title: A stable isotope breath test with a standard meal for abnormal gastric emptying of solids in the clinic and in research.
abstract: OBJECTIVE
  The aim of this study was to validate a [13C]-Spirulina platensis gastric emptying (GE) breath test (GEBT) with a standardized meal.
  
  
  METHODS
  Thirty-eight healthy volunteers and 129 patients with clinically suspected delayed GE underwent measurements at 45, 90, 120, 150, 180, and 240 minutes after a 238 kcal meal labeled test with 100 mg [13C]-S platensis and 0.5 mCi 99mTc. We established normal ranges for scintigraphy with this test meal, intraindividual and interindividual coefficients of variation (COVs), and the ability of the [13C] GEBT breath percent dose excreted *1000 values to predict scintigraphic half-life and to categorize GE as delayed, normal, or accelerated.
  
  
  RESULTS
  In health, the 10th and 90th percentiles of half-life for scintigraphic GE with this meal were 52 and 86 minutes; intraindividual COVs for scintigraphy and the GEBT were, respectively, 31% and 27% at 45 minutes, 17% and 21% at 90 minutes, 13% and 16% at 120 minutes, 10% and 13% at 150 minutes, and 8% and 12% at 180 minutes. Interindividual COVs at each time for the [13C] GEBT and scintigraphy were typically approximately 1%-4% lower than intraindividual COVs. Individual breath samples at 45, 150, and 180 minutes predicted GE category; at 80% specificity, 45- and 180-minute samples combined were 93% sensitive to identify accelerated GE, and 150- and 180-minute combined were 89% sensitive for delayed GE.
  
  
  CONCLUSIONS
  [13C]-S platensis GEBT is as reproducible as scintigraphy; imprecision with both tests reflects physiologic variation. With 4 breath samples, this method with an off-the-shelf meal is valid to assess GE in clinic and in research.
authors.affiliation: Clinical Enteric Neuroscience Translational and Epidemiological Research, College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA. szarka.lawrence@mayo.edu
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Szarka
authors.forename: Michael
authors.initials: M
authors.lastname: Camilleri
authors.forename: Adrian
authors.initials: A
authors.lastname: Vella
authors.forename: Duane
authors.initials: D
authors.lastname: Burton
authors.forename: Kari
authors.initials: K
authors.lastname: Baxter
authors.forename: Julie
authors.initials: J
authors.lastname: Simonson
authors.forename: Alan R
authors.initials: AR
authors.lastname: Zinsmeister
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes / Q000008:administration & dosage; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D006207:Half-Life; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D053545:Spirulina / Q000378:metabolism; D013272:Stomach Diseases / Q000175:diagnosis*; D013667:Technetium / Q000008:administration & dosage; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D013667:Technetium