Is the ¹⁴C-Triolein Breath Test Useful in the Assessment of Malabsorption in Clinical Practice?

Abstract

A ¹⁴C-triolein breath test was carried out on 49 subjects suffering from chronic pancreatitis or from other digestive diseases, and its results were compared with the daily fecal fat excretion. The ¹⁴CO₂ peak excretion was abnormal in all the subjects with a fecal fat excretion above 14 g/day, whereas individual values of ¹⁴CO₂ peak excretion in subjects without steatorrhea and with a fecal fat excretion ranging from 7.1 to 14 g overlapped. The lowest value observed in patients not suffering from steatorrhea was chosen as the lower normal limit of ¹⁴CO₂ peak excretion. A test sensitivity as high as 64% was attained. The correlation between fecal fat and ¹⁴CO₂ peak excretion was highly significant (r = 0.802; p < 0.0001), and it followed a negative exponential function. Therefore, small variations in the ¹⁴CO₂ peak excretion can be associated with a wide range of fecal fat excretion. Well-compensated diabetes secondary to pancreatitis did not interfere with the results of the test. In conclusion, in our experience this test proved to be a qualitative diagnostic tool with a low sensitivity.

Dose-response relationship between fat ingestion and oxidation: quantitative estimation using whole-body calorimetry and 13C isotope ratio mass spectrometry

“…To determine whether the observed increases in fat oxidation in the studies quoted above were a result of ingested or endogenous fat oxidation, both indirect calorimetry and 13 C tracer methodologies must be used. Some studies have previously used 14 C breath test methodology to determine the extent of malabsorption of some fatty acids in humans (Duncan et al, 1992;Benini et al, 1984;Newcomer et al, 1979). However, these studies did not address questions regarding the contribution of dietary fat to total energy expenditure nor its interaction with other endogenous macronutrients in the post-prandial state.…”

Fat Malabsorption in Cystic Fibrosis: Comparison of Quantitative Fat Assay and a Novel Assay Using Fecal Lauric/Behenic Acid

“…Although the sensitivity of this method has been reported (8) to be as high as 96%, these results have not been reproducible (9,10). Additionally, this test is only a semiquantitative measure with relatively poor specificity (11), thus patients with fat malabsorption identified by this method still need a 72‐hour fat balance study to quantify and confirm this steatorrhea. Another method, the triolein breath test, measures exhaled 14 CO 2 or 13 CO 2 after ingestion of a known amount of triglyceride labeled with 14 C or 13 C. Reports have been mixed as to the sensitivity and specificity of this test, with sensitivity varying from 64% to 100% (12,13).…”

Guidelines for the investigation of chronic diarrhoea, 2nd edition

“…Sensitivities of 85-100% have been reported with specificity >90% using a fat load of about 20 g, 99-101 although lower sensitivity has been reported when faecal fat is only 7-14 g/day (25-50 mmol/day). 102 However, larger fat loads lead to delays in 14 CO 2 excretion and the test procedures are not well standardised. The test is inappropriate in patients with diabetes, liver disease, or obesity.…”