Gastric emptying: methodology and normal ranges for two commonly used meals in the UK.
Level 3 - non-randomized controlled study
Prospective within-subject comparative study establishing normative reference values in healthy volunteers
PubMed 32427698 · doi:10.1097/MNM.0000000000001209
What was done
Forty-two healthy volunteers (20 men, 22 women; aged 22–68 years) without gastrointestinal symptoms or diabetes underwent gastric emptying scintigraphy after an overnight fast on two separate days. Participants consumed two radiolabelled (10 MBq Tc-DTPA) test meals: a standardized scrambled egg sandwich (scrambled eggs with two slices of bread) and gluten-free porridge (40 g oats in 200 mL whole milk). Anterior-posterior static images were taken standing every 5 minutes for 2 hours, plus a single image at 3 hours. Data were fitted to a power-exponential model to calculate lag time, half-emptying time, peak emptying rate, time-to-peak emptying, exponential half-life, and 3-hour retention percentage. Meals were compared using paired t-tests, sex differences using two-sample t-tests, and age/body surface area associations using linear regression.
What was found
All functional gastric emptying parameters differed significantly between the two meals (P < 0.001). Normal ranges were: - Lag time: 0–13 min for porridge vs 1–34 min for scrambled egg - Half-emptying time: 18–73 min for porridge vs 44–116 min for scrambled egg - Exponential half-life: 21–57 min for porridge vs 20–82 min for scrambled egg - 3-hour retention: <7% for porridge vs <17% for scrambled egg Sex differences showed only weak statistical trends (0.05 < P < 0.10), as did correlations between select parameters and age or body surface area (0.05 < P < 0.10).
Why it matters
Standardization of gastric emptying scintigraphy in the UK has been hindered by protocol variation. These findings provide meal-specific reference ranges, showing porridge empties substantially faster than egg sandwiches and cannot be used interchangeably without adjusted diagnostic cutoffs.
Limits
The sample size was modest (n = 42) and drawn from a single center. The cohort included only healthy volunteers, so diagnostic performance and threshold sensitivity were not evaluated in symptomatic patient populations. The reference intervals are specific to the exact meal compositions and imaging schedules used.
Cited by
- contradicts It takes at least five hours for the human stomach to digest a meal after eating.