Engelen MPKJ, Com G, Anderson PJ, Deutz NEP. New stable isotope method to measure protein digestibility and response to pancreatic enzyme intake in cystic fibrosis.
Clin Nutr 2013;
33:1024-32. [PMID:
24268783 DOI:
10.1016/j.clnu.2013.11.004]
[Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 10/25/2013] [Accepted: 11/02/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND & AIMS
Adequate protein intake and digestion are necessary to prevent muscle wasting in cystic fibrosis (CF). Accurate and easy-to-use methodology to quantify protein maldigestion is lacking in CF.
OBJECTIVE
To measure protein digestibility and the response to pancreatic enzyme intake in CF by using a new stable isotope methodology.
DESIGN
In 19 CF and 8 healthy subjects, protein digestibility was quantified during continuous (sip) feeding for 6 h by adding (15)N-labeled spirulina protein and L-[ring-(2)H5]phenylalanine (PHE) to the nutrition and measuring plasma ratio [(15)N]PHE to [(2)H5]PHE. Pancreatic enzymes were ingested after 2 h in CF and the response in protein digestibility was assessed. To exclude difference in mucosal function, postabsorptive whole-body citrulline (CIT) production rate was measured by L-[5-(13)C-5,5-(2)H2]-CIT pulse and blood samples were taken to analyze tracer-tracee ratios.
RESULTS
Protein digestibility was severely reduced in the CF group (47% of healthy subjects; P < 0.001). Intake of pancreatic enzymes induced a slow increase in protein digestibility in CF until 90% of values obtained by healthy subjects. Maximal digestibility was reached at 100 min and maintained for 80 min. Stratification into CF children (n = 10) and adults showed comparable values for protein digestibility and similar kinetic responses to pancreatic enzyme intake. Whole-body citrulline production was elevated in CF indicating preserved mucosal function.
CONCLUSION
Protein digestibility is severely compromised in patients with CF as measured by this novel and easy-to-use stable isotope approach. Pancreatic enzymes are able to normalize protein digestibility in CF, albeit with a severe delay. Registration ClinicalTrials.gov = NCT01494909.
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