Measurement of gastric emptying by radiopaque markers in patients with diabetes: correlation with scintigraphy and upper gastrointestinal symptoms

BACKGROUND: Scintigraphy, the gold standard to measure gastric emptying, is expensive and not widely available. Therefore, we compared emptying of radiopaque markers (ROM) from the stomach, by use of fluoroscopy, with scintigraphy in patients with insulin-treated diabetes. METHODS: On the same day we measured gastric emptying of 20 ROM using fluoroscopy and scintigraphic emptying of a standard solid meal. The subjects also completed a validated gastrointestinal (GI) symptom questionnaire. KEY RESULTS: We included 115 patients with insulin-treated diabetes (median age 53, range 21-69 years; 59 women). A moderately strong correlation was demonstrated between scintigraphic (% retained at 2 h) and ROM emptying (markers retained at 6 h) (r = 0.47; P < 0.0001). Eighty-three patients had delayed gastric emptying with scintigraphy, whereas only 29 patients had delayed emptying of ROM. Of the 29 patients with delayed emptying of ROM, 28 also had delayed scintigraphic emptying. The sensitivity and specificity of the ROM test was 34% and 97%, respectively. Significant correlations were only noted between scintigraphic gastric emptying and GI symptom severity, with the strongest correlations for fullness/early satiety (r = 0.34; P < 0.001) and nausea/vomiting (r = 0.30; P < 0.001). CONCLUSIONS & INFERENCES: A gastric emptying test with ROM is a widely available screening method to detect delayed gastric emptying in patients with diabetes, where a positive result seems reliable. However, a normal ROM test does not exclude delayed gastric emptying, and if the clinical suspicion of gastroparesis remains, scintigraphy should be performed. Results from scintigraphy also correlate with GI symptom severity, which ROM test did not.