Simultaneous measurement of gastric emptying with a simple muffin meal using [13C]octanoate breath test and scintigraphy in normal subjects and patients with dyspeptic symptoms

The objective of this study was to determine how the [¹³C]octanoate breath test (OBT) using a muffin meal correlates with gastric emptying scintigraphy (GES) in normal subjects and patients with dyspeptic symptoms. Ten normal subjects and 23 patients with dyspeptic symptoms underwent simultaneous GES and [¹³C]OBT. After an overnight fast, a muffin labeled with [^99mTc]sulfur colloid and [¹³C]octanoate was ingested along with water labeled with [¹¹¹In]DTPA. Breath samples and scintigraphic images were obtained at baseline and at regular postprandial intervals over 6 hr. In the normal subjects, the mean GES T1/2 of solids and liquids were 64 ± 17 and 55 ± 27 minutes, respectively. The calculated OBT T1/2 using the 6-hr breath collection was 138 ± 15 min and correlated with T1/2 for solids by GES (r = 0.664; P = 0.051), but did not correlate with T1/2 for liquids by GES (r = 0.13; P = 0.738). In dyspeptic patients, the T1/2 for GES was 87 ± 53 min and 81 ± 70 min for solids and liquids, respectively. The mean OBT T1/2 was 155 ± 57 min and correlated with GES T1/2 for solids (r = 0.86; P < 0.001) and GES T1/2 for liquids (r = 0.73; P < 0.001). Delayed gastric emptying (GE) of the muffin meal was identified by scintigraphy in seven patients. The sensitivity and specificity for OBT identifying delayed GE were 86% and 94%. Use of the initial truncated 4-hr OBT results also revealed a significant correlation between OBT and GES T1/2 for solids (r = 0.86; P < 0.001) with sensitivity and specificity for detecting delayed GE of 86% and 94%, respectively. In addition, a linear regression model was able to reduce the number of collection points to four, while maintaining the same sensitivity and specificity. In conclusion, the OBT for GE, using an easily prepared muffin meal, significantly correlates with GES for solids. This muffin-based OBT is a sensitive and specific method to detect delayed GE in dyspeptic patients.