ClinicalStudy Comparison of Glycomacropeptide with Phenylalanine Free-SyntheticAminoAcidsinTestMealstoPKUPatients: No Significant Differences in Biomarkers, Including Plasma Phe Levels KirstenK.Ahring , 1,2,3 AllanM.Lund, 2,3 ErikJensen, 4 ThomasG.Jensen, 5 Karen Brøndum-Nielsen, 1 Michael Pedersen, 6 AllanBardow, 7 JensJuulHolst , 8 JensF.Rehfeld, 9 andLisbethB.Møller 2 1 e PKU Clinic, Kennedy Centre, Centre for Paediatric and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, enmark 2 epartment of Clinical Genetics, Applied Human Molecular Genetics, Kennedy Center, Rigshospitalet, enmark 3 Centre for Inherited Metabolic iseases, Centre for Paediatric and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, enmark 4 Arla Foods Ingredients Group P/S, Viby J, enmark 5 epartment of Biomedicine, Aarhus University, Aarhus, enmark 6 epartment of Clinical Medicine, Aarhus University Hospital, Aarhus, enmark 7 epartment of Odontology, Copenhagen University, Copenhagen, enmark 8 Institute of Clinical Medicine, Copenhagen University Hospital, Rigshospitalet, Copenhagen, enmark 9 epartment of Clinical Biochemistry, University of Copenhagen, Rigshospitalet, Copenhagen, enmark Correspondence should be addressed to Kirsten K. Ahring; kka@kennedy.dk Received 14 July 2017; Accepted 11 October 2017; Published 8 January 2018 Academic Editor: Ina Knerr Copyright © 2018 Kirsten K. Ahring et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction. Management of phenylketonuria (PKU) is achieved through low-phenylalanine (Phe) diet, supplemented with low- protein food and mixture of free-synthetic (FS) amino acid (AA). Casein glycomacropeptide (CGMP) is a natural peptide released in whey during cheese-making and does not contain Phe. Lacprodan ® CGMP-20 used in this study contained a small amount of Phe due to minor presence of other proteins/peptides. Objective. e purpose of this study was to compare absorption of CGMP-20 to FSAA with the aim of evaluating short-term effects on plasma AAs as well as biomarkers related to food intake. Methods. is study included 8 patients, who had four visits and tested four drink mixtures (DM1–4), consisting of CGMP, FSAA, or a combination. Plasma blood samples were collected at baseline, 15, 30, 60, 120, and 240 minutes (min) after the meal. AA profiles and ghrelin were determined 6 times, while surrogate biomarkers were determined at baseline and 240 min. A visual analogue scale (VAS) was used for evaluation of taste and satiety. Results. e surrogate biomarker concentrations and VAS scores for satiety and taste were nonsignificant between the four DMs, and there were only few significant results for AA profiles (not Phe). Conclusion. CGMP and FSAA had the overall same nonsignificant short-term effect on biomarkers, including Phe. is combination of FSAA and CGMP is a suitable supplement for PKU patients. 1.Introduction Phenylketonuria (PKU) is an inborn error of metabolism. If left untreated, severe brain damage will occur [1–3]. e primary aim of treatment of those suffering from PKU is to control the blood phenylalanine (Phe) concentration in order to prevent neurological damage [2]. PKU treatment is based on a low-protein (LP) diet in combination with free- synthetic (FS) amino acid (AA) supplements without Phe and enriched with vitamins, minerals, trace elements, and in Hindawi Journal of Nutrition and Metabolism Volume 2018, Article ID 6352919, 11 pages https://doi.org/10.1155/2018/6352919