Significance of diagnostic parameters in [C-13]octanoic acid gastric emptying breath tests

Two novel characteristic parameters, the latency time (t(lat)) and the asce nsion time (t(asc)) are proposed for evaluation of non-invasive [C-13]octan oic acid breath tests for assessment of the gastric emptying of solids. In breath tests performed in control subjects (n = 30) and diabetic patients ( n = 100), the usefulness of these parameters was compared to conventional p arameters, i.e,, gastric half emptying-time (t(1/2,b)) and lag phase (t(lag ,b)). The proposed parameters were only loosely correlated (controls, r = 0 .199; diabetics, 0.616). A strong correlation was found between the convent ional parameters (controls, r = 0.891; diabetics, r = 0.962). Based on the conventional method, 36 patients were suspicious of delayed gastric emptyin g including 24 patients which exhibited a simultaneous delay in both parame ters. Using the new parameters, a total of 46 patients were suspicious of d elayed gastric emptying with 15 and 20 having isolated delay in t(lat) and t(asc), respectively. We conclude that the novel parameters may be more app ropriate for examination of the different phases of gastric emptying and fo r evaluation of gastric emptying disturbances in diabetic patients than the parameters conventionally used for this purpose.