title: Nutritional Changes and Micronutrient Supply in Patients with Phenylketonuria Under Therapy with Tetrahydrobiopterin (BH(4)).
abstract: BACKGROUND
  Since 2008 patients with BH(4)-sensitive phenylketonuria can be treated with sapropterin dihydrochloride (Kuvan®) in addition to the classic phenylalanine (Phe) restricted diet. The aim of this study was to evaluate the nutritional changes and micronutrient supply in patients with phenylketonuria (PKU) under therapy with tetrahydrobiopterin (BH(4)).
  
  
  METHODS
  19 children with PKU (4-18 years) and potential BH(4)-sensitivity were included, 14 completed the study protocol. Dried blood Phe concentrations as well as detailed dietary records were obtained throughout the study at preassigned study days.
  
  
  RESULTS
  Eight patients could increase their Phe tolerance from 629 ± 476 mg to 2131 ± 1084 mg (P = 0.006) under BH(4) while maintaining good metabolic control (Phe concentration in dried blood 283 ± 145 μM vs. 304 ± 136 μM, P = 1.0), therefore proving to be BH(4)-sensitive. They decreased their consumption of special low protein products and fruit while increasing their consumption of high protein foods such as processed meat, milk and dairy products. Intake of vitamin D (P = 0.016), iron (P = 0.002), calcium (P = 0.017), iodine (P = 0.005) and zinc (P = 0.046) significantly declined during BH(4) treatment while no differences in energy and macronutrient supply occurred.
  
  
  CONCLUSIONS
  BH(4)-sensitive patients showed good metabolic control under markedly increased Phe consumption. However, the insufficient supply of some micronutrients needs consideration. Long-term multicenter settings with higher sample sizes are necessary to investigate the changes of nutrient intake under BH(4) therapy to further evaluate potential risks of malnutrition. Supplementation may become necessary.
authors: Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: A G
authors: AG
authors: Thiele
authors: Department of Women and Child Health, Hospital for Children and Adolescents, Centre of Paediatric Research (CPR), University Hospitals, University of Leipzig, Liebigstraße 20 a, D-04103, Leipzig, Germany.
authors: J F
authors: JF
authors: Weigel
authors: Department of Women and Child Health, Hospital for Children and Adolescents, Centre of Paediatric Research (CPR), University Hospitals, University of Leipzig, Liebigstraße 20 a, D-04103, Leipzig, Germany.
authors: B
authors: B
authors: Ziesch
authors: Department of Women and Child Health, Hospital for Children and Adolescents, Centre of Paediatric Research (CPR), University Hospitals, University of Leipzig, Liebigstraße 20 a, D-04103, Leipzig, Germany.
authors: C
authors: C
authors: Rohde
authors: Department of Women and Child Health, Hospital for Children and Adolescents, Centre of Paediatric Research (CPR), University Hospitals, University of Leipzig, Liebigstraße 20 a, D-04103, Leipzig, Germany.
authors: U
authors: U
authors: Mütze
authors: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany.
authors: U
authors: U
authors: Ceglarek
authors: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Leipzig, Germany.
authors: J
authors: J
authors: Thiery
authors: Institute of Agricultural and Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany.
authors: A S
authors: AS
authors: Müller
authors: Department of Women and Child Health, Hospital for Children and Adolescents, Centre of Paediatric Research (CPR), University Hospitals, University of Leipzig, Liebigstraße 20 a, D-04103, Leipzig, Germany.
authors: W
authors: W
authors: Kiess
authors: Department of Women and Child Health, Hospital for Children and Adolescents, Centre of Paediatric Research (CPR), University Hospitals, University of Leipzig, Liebigstraße 20 a, D-04103, Leipzig, Germany. Skadi.Beblo@medizin.uni-leipzig.de.
authors: S
authors: S
authors: Beblo