A stable isotope breath test with a standard meal for abnormal gastric emptying of solids in the clinic and in research.
Level 3 - non-randomized controlled study
Prospective cross-sectional diagnostic validation study comparing a breath test to the scintigraphic reference standard.
PubMed 18406670 · doi:10.1016/j.cgh.2008.01.009
What was done
Researchers validated a solid-phase [13C]-Spirulina platensis gastric emptying breath test against 99mTc scintigraphy. Thirty-eight healthy volunteers and 129 patients with suspected delayed gastric emptying consumed a standardized 238 kcal test meal labeled with 100 mg [13C]-S platensis and 0.5 mCi 99mTc. Simultaneous breath and scintigraphy measurements were collected at 45, 90, 120, 150, 180, and 240 minutes to establish reference ranges, coefficients of variation (COVs), and diagnostic accuracy for classifying gastric emptying as delayed, normal, or accelerated.
What was found
In healthy participants, normal scintigraphic half-life (10th to 90th percentile) was 52 to 86 minutes. Intraindividual COVs for scintigraphy versus the breath test were 31% versus 27% at 45 minutes, 17% versus 21% at 90 minutes, 13% versus 16% at 120 minutes, 10% versus 13% at 150 minutes, and 8% versus 12% at 180 minutes. Interindividual COVs were typically 1% to 4% lower than intraindividual COVs. At a fixed 80% specificity, combined breath samples at 45 and 180 minutes yielded 93% sensitivity for accelerated gastric emptying, whereas combined 150- and 180-minute samples yielded 89% sensitivity for delayed gastric emptying.
Why it matters
The [13C]-Spirulina breath test offers a standardized, non-radioactive alternative to scintigraphy that can accurately categorize solid gastric emptying using four timed breath samples with an off-the-shelf meal.
Limits
The abstract does not report confidence intervals for sensitivity and specificity estimates. The specificity threshold was pre-fixed at 80% rather than optimized, which may leave false positives. Results represent a single-center validation, and clinical outcomes resulting from breath-test guided management were not assessed.
Cited by
- contradicts It takes at least five hours for the human stomach to digest a meal after eating.