Practices in prescribing protein substitutes for PKU in Europe: No uniformity of approach

Background: There appears little consensus concerning protein requirements in phenylketonuria (PKU). Methods: A questionnaire completed by 63 European and Turkish IMD centres from 18 countries collected data on prescribed total protein intake (natural/intact protein and phenylalanine-free protein substitute [PS]) by age, administration frequency and method, monitoring, and type of protein substitute. Data were analysed by European region using descriptive statistics. Results: The amount of total protein (from PS and natural/intact protein) varied according to the European region. Higher median amounts of total protein were prescribed in infants and children in Northern Europe (n. =. 24 centres) (infants <. 1. year, >. 2-3. g/kg/day; 1-3. years of age, >. 2-3. g/kg/day; 4-10. years of age, >. 1.5-2.5. g/kg/day) and Southern Europe (n. =. 10 centres) (infants <. 1. year, 2.5. g/kg/day, 1-3. years of age, 2. g/kg/day; 4-10. years of age, 1.5-2. g/kg/day), than by Eastern Europe (n. =. 4 centres) (infants <. 1. year, 2.5. g/kg/day, 1-3. years of age, >. 2-2.5. g/kg/day; 4-10. years of age, >. 1.5-2. g/kg/day) and with Western Europe (n. =. 25 centres) giving the least (infants <. 1. year, >. 2-2.5. g/kg/day, 1-3. years of age, 1.5-2. g/kg/day; 4-10. years of age, 1-1.5. g/kg/day). Total protein prescription was similar in patients aged >. 10. years (1-1.5. g/kg/day) and maternal patients (1-1.5. g/kg/day). Conclusions: The amounts of total protein prescribed varied between European countries and appeared to be influenced by geographical region. In PKU, all gave higher than the recommended 2007 WHO/FAO/UNU safe levels of protein intake for the general population.