Performance characteristics of scintigraphic measurement of gastric emptying of solids in healthy participants

Abstract

Background Gastric emptying (GE) is measured in pharmacodynamic and diagnostic studies. Aims To assess inter- and intra-subject coefficients of variation (COV) of scintigraphic GE measurements in healthy subjects, and associations of GE with gender and BMI. Methods Data from participants with scintigraphic measurements of gastric emptying of solids were analyzed. Primary endpoints were gastric emptying T1/2 (GE T1/2) and GE at 1, 2, 3 and 4 hours. Results The patient cohort consisted of 105 males and 214 females; at least 2 studies were performed in 47 subjects [16 males (M), 32 females (F)]. Inter-subject COV (COVinter) for GE T1/2 were similar in M and F: overall 24.5% (M 26.0%, F 22.5%); COV are predictably lowest for GE at 4h (COVinter 9.6%). COVintra for T1/2 and GE4h were overall 23.8% and 12.6%, and were similar to COVinter values. Gender (but not age or body mass index [BMI]) was significantly associated with GE T1/2 [p<0.001, F 127.6 ± 28.7 (SD) min; M 109.9 ± 28.6 min] and with GE at 1h and 2h. Repeat GE T1/2 values in 47 participants were significantly correlated (r= 0.459, p<0.001) with median difference of −6 min (mean −1.6, range −56 to 72 min). Bland-Altman plots showed Δ GE T1/2 similarly distributed across mean GE T1/2 100–155 minutes, and across studies conducted 90 to 600 days apart. Conclusion Inter-subject variations in scintigraphic GE results are only slightly higher than the intra-subject measurements, which are also reproducible over time in healthy volunteers. Gender, but not BMI, is significantly associated with GE results.

Novel and Validated Approaches for Gastric Emptying Scintigraphy in Patients with Suspected Gastroparesis

“…Similarly, others have shown greater sensitivity of detection of abnormal GE with use of [5]. Conversely, the COV inter and COV intra for GE T 1/2 with the 296 kcal, 32 % fat meal were both *25 % [4], suggesting that a single observation of GE T 1/2 could only be useful as a screen for gastroparesis if the GE T 1/2 is[150 min (since the median and mean values in 319 patients were 120 and 121.7 min, respectively).…”

“…Diagnostic interpretation of GE T 1/2 by GES in an individual patient requires robust definition of the intra-individual COV with the specific meal used. Thus, the estimated COV inter for GE T 1/2 was 25 % with the EggBeaters meal and 24 % using a meal of higher fat and calorie content [4] in which the solid phase is radiolabeled. With the latter radiolabeled solid meal, the COV inter for GE at 4 h was 9.6 %, confirming the recommendation by Tougas et al [1] that the percent retention at 4 h is an endpoint useful for gastroparesis screening.…”

“…Such a test meal with two eggs, 296 kcal, and 32 % fat content has been extensively validated in the literature, including detailed performance characteristics in large healthy populations [4], responsiveness to treatment with pharmacological agents [9,10], and demonstrated utility in the clinical practice of three Mayo Clinic sites for over two decades. These studies also demonstrated that the gastrointestinal tract of healthy females empties on average 15 % slower than males [4], an observation that should be factored into the interpretation of GE data.…”

“…Gastric emptying curves for liquid and solid meals were derived based on data from the available literature (references 1, 2, 4, 5, and 6 in the paper) healthy individuals should inform future investigations regarding whether the EggBeaters meal is optimal for the assessment of GE in patients with upper gastrointestinal symptoms. While the Ensure Plus meal may be useful in conducting GES in patients unable to tolerate a solid meal, the published validation data [4] and responsiveness to pharmacological therapy [9,10] suggest that an alternative meal of higher caloric and fat content should be used to assess GE in the majority of patients with upper gastrointestinal symptoms.…”

Regional Colonic Transit Pattern Does Not Conclusively Identify Evacuation Disorders in Constipated Patients with Delayed Colonic Transit

“…13 Abdominal images of 2-minute duration were obtained with anterior and posterior gamma cameras following ingestion of the 99m Tc-labeled egg meal (296 kcal, 32% fat) and 1, 2, and 4 hour (GE 1 hr, GE 2 hr, and GE 4 hr) clinical studies. Orocecal transit was assessed by the colonic filling of 99m Tc-labeled egg meal at 6 hours.…”