title: Calcium carbonate breath test for non-invasive estimation of gastric acid secretion.
abstract: Gastric acid measurement is useful in assessing the effectiveness of antisecretory drugs, however, the conventional tests involve invasive nasogastric intubation. Orally administered ¹³C-labeled calcium carbonate (Ca¹³CO₃) reacts with gastric acid to produce ¹³C-labeled carbon dioxide (¹³CO₂), which is then excreted in the breath. The objective of this study was to evaluate the suitability of Ca¹³CO3 breath test for estimating gastric acid secretion in human noninvasively. First, the Ca¹³CO₃ breath test and the measurement of pooled gastric acid under a fasting condition were performed in 6 healthy volunteers to evaluate the correlation between the two parameters. Next, endoscopic gastric acid collection and the Ca¹³CO₃ breath test were performed on different days after pentagastrin injection in 20 subjects to evaluate the correlation between the tests and the reproducibility. Finally, the same studies were repeated in 4 subjects before and after 1-week rabeprazole, a proton pump inhibitor, administration. The maximum CO₂ concentration (Cmax) correlated very well with the amount of pooled gastric acid (r = 0.95), suggesting that Ca¹³CO₃ breath test values well reflected the fasting intragastric acidity. The ¹³CO₂ concentration after pentagastrin injection correlated well with pentagastrin-stimulated maximal acid output (r = 0.79 at 20 min). The reproducibility of the Ca¹³CO₃ breath test under pentagastrin-stimulation was good (coefficient of variation = 0.11). Rabeprazole administration markedly reduced the values of the Ca¹³CO₃ breath test, suggesting that it can sensitively assess the efficacy of rabeprazole. The Ca¹³CO₃ breath test can potentially be a useful method for non-invasive estimation for gastric acid secretion in human.
authors.affiliation: Division of Gastroenterology, Tohoku University Graduate School of Medicine.
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Shinkai
authors.forename: Katsunori
authors.initials: K
authors.lastname: Iijima
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Koike
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Maejima
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Endo
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Ara
authors.forename: Naoki
authors.initials: N
authors.lastname: Asano
authors.forename: Akira
authors.initials: A
authors.lastname: Imatani
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ohara
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D001944:Breath Tests / Q000379:methods*; D002119:Calcium Carbonate / Q000008:administration & dosage / Q000378:metabolism; D002247:Carbon Isotopes / Q000008:administration & dosage / Q000378:metabolism; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D006801:Humans; D016014:Linear Models; D010418:Pentagastrin / Q000494:pharmacology; D054328:Proton Pump Inhibitors / Q000494:pharmacology; D064750:Rabeprazole / Q000494:pharmacology; D013055:Spectrophotometry, Infrared
chemical_list: D002247:Carbon Isotopes; D054328:Proton Pump Inhibitors; D064750:Rabeprazole; D010418:Pentagastrin; D002119:Calcium Carbonate