Dietary Aromatic Amino Acid Requirements During Early and Late Gestation in Healthy Pregnant Women.
amino acid requirements
indicator amino acid oxidation
phenylalanine
pregnancy
stable isotopes
tyrosine
Journal
The Journal of nutrition
ISSN: 1541-6100
Titre abrégé: J Nutr
Pays: United States
ID NLM: 0404243
Informations de publication
Date de publication:
10 12 2020
10 12 2020
Historique:
received:
19
06
2020
revised:
07
08
2020
accepted:
22
09
2020
pubmed:
15
11
2020
medline:
28
1
2021
entrez:
14
11
2020
Statut:
ppublish
Résumé
Phenylalanine and tyrosine (referred to as total aromatic amino acids; TAAs) are essential for protein synthesis, and are precursors for important catecholamines. Current estimated average requirement (EAR) recommendations for TAA during pregnancy are 36 mg·kg-1·d-1, and has not been experimentally determined. The aim was to determine TAA requirements (dietary phenylalanine in the absence of tyrosine) during early and late gestation using the indicator amino acid oxidation (IAAO, with L-[1-13C]leucine) technique. Nineteen healthy pregnant women (age 22-38 y) were studied at a range of phenylalanine intakes (5 to 100 mg·kg-1·d-1) in early (13-19 wk) and/or late (33-39 wk) pregnancy for a total of 51 study days. Graded test intakes were provided as 8 hourly isonitrogenous and isocaloric meals. Breath samples were collected for 13C enrichment analysis on an isotope ratio mass spectrometer. A plasma sample was collected and analyzed for phenylalanine and tyrosine concentrations on an amino acid analyzer. The TAA requirement in early and late pregnancy was calculated using 2-phase linear regression crossover analysis that identified breakpoints in 13CO2 production (the requirement) in response to phenylalanine intakes. TAA requirement during early pregnancy was 44 mg·kg-1·d-1 (95% CI: 28.3, 58.8) and during late pregnancy was 50 mg·kg-1·d-1 (95% CI: 36.1, 63.1). In early and late pregnancy, plasma phenylalanine and tyrosine concentrations rose linearly in response to graded phenylalanine intakes. Our results suggest that the current EAR of 36 mg·kg-1·d-1 for TAAs is underestimated. When compared with results previously determined in nonpregnant adults, early pregnancy requirements were similar (43 compared with 44 mg·kg-1·d-1, respectively). During late pregnancy, a 14% higher TAA requirement was observed when compared with early pregnancy. The results from this study have potential implications for creating gestation stage-specific TAA recommendations.
Sections du résumé
BACKGROUND
Phenylalanine and tyrosine (referred to as total aromatic amino acids; TAAs) are essential for protein synthesis, and are precursors for important catecholamines. Current estimated average requirement (EAR) recommendations for TAA during pregnancy are 36 mg·kg-1·d-1, and has not been experimentally determined.
OBJECTIVES
The aim was to determine TAA requirements (dietary phenylalanine in the absence of tyrosine) during early and late gestation using the indicator amino acid oxidation (IAAO, with L-[1-13C]leucine) technique.
METHODS
Nineteen healthy pregnant women (age 22-38 y) were studied at a range of phenylalanine intakes (5 to 100 mg·kg-1·d-1) in early (13-19 wk) and/or late (33-39 wk) pregnancy for a total of 51 study days. Graded test intakes were provided as 8 hourly isonitrogenous and isocaloric meals. Breath samples were collected for 13C enrichment analysis on an isotope ratio mass spectrometer. A plasma sample was collected and analyzed for phenylalanine and tyrosine concentrations on an amino acid analyzer. The TAA requirement in early and late pregnancy was calculated using 2-phase linear regression crossover analysis that identified breakpoints in 13CO2 production (the requirement) in response to phenylalanine intakes.
RESULTS
TAA requirement during early pregnancy was 44 mg·kg-1·d-1 (95% CI: 28.3, 58.8) and during late pregnancy was 50 mg·kg-1·d-1 (95% CI: 36.1, 63.1). In early and late pregnancy, plasma phenylalanine and tyrosine concentrations rose linearly in response to graded phenylalanine intakes.
CONCLUSIONS
Our results suggest that the current EAR of 36 mg·kg-1·d-1 for TAAs is underestimated. When compared with results previously determined in nonpregnant adults, early pregnancy requirements were similar (43 compared with 44 mg·kg-1·d-1, respectively). During late pregnancy, a 14% higher TAA requirement was observed when compared with early pregnancy. The results from this study have potential implications for creating gestation stage-specific TAA recommendations.
Identifiants
pubmed: 33188409
pii: S0022-3166(22)02415-4
doi: 10.1093/jn/nxaa317
pmc: PMC7726121
doi:
Substances chimiques
Amino Acids, Aromatic
0
Carbon Isotopes
0
Tyrosine
42HK56048U
Phenylalanine
47E5O17Y3R
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
3224-3230Subventions
Organisme : CIHR
ID : FRN 10321
Pays : Canada
Informations de copyright
© The Author(s) 2020. Published by Oxford University Press on behalf of the American Society for Nutrition.
Références
Am J Clin Nutr. 2020 Feb 1;111(2):351-359
pubmed: 31758682
Poult Sci. 2002 Apr;81(4):481-4
pubmed: 11989747
Am J Physiol. 1989 Sep;257(3 Pt 1):E426-38
pubmed: 2551178
Am J Clin Nutr. 2001 Feb;73(2):276-82
pubmed: 11157324
Hum Nutr Clin Nutr. 1985 May;39(3):167-79
pubmed: 3874856
J Clin Biochem Nutr. 2011 Sep;49(2):115-20
pubmed: 21980227
Eur J Clin Nutr. 1992 Jun;46(6):411-7
pubmed: 1639049
Nutr Res. 2014 Jul;34(7):569-76
pubmed: 25150115
Adv Nutr. 2016 Jul 15;7(4):839S-44S
pubmed: 27422521
Am J Clin Nutr. 2000 May;71(5 Suppl):1249S-55S
pubmed: 10799398
Am J Clin Nutr. 2006 Jun;83(6):1331-6
pubmed: 16762944
J Nutr. 2007 Jun;137(6 Suppl 1):1576S-1578S; discussion 1597S-1598S
pubmed: 17513429
Am J Physiol. 1990 Dec;259(6 Pt 1):E835-43
pubmed: 2260651
Br J Nutr. 1974 Jul;32(1):77-97
pubmed: 4843734
J Nutr. 2006 Jan;136(1 Suppl):281S-7S
pubmed: 16365099
J Anim Sci. 2006 Apr;84 Suppl:E155-65
pubmed: 16582088
Am J Clin Nutr. 2000 May;71(5 Suppl):1218S-25S
pubmed: 10799394
Am J Clin Nutr. 2007 Aug;86(2):360-5
pubmed: 17684206
IUBMB Life. 2013 Apr;65(4):341-9
pubmed: 23457044
Am J Clin Nutr. 1998 Apr;67(4):640-59
pubmed: 9537611
J Am Diet Assoc. 2002 Nov;102(11):1621-30
pubmed: 12449285
Am J Physiol Endocrinol Metab. 2004 Sep;287(3):E489-96
pubmed: 15308475
Amino Acids. 2016 Jul;48(7):1707-16
pubmed: 27138628
Br J Nutr. 2012 Aug;108 Suppl 2:S22-30
pubmed: 23107531
Am J Clin Nutr. 2006 Jan;83(1):82-8
pubmed: 16400054
J Nutr. 2006 Apr;136(4):958-64
pubmed: 16549457
J Nutr. 2015 Jan;145(1):73-8
pubmed: 25527661
Am J Clin Nutr. 2002 Oct;76(4):852-7
pubmed: 12324300
Am J Clin Nutr. 2008 Jul;88(1):115-24
pubmed: 18614731
J Nutr. 2018 Jan 1;148(1):94-99
pubmed: 29378056