title: Sensitivity and specificity of an abbreviated (13)C-mixed triglyceride breath test for measurement of pancreatic exocrine function.
abstract: BACKGROUND
  A modified (13)C-mixed triglyceride breath test ((13)C -MTGT) detects moderate pancreatic exocrine insufficiency noninvasively and reliably, but it requires prolonged breath sampling (6 hours (hr)).
  
  
  OBJECTIVE
  We aimed to investigate whether (13)C -MTGT can be abbreviated, to optimize clinical usability.
  
  
  METHODS
  We analyzed the (13)C-MTGT of 200 consecutive patients, retrospectively. Cumulative 1-5 hr (13)C-exhalation values were compared with the standard parameter (6-hr cumulative (13)C-exhalation). We determined the sensitivity and specificity of shortened breath sampling periods, by comparison with the normal values from 10 healthy volunteers, whom also underwent a secretin test to quantitate pancreatic secretion. Moreover, we evaluated the influence of gastric emptying (GE), using a (13)C-octanoic acid breath test in a subset (N = 117).
  
  
  RESULTS
  The 1-5 hr cumulative (13)C-exhalation tests correlated highly and significantly with the standard parameter (p < 0.0001). Sensitivity for detection of impaired lipolysis was high (≥77%), but the specificity was low (≥38%) for the early measurements. Both parameters were high after 4 hrs (88% and 94%, respectively) and 5 hrs (98% and 91%, respectively). Multivariate linear correlation analysis confirmed that GE strongly influenced early postprandial (13)C-exhalation during the (13)C-MTGT.
  
  
  CONCLUSIONS
  Shortening of the (13)C -MTGT from 6 to 4 hrs of duration was associated with similar diagnostic accuracy, yet increased clinical usability. The influence of GE on early postprandial results of the (13)C-MTGT precluded further abbreviation of the test.
authors.affiliation: Department of Internal Medicine, Israelitic Hospital, University of Hamburg, Hamburg, Germany.
authors.forename: Jutta
authors.initials: J
authors.lastname: Keller
authors.affiliation: Department of Internal Medicine, Israelitic Hospital, University of Hamburg, Hamburg, Germany.
authors.forename: Viola
authors.initials: V
authors.lastname: Meier
authors.affiliation: Department of Internal Medicine, Israelitic Hospital, University of Hamburg, Hamburg, Germany.
authors.forename: Kristina U
authors.initials: KU
authors.lastname: Wolfram
authors.affiliation: Department of Internal Medicine, Israelitic Hospital, University of Hamburg, Hamburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Rosien
authors.affiliation: Department of Internal Medicine, Israelitic Hospital, University of Hamburg, Hamburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Layer
keywords: Breath test; diagnostic testing; gastric emptying; lipolysis; mixed triglyceride breath test; optimization; pancreatic disease; pancreatic function
references.citation: J Clin Chem Clin Biochem. 1989 Feb;27(2):103-13
references.pmid: 2787387
references.citation: Z Gastroenterol. 2004 Oct;42(10):1117-28
references.pmid: 15508057
references.citation: Clin Gastroenterol Hepatol. 2007 Apr;5(4):484-8
references.pmid: 17445754
references.citation: Eur J Gastroenterol Hepatol. 2000 Jan;12(1):85-91
references.pmid: 10656216
references.citation: Eur J Clin Invest. 1997 May;27(5):434-42
references.pmid: 9179552
references.citation: United European Gastroenterol J. 2013 Apr;1(2):79-83
references.pmid: 24917944
references.citation: Z Gastroenterol. 2012 Nov;50(11):1176-224
references.pmid: 23150111
references.citation: Gastroenterology. 1989 Apr;96(4):1126-34
references.pmid: 2494097
references.citation: Can J Biochem Physiol. 1959 Dec;37:1393-9
references.pmid: 14405350
references.citation: Pancreas. 2011 Nov;40(8):1201-5
references.pmid: 21705945
references.citation: Gastroenterology. 1993 Jun;104(6):1640-7
references.pmid: 8500721
references.citation: Pancreas. 2014 Aug;43(6):842-8
references.pmid: 24763073
references.citation: Neurogastroenterol Motil. 2009 Oct;21(10):1039-e83
references.pmid: 19549136
references.citation: Clin Chem. 1985 Jan;31(1):14-9
references.pmid: 3871178
references.citation: Scand J Gastroenterol. 1998 Mar;33(3):327-34
references.pmid: 9548629
references.citation: Scand J Gastroenterol. 1999 Nov;34(11):1153-6
references.pmid: 10582768