Longitudinal Dietary Intake Data in Patients with Phenylketonuria from Europe: The Impact of Age and Phenylketonuria Severity

• Published in: Nutrients Vol. 16; no. 17; p. 2909
• Main Authors: Pinto, Alex, Ahring, Kirsten, Almeida, Manuela Ferreira, Ashmore, Catherine, Bélanger-Quintana, Amaya, Burlina, Alberto, Coşkun, Turgay, Daly, Anne, van Dam, Esther, Dursun, Ali, Evans, Sharon, Feillet, François, Giżewska, Maria, Gökmen-Özel, Hulya, Hickson, Mary, Hoekstra, Yteke, Ilgaz, Fatma, Jackson, Richard, Leśniak, Alicja, Loro, Christian, Malicka, Katarzyna, Patalan, Michał, Rocha, Júlio César, Sivri, Serap, Rodenburg, Iris, van Spronsen, Francjan, Strączek, Kamilla, Tokatli, Ayşegül, MacDonald, Anita
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31-08-2024
• Subjects: Adolescent; Adult; Age Factors; Child; Child, Preschool; Dietary Proteins - administration & dosage; Enzymes; Europe - epidemiology; Female; Food; Humans; Infant; Longitudinal Studies; Male; Metabolism; Middle Aged; natural protein intake; Pediatrics; Phenylalanine - administration & dosage; Phenylalanine - blood; phenylalanine intake; Phenylketonuria; Phenylketonurias - blood; Phenylketonurias - diet therapy; Physiology; protein equivalent from protein substitute intake; Proteins; Retrospective Studies; Severity of Illness Index; Systematic review; total protein intake; Turkey - epidemiology; Young Adult; Europe; Turkey; United Kingdom > UK; protein equivalent from protein substitute intake; total protein intake; phenylketonuria; phenylalanine intake; natural protein intake
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu16172909

In phenylketonuria (PKU), natural protein intake is thought to increase with age, particularly during childhood and adolescence. Longitudinal dietary intake data are scarce and lifelong phenylalanine tolerance remains unknown. Nine centres managing PKU in Europe and Turkey participated in a retrospective study. Data were collected from dietetic records between 2012 and 2018 on phenylalanine (Phe), natural protein, and protein substitute intake. A total of 1323 patients (age range: 1-57 y; 51% male) participated. Dietary intake data were available on 1163 (88%) patients. Patient numbers ranged from 59 to 320 in each centre. A total of 625 (47%) had classical PKU (cPKU),
= 357 (27%) had mild PKU (mPKU),
= 325 (25%) had hyperphenylalaninemia (HPA), and
= 16 (1%) were unknown. The mean percentage of blood Phe levels within target ranged from 65 ± 54% to 88 ± 49%. When intake was expressed as g/day, the mean Phe/natural protein and protein equivalent from protein substitute gradually increased during childhood, reaching a peak in adolescence, and then remained consistent during adulthood. When intake was expressed per kg body weight (g/kg/day), there was a decline in Phe/natural protein, protein equivalent from protein substitute, and total protein with increasing age. Overall, the mean daily intake (kg/day) was as follows: Phe, 904 mg ± 761 (22 ± 23 mg/kg/day), natural protein 19 g ± 16 (0.5 g/kg/day ± 0.5), protein equivalent from protein substitute 39 g ± 22 (1.1 g/kg/day ± 0.6), and total protein 59 g ± 21 (1.7 g/kg/day ± 0.6). Natural protein tolerance was similar between males and females. Patients with mPKU tolerated around 50% less Phe/natural protein than HPA, but 50% more than cPKU. Higher intakes of natural protein were observed in Southern Europe, with a higher prevalence of HPA and mPKU compared with patients from Northern European centres. Natural protein intake doubled with sapropterin usage. In sapropterin-responsive patients, 31% no longer used protein substitutes. Close monitoring and optimisation of protein intake prescriptions are needed, along with future guidelines specifically for different age groups and severities.