The ¹³C‐mixed triglyceride breath test in healthy adults: determinants of the ¹³CO₂ response

Abstract

Defects in lipolysis due to pancreatic insufficiency can be diagnosed by the mixed triglyceride (MTG) 13CO2 breath test. However, the effects of various test conditions on the 13CO2 response have only been partially elucidated. In healthy adults, we performed the 13CO2 mixed triglyceride breath test and we compared (a) the inter- and intra-individual variation in the 13CO2 response; (b) the effect of two different test meals; (c) the effect of an additional meal during the test; and (d) the effect of physical exercise during the test. Upon repeating the test in the same individual (test meal cream), repeatability coefficients were large, with respect to either time to maximum 13C excretion rate (3.8 h). maximum 13C excretion rate (4.9% 13C dose h-1) or cumulative recovery of 13C over the 9-h study period (22.7% 13C dose). The cumulative 13C expiration over 9 h obtained with the test meal composed of cream was quantitatively similar to that obtained with bread and butter: 42.2 +/- 8.4% and 47.7 +/- 6.3% respectively. Fasting for 9 h during the test resulted in similar 13C expiration rates and cumulative 13C expiration (43.4% +/- 7.2%) when compared with consumption of an additional meal 3 h after the start of the test (38.3 +/- 5.3%). The 13CO2 response increased in five out of seven subjects, but decreased in the other two, when moderate exercise was performed (bicycle ergometer, 50 W for 5 h). We conclude that the repeatability of the MTG test in healthy adults is low. The present results indicate that a solid and a liquid test meal, containing a similar amount of fats, give similar cumulative 13CO2 responses, and that stringent prolonged fasting during the test is unnecessary. Standardization of physical activity seems preferable, since the unequivocal effects of moderate exercise on the 13CO2 response were observed in the individuals studied.

Sensitivity and specificity of an abbreviated 13 C‐mixed triglyceride breath test for measurement of pancreatic exocrine function

“…3 The standard parameter for evaluation of pancreatic exocrine function using this test is the cumulative 13 C-exhalation over the 6 hrs following a test meal. To avoid an increase in overall CO 2 -production that also influences 13 CO 2 -exhalation, subjects need to remain seated during the test procedures 18 ; thus, although the 13 C-MTGT is a rather convenient, noninvasive indirect pancreatic function test, the long period of breath sampling and immobilization is a major drawback for clinical application, so shorter test versions would be highly desirable. The clinical need for such a test is underlined by the fact that current multinational research agendas explicitly aim to simplify the 13 C-MTGT and so this study has been performed as part of the HaPanEU project (Harmonizing diagnosis and therapy of pancreatitis across Europe).…”

Fat malabsorption in cystic fibrosis patients receiving enzyme replacement therapy is due to impaired intestinal uptake of long-chain fatty acids

“…End expiratory breath was collected with a straw into a 10-mL tube (Exetainers; Labco Limited, High Wycombe, United Kingdom) from which aliquots were taken to determine 13 C enrichment with a continuous-flow isotope ratio mass spectrometer (Finnigan Breath MAT; Finnigan MAT GmbH, Bremen, Germany) in conformance with previous experiments (24). The abundance of 13 C in breath carbon dioxide was expressed as the difference per milliliter from the reference standard Pee Dee Belemnite limestone (‰).…”

“…The recovery of expired 13 CO 2 in the present study was similar to that obtained in other studies, indicating that the CF patients were sufficiently supplemented with pancreatic enzymes. In healthy adults, the 6-h cumulative percentage of expired 13 C after ingestion of [ 13 C]MTG varied between 23% and 52% of the dose in one study (23) and between 3% and 48% in another study (24). The recovery of expired 13 CO 2 in CF patients receiving regular amounts of pancreatic enzymes varied between 0% and 45% (23, 25).…”

Update on diagnostic value of breath test in gastrointestinal and liver diseases

“…The thoroughly investigated triglyceride BT is the "mixed" triglyceride test using 1,3distearyl, 2[13Ccarboxyl] octanoyl glycerol; demonstrating a sensitivity and specificity of 89% and 81% respectively [56] . Literature review recommends 200300 mg of the mixed triglycerides is the predominantly used doses for adults (15 mg/kg body weight for children).…”

“…Advent of Bench top analyzers and point of care testing will further pave the way for utilization of breath testing, leading to rapid production of results. Future development is aimed at development of specific sensor based hand Glucose hydrogen breath test SIBO 62% and 83% [7] Lactulose hydrogen breath test SIBO 31% and 86% [5] 13C-glycocholate breath test SIBO 76% and 33% [69] 13C-xylose breath test SIBO 89% and 30% [69] Fructose hydrogen breath test Carbohydrate malabsorption 98% and 86% [65] Lactose hydrogen breath test Carbohydrate malabsorption 80% and 100% [66] 13C-lactose breath test Carbohydrate malabsorption 84% and 96% [70] 13C-urea breath test H. pylori infection 96% and 93% [39] 13C-aminopyrine breath test Evaluation of liver function 85.7% and 67.5% [58] 13C-methacetin breath test Evaluation of liver function 92.6% and 94.1% [67] 13C-phenacetin breath test Evaluation of liver function 98% and 60% [68] 13C-mixed triglycerides breath test Evaluation of exocrine pancreatic insufficiency 89% and 81% [56] 13C-octanoic acid breath test Assessment of gastric emptying 67% and 80% [71] SIBO: Small intestinal bacterial overgrowth; 13C: 13 carbon.…”