The Gastric Emptying Study with Oatmeal: Reference Range and Reproducibility as a Function of Age and Sex

Abstract

This study evaluated the reference range and reproducibility of the gastric emptying study with oatmeal as a function of age and sex. Methods: Twenty-four healthy subjects, 12 men and 12 women, categorized into 3 age groups, 20-40, 40-60, and 60-80 y, were studied twice, 1 d apart, with instant oatmeal labeled with 99m Tc-sulfur colloid. Imaging was performed in the upright position using the left anterior oblique (LAO), right posterior oblique (RPO), anterior, and posterior projections. One-minute digital images acquired every 15 min for 60 min were used to calculate a simple half-time of emptying. Results: A strong correlation was found among half-times of gastric emptying calculated from the anterior projection, LAO projection, anterior-posterior geometric mean, and LAO-RPO geometric mean (P , 0.01). A significant inverse correlation was found between increasing age and decreasing half-time of emptying in men and women (P , 0.05). A reference range of 10-60 min is suggested for 20-to 40-y-old patients, 10-40 min for 40-to 60-y-olds, and 10-30 min for 60-to 80-y-olds. Halftimes of emptying tended to be longer for women than for men (not statistically significant). There was a large variation between the first and second studies, with a trend toward decreasing variation with increasing age in both men and women. In repeated studies, a reference range of variation of up to 30 min is suggested for 20-to 40-y-old patients, up to 20 min for 40-to 60-y-olds, and up to 15 min for 60-to 80-yolds. Conclusion: The reference range for half-time of gastric emptying with instant oatmeal decreases with increasing age in both men and women. Test-retest variation is relatively large and tends to decrease with increasing age in both men and women. Data from either the LAO projection or the anteriorposterior geometric mean are acceptable for calculating the half-time of gastric emptying.

Update on Gastrointestinal Radiopharmaceuticals and Dosimetry Estimates

“…There has been a resurgence in popularity of an oatmeal test meal for gastric emptying studies(7, 8). Reconstituted instant oatmeal provides a semi-solid meal rather than a solid meal, because it does not require trituration prior to emptying.…”

“…It is convenient to prepare and palatable to a large number of subjects. One reported oatmeal test meal(7) labeled with 99m Tc-SC has a caloric content of 100 kcal and contains 2 g of fat, 4 g of protein, and 19 g of carbohydrate. Some centers employ a meal consisting of pancakes which are prepared from a mix into which water and 99m Tc-SC are incorporated prior to cooking on a griddle(9).…”

“…Both meals were evaluated for radiolabel stability, and appeared to be stable although they were tested in diluted acid (not gastric fluid). A recent evaluation(6) of 99m Tc-SC-labeled instant oatmeal in human gastric fluid suggested that it is not adequately stable; however, it is not clear whether different methods of preparation of instant oatmeal had an effect (simple mixing with hot water(6) or microwave cooking after adding tracer(7)), or whether the technique of separating oatmeal particles from radiocolloid is really relevant if they empty together from the stomach.…”

“…In addition to the target organs, the EDE is reported. The normal transit times for stomach were assumed to be 1.42 h for solids(2), 0.44 h for semisolid (oatmeal)(7) and 0.35 h for liquids; normal transit half-times for small intestine, upper large intestine and lower large intestine were assumed to be 4 h, 10 h and 18 h, respectively(29, 31). Physical decay of the radiolabel was also considered in the model.…”

Normal values and symptom correlation of a simplified oatmeal‐based gastric emptying study in the Chinese population

“…7,8 In that study, images were acquired in the upright position at 0, 1, 2, and 4 h after meal ingestion; gastric retention of > 10% at 4 h is indicative of delayed emptying. [13][14][15][16][17] Since instant oatmeal is more palatable and widely commercialized, we hypothesized that it may serve as a practical and reliable test meal for gastric emptying studies. [9][10][11][12] In addition, a significant portion of patients in many Asian societies cannot eat egg-containing food due to religious or health reasons (i.e.…”