Diurnal variations in blood phenylalanine of PKU infants under different feeding regimes.

Unlabelled: In phenylketonuria (PKU) patients, diurnal fluctuations of blood phenylalanine (Phe) are different from healthy individuals. Until now this pattern has been studied in PKU patients over one year of age.

Objective: The aim of this observational study was to investigate diurnal patterns in PKU infants under one year of age receiving both the natural protein and Phe-free formula at the same time or in an alternating feeding scheme.

Adult patients with well-controlled phenylketonuria tolerate incidental additional intake of phenylalanine.

Background/aims: In patients with phenylketonuria (PKU), target ranges of blood phenylalanine (Phe) concentrations have been tightened in order to improve long-term outcomes. We investigated day-to-day and week-to-week variations in blood Phe concentration and the effect of an additional Phe load.

Methods: We performed a longitudinal study in 6 adult PKU patients.