SIMULTANEOUS ASSESSMENTS OF EXOCRINE PANCREATIC FUNCTION BY CHOLESTERYL-[C-14]OCTANOATE BREATH TEST AND MEASUREMENT OF PLASMA P-AMINOBENZOIC ACID

Two noninvasive tests for assessing pancreatic exocrine function, the cholesteryl-[C-14]octanoate breath test and the HPLC N-benzoyl-tyrosyl -p-aminobenzoic acid/p-aminosalicylic acid (NBT-PABA/PAS) test, were s imultaneously performed in nine patients with pancreatic exocrine insu fficiency due to chronic pancreatitis and in nine healthy volunteers. (CO2)-C-14 output in breath and plasma PABA concentration rose slowly in patients but increased rapidly in healthy subjects. The measurement time giving the best discrimination between both groups was 120 min f or the cholesteryl-[C-14]octanoate breath test and 90 min for the plas ma PABA test. At these points, both single-sample tests had essentiall y identical diagnostic sensitivity. The diagnostic sensitivities of th e two single-sample tests were equal to that of the cumulative 6-h uri nary PABA recovery and the cumulative 6-h urinary PABA/PAS ratio. We c onclude that, for both the cholesteryl-[C-14]octanoate breath test and the plasma PABA test, a single test sample is sufficient for rapid de tection of impaired exocrine pancreatic function.