Is there any health risk of low dietary selenium supply in PKU-children?

Abstract

87 participants of the German collaboratory study for children with phenylketonuria (PKU) were investigated in order to monitor effects of a low selenium (Se) supply. The low selenium intake results from the semisynthetic “PKU-diet” which is not supplemented with selenium. The influence of the low selenium state on different clinical and biochemical parameters was evaluated. Samples of 34 healthy children of matching age and sex (on a normal diet) were analysed to achieve contemporary reference values. All PKU children presented a low selenium state (low plasma, whole blood, and hair Se values, reduced urinary selenium excretion, and decreased plasma and erythrocyte glutathione peroxidase activity (GSH-Px A)) in comparison with the healthy reference group (all figures p < 0,001). The investigated hematological and biochemical parameters were found to be within normal range (except T). The aspartate amino transferase (ASAT) was found to be negatively correlated with plasma Se (ASAT / plasma Se: p = 0,006). Plasma thyroxine (T 4) was higher in PKU children compared with the reference group. This hormone was inversely correlated with the selenium blood values of the PKU children. (T 4 /whole blood Se p = 0,001). The somatic measurements showed a negative standard deviation score (SDS) of the body height in the PKU children compared with reference values. Despite the difference in Se supply the infants did not present any specific Se deficiency symptoms.