Abbreviated C13-mixed triglyceride breath test for detection of pancreatic exocrine insufficiency performs equally as standard 5-hour test in patients after gastrectomy performed for gastric cancer

Abbreviated breath test

Abstract

Abstract

Background: ¹³C-mixed triglyceride breath test (¹³C-MTGT) is a non-invasive test for the detection of moderate and severe pancreatic exocrine insufficiency (PEI), but it requires prolonged breath sampling. The aim of this study was to determine the diagnostic power of abbreviated ¹³C-MTGT in detecting PEI in patients after subtotal and total gastrectomy performed due to gastric cancer.

Methods: This cross-sectional observational study included 3 groups of subjects; healthy controls, patients with subtotal and patients with total gastrectomy. Demographic and clinical data of patients were collected. Stool samples to determine faecal elastase (Fe-1) and chymotrypsin were collected and measured by ELISA. All subjects performed 5-hour ¹³C-MTGT breath test. The concentration and relative content of ¹³C in exhaled air was measured by isotope ratio mass spectrometer (IRMS). PEI was confirmed as values of ¹³C-exhalation <26.8% after 5 hours.

Results: Overall, 65 participants were included into analysis, 22 having PEI (n=11 after subtotal and n=11 after total gastrectomy, both performed for gastric cancer). ¹³C-MTGT breath test showed difference in percent of exhaled ¹³C between PEI and non-PEI patients already after 60 minutes (p=0.034). Receiver operating characteristic (ROC) curve analysis showed that cut-off value of 13.74% after 150 minutes is showing equivalent diagnostic power to the longer test with sensitivity and specificity both above 90% for the exclusion of PEI in patients after subtotal and/or total gastrectomy.

Conclusion: In this study abbreviated ¹³C-MTGT test could be shortened from 5 to 2.5 hours without decrease in its diagnostic accuracy for detection of PEI in patients with subtotal or total gastrectomy performed for gastric cancer. This allows significant time savings in the diagnostics of PEI in this subgroup of patients.

Key words: abbreviated ¹³C-mixed triglyceride breath test, pancreatic exocrine insufficiency, gastrectomy, fecal elastase, gastric cancer

Skrajšani dihalni test z mešanimi trigliceridi C¹³ je pri  odkrivanju eksokrine insuficience trebušne slinavke enako natančen kot standardni 5-urni test pri bolnikih po gastrektomiji zaradi raka želodca

IZVLEČEK:

Izhodišče: dihalni test z mešanimi trigliceridi C¹³ (C¹³-MTGT) je neinvaziven test za odkrivanje zmerne in hude eksokrine insuficience trebušne slinavke (PEI), vendar je potrebno dolgotrajno vzorčenje izdihanega zraka. Namen te študije je ugotoviti diagnostično moč skrajšanega C¹³-MTGT pri odkrivanju PEI pri bolnikih po subtotalni in totalni gastrektomiji, opravljeni zaradi raka želodca.

Metode: Ta presečna opazovalna študija je vključevala 3 skupine preiskovancev; zdrave kontrole, bolnike po subtotalni in bolnike po totalni gastrektomiji zaradi karcinoma želodca. Zbrani so bili demografski in klinični podatki bolnikov. Vzorce blata za določanje fekalne elastaze (Fe-1) in kimotripsina smo izmerili z ELISA. Vsi preiskovanci so opravili 5-urni dihalni test C¹³-MTGT. Koncentracijo in relativno vsebnost C¹³ v izdihanem zraku smo izmerili z masnim spektrometrom za razmerje izotopov (IRMS). PEI smo potrdili kot vrednosti C¹³-izdiha <26,8 % po 5 urah.

Rezultati: Skupno je bilo v analizo vključenih 65 udeležencev, 22 jih je imelo PEI (n=11 po subtotalni gastrektomiji in n=11 po totalni gastrektomiji). C¹³-MTGT dihalni test je pokazal razliko v odstotkih izdihanega C¹³ med bolniki s PEI in bolniki brez PEI že po 60 minutah (p=0,034). Analiza krivulje karakteristike delovanja sprejemnika (ROC) je pokazala, da mejna vrednost 13,74 % po 150 minutah kaže enakovredno diagnostično moč daljšemu testu z občutljivostjo in specifičnostjo nad 90 % za izključitev PEI pri bolnikih po subtotalni ali totalni gastrektomiji..

Zaključek: Ta študija je pokazala, da skrajšanje C¹³-MTGT s 5 na 2,5 ure ne zmanjša njegove diagnostične natančnosti za odkrivanje PEI pri bolnikih po subtotalni ali totalni gastrektomiji, opravljeni zaradi raka želodca. To lahko omogoča znatne prihranke časa pri diagnostiki PEI pri tej podskupini bolnikov.

Ključne besede: skrajšani C¹³ - mešani trigliceridni dihalni test, eksokrina insuficienca trebušne slinavke, gastrektomija, fekalna elastaza, rak želodca