Sustaining benefits of nutritional therapy in young adults with phenylketonuria - A 2 year prospective study

• Published in: Molecular genetics and metabolism reports 2020-03, Vol.22, p.100573-100573
• Main Author: Krämer, Johannes
• Format: Article
• Language: English
• Subjects: Research Paper
• ISSN: 2214-4269; 2214-4269
• DOI: 10.1016/j.ymgmr.2020.100573

Phenylketonuria (PKU) is an inborn error of metabolism, which is caused by a deficiency in the enzyme phenylalanine hydroxylase (PAH). Life-long Phe-free diet impairs quality of life, especially in adolescents and young adults which take responsibility over their diet and therapy from their parents, but expect freedom in daily routine. 105 patients with PKU were screened for eligibility for participating in this study. Data of 21 patients with genetic predictive value (GPV) ≤5 and age between 14 and 30 years were included in the analysis. Mean age of the study population was 22.6 ± 7.5 years, 8 patients (38%) were female. At baseline, structured counselling by a professional nutrionist was performed.Mean Phe-level at baseline was 926 ± 432 μmol/l, after six months Phe-levels were significantly reduced to 709 ± 314 μmol/l (  = .039), in total 4 additional patients (38% of the population) reached values within the therapeutic goal. After 12, 18 and 24 months, mean Phe-level elevated significantly to initial level (869 ± 427 μmol/l;  = .311). Mean daily intake of natural protein at baseline was 32.3 ± 24.3 g per day. There was a significant decrease after 6 months (26.9 ± 18.8 g/day;  = .049) and 12 months (25.9 ± 16.2 g/day;  = .30) compared to baseline. Values at 18 months (27.5 ± 9.2 g/day;  = .26) and 24 months (35.0 ± 22.3 g/day;  = .87) did not differ. Mean daily supplementation of Phe-free amino acids was 26.2 ± 19.2 g per day. In all follow-up examinations a significant increase compared to baseline values was calculated (42.4 ± 17.6 g/day after 6 moths (  = .028), 52.1 ± 29.9 g/day after 12 months (  ≤.01), 38.7 ± 20.3 g/day after 18 months (