Glycomacropeptide: long-term use and impact on blood phenylalanine, growth and nutritional status in children with PKU.

ABSTRACT: In phenylketonuria, casein glycomacropeptide (CGMP) requires modification with the addition of some essential and semi essential amino acids to ensure suitability as a protein substitute. The optimal amount and ratio of additional amino acids is undefined. AIM:A longitudinal, parallel, controlled study over 12?months evaluating a CGMP (CGMP-AA2) formulation compared with phenylalanine-free L-amino acid supplements (L-AA) on blood Phe, Tyr, Phe:Tyr ratio, biochemical nutritional status and growth in children with PKU. The CGMP-AA2 contained 36?mg Phe per 20?g protein equivalent. METHODS:Children with PKU, with a median age of 9.2 y (5-16y) were divided into 2 groups: 29 were given CGMP-AA2, 19 remained on Phe-free L-AA. The CGMP-AA2 formula gradually replaced L-AA, providing blood Phe concentrations were maintained within target range. Median blood Phe, Tyr, Phe:Tyr ratio and anthropometry, were compared within and between the two groups at baseline, 26 and 52?weeks. Nutritional biochemistry was studied at baseline and 26?weeks only. RESULTS:At the end of 52?weeks only 48% of subjects were able to completely use CGMP-AA2 as their single source of protein substitute. At 52?weeks CGMP-AA2 provided a median of 75% (30-100) of the total protein substitute with the remainder being given as L-AA. Within the CGMP-AA2 group, blood Phe increased significantly between baseline and 52?weeks: [baseline to 26?weeks; baseline Phe 270??mol/L (170-430); 26?weeks, Phe 300??mol/L (125-485) p =?0.06; baseline to 52?weeks: baseline, Phe 270??mol/L (170-430), 52?weeks Phe 300??mol/L (200-490), p 

SUBMITTER: Daly A 

PROVIDER: S-EPMC6377744 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature