PHENYLKETONURIA AFFECTS THE SELENIUM STATUS OF CHILDREN, ADOLESCENTS,AND YOUNG-ADULTS

This cross-sectional study compared selenium status of 26 preschool (1 -5 yr), grade-school (6-11 yr), and older subjects (12-25 yr) on low p henylalanine diets for phenylketonuria (PKU), to that of 30 healthy, s imilarly aged controls. Plasma selenium was determined in PKU and cont rol subjects; plasma glutathione peroxidase activity (GPx) was assesse d in subjects with PKU. Mean selenium intakes for all age groups with PKU were below the selenium RDA and were significantly lower (P < 0.05 ) than that of similarly aged controls. Selenium intakes for grade-sch ool and older control groups were also below the selenium RDA. Mean pl asma selenium (ng/ml) for all subjects with PKU (98 +/- 6) was signifi cantly lower (P < 0.05) than that of all controls (125 +/- 6). Within age groups, plasma selenium was lower (P < 0.05) in preschoolers and g rade-schoolers with PKU than in similarly aged controls. Plasma seleni um concentrations for older controls were not different from those of older subjects with PKU but were lower (P < 0.01) than those of presch ool and grade-school controls. An increasing trend in GPx activity wit h age of subject was not significant. GPx of children with PKU appears to be maintained throughout childhood and adolescence. Results of thi s study indicate that plasma selenium in children with PKU is lower th an that of healthy children until 12-25 yr when plasma selenium concen trations of adolescents/young adults with or without PKU is similar. ( C) 1994 Wiley-Liss, Inc.