Italy).

  • Petrelli M.

References (20)

There are more references available in the full text version of this article.

Cited by (43)

View all citing articles on Scopus
1

On behalf of the Italian Group for Gastric Emptying Testing (IGGET). IGGET Members are reported in Appendix A.

View full text