Advances in Clinical and Experimental Medicine

Title abbreviation: Adv Clin Exp Med
JCR Impact Factor (IF) – 2.1
5-Year Impact Factor – 2.2
Scopus CiteScore – 3.4 (CiteScore Tracker 3.6)
Index Copernicus  – 161.11; MNiSW – 70 pts

ISSN 1899–5276 (print)
ISSN 2451-2680 (online)
Periodicity – monthly

Download original text (EN)

Advances in Clinical and Experimental Medicine

2019, vol. 28, nr 10, October, p. 1385–1391

doi: 10.17219/acem/104536

Publication type: original article

Language: English

Download citation:

  • BIBTEX (JabRef, Mendeley)
  • RIS (Papers, Reference Manager, RefWorks, Zotero)

Therapy compliance in children with phenylketonuria younger than 5 years: A cohort study

Dariusz Walkowiak1,A,B,C,D,E,F, Anna Bukowska-Posadzy2,3,B,C,E,F, Łukasz Kałużny2,B,C,E,F, Mariusz Ołtarzewski4,B,C,E,F, Rafał Staszewski1,C,E,F, Michał Musielak5,A,E,F, Jarosław Walkowiak2,A,C,D,E,F

1 Department of Organization and Management in Health Care, Poznan University of Medical Sciences, Poland

2 Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, Poland

3 Department of Clinical Psychology, Poznan University of Medical Sciences, Poland

4 Department of Screening Tests, Institute of Mother and Child, Warszawa, Poland

5 Department of Social Sciences, Poznan University of Medical Sciences, Poland

Abstract

Background. Phenylketonuria (PKU) is a metabolic disease. It is manifested by a complete or partial inability to convert phenylalanine (Phe) to tyrosine and leads to increased concentrations of Phe in the blood and in other tissues, including the brain, causing irreversible neurological damage if left untreated. Low-phenylalanine diet is a key component of classical PKU therapy.
Objectives. The objective of this study was to assess the effectiveness of classical phenylketonuria therapy and compliance with doctors’ recommendations in the first 5 years of life.
Material and Methods. Data was collected from all diagnosed and treated patients (n = 57) born 1999–2010. Phenylalanine blood levels, the number of visits to a specialist outpatients’ center, the number of blood tests, as well as socioeconomic status (SES) and parents’ education level have been analyzed, and potential relationships have been assessed.
Results. In the 1st year of life patients visited their doctors (odds ratio (OR) = 6.8267; 95% confidence interval (95% CI) = 2.827–16.5163; p < 0.0001) and had their blood collected (OR = 2.7875; 95% CI = 1.0467–7.4234; p < 0.0402) significantly more frequently than in the 2nd year. This tendency persisted into subsequent years. Similarly, in infancy they had statistically significantly lower odds of exceeding more than 40% of their Phe levels over therapeutic range than 1 year later (OR = 3.6078; 95% CI = 1.4859–8.7599; p < 0.0046). No PKU child had more than 70% of Phe levels over the therapeutic range in the 1st year of life, whereas 4 years later there were 18 such children. Phe levels were correlated with the number of visits to a specialist (ρ = 0.39) and the number of Phe blood tests with index of dietary control (ρ = −0.33). The effectiveness of therapy and compliance with the doctor’s recommendations seem to depend neither on the level of education of the patient’s parents nor on their SES.
Conclusion. Therapy effectiveness and patients’ compliance in PKU is very good in infancy. However, both deteriorate in subsequent years. Moreover, they do not seem to depend on the family background.

Key words

compliance, diet, phenylketonuria, inborn errors of metabolism, phenylalanine

References (23)

  1. Blau N, Van Spronsen FJ, Levy HL. Phenylketonuria. Lancet. 2010;376(9750):1417–1427.
  2. Blainey JD, Gulliford R. Phenylalanine-restricted diets in the treatment of phenylketonuria. Arch Dis Child. 1956;31(160):452–466.
  3. MacDonald A, Gokmen-Ozel H, van Rijn M, Burgard P. The reality of dietary compliance in the management of phenylketonuria. J Inherit Metab Dis. 2010;33(6):665–670.
  4. Güttler F. Hyperphenylalaninemia: Diagnosis and classification of the various types of phenylalanine hydroxylase deficiency in childhood. Acta Paediatr Scand Suppl. 1980;280:1–80.
  5. Trefz FK, Schmidt H, Bartholome K, Mahle M, Mathis P, Pecht G. Differential diagnosis and significance of various hyperphenylalaninemias. In: Bickel H, Wachtel U, eds. Inherited Diseases of Amino Acid Metabolism. Stuttgart, West Germany: Georg Thieme Verlag KG; 1985:86–100.
  6. Phenylketonuria: Screening and Management. NIH Consensus Statement 2000 October 16–18;17:1–27.
  7. Management of PKU. A Consensus Document for the Diagnosis and Management of Children, Adolescents and Adults with Phenylketonuria. London, UK: The National Society for Phenylketonuria (UK) Ltd.; 2014.
  8. Burgard P, Bremer HJ, Bührdel P, et al. Rationale for the German recommendations for phenylalanine level control in phenylketonuria 1997. Eur J Pediatr. 1999;158(1):46–54.
  9. van Spronsen FJ, Ahring Kiær K, Gizewska M. PKU: What is daily practice in various centres in Europe? J Inherit Metab Dis. 2009;32(1):58–64.
  10. van Spronsen FJ, van Wegberg AM, Ahring K, et al. Key European guidelines for the diagnosis and management of patients with phenylketonuria. Lancet Diabetes Endocrinol. 2017;5(9):743–756. doi:10.1016/S2213-8587(16)30320-5
  11. Ahring K, Bélanger-Quintana A, Dokoupil K, et al. Blood phenylalanine control in phenylketonuria: A survey of 10 European centres. Eur J Clin Nutr. 2011;65(2):275–278.
  12. Walter JH, White FJ, Hall SK, et al. How practical are recommendations for dietary control in phenylketonuria? Lancet. 2002;60(9326):55–57.
  13. Waitzman N, Bilginsoy C, Leonard CO, Ernst SL, Prince A. The Effect of Phenylalanine Test Frequency on Management of Phenylketonuria (PKU). Working paper No: 2004-3. Salt Lake City, UT: University of Utah, Department of Economics; 2004.
  14. Recommendations on the dietary management of phenylketonuria. Report of Medical Research Council Working Party on Phenylketonuria. Arch Dis Child. 1993;68(3):426–427.
  15. Viau KS. Correlation of Age-Specific Phenylalanine Levels on Intellectual Outcome in Patients with Phenylketonuria [doctoral dissertation]. All Graduate Theses and Dissertations. Paper 739. Logan UT: Utah State University; 2010.
  16. Viau KS, Wengreen HJ, Ernst SL, Cantor NL, Furtado LV, Longo N. Correlation of age-specific phenylalanine levels with intellectual outcome in patients with phenylketonuria. J Inherit Metab Dis. 2011;34(4):963–971.
  17. Hartnett C, Salvarinova-Zivkovic R, Yap-Todos E, et al. Long-term outcomes of blood phenylalanine concentrations in children with classical phenylketonuria. Mol Genet Metab. 2013;108(4):255–258.
  18. Cotugno G, Nicolò R, Cappelletti S, Goffredo BM, Vici Dionisi C, Di Ciommo V. Adherence to diet and quality of life in patients with phenylketonuria. Acta Paediatr. 2011;100(8):1144–1149.
  19. Vieira TA, Nalin T, Krug BC, Bittar CM, Netto CBO, Schwartz IVD. Adherence to treatment of phenylketonuria: A study in southern Brazilian patients. J Inborn Errors Metab Screen. 2015;3:1–7.
  20. Acosta PB, Wenz E. Nutrition in Phenylketonuria. In: Bickel H, Hudson FP, Woolf LE, eds. Phenylketonuria and Some Other Inborn Errors of Amino Acid Metabolism. Stuttgart, West Germany: Georg Thieme Verlag KG; 1971:181–96.
  21. Cabalska MB, Nowaczewska I, Sendecka E, Zorska K. Longitudinal study on early diagnosis and treatment of phenylketonuria in Poland. Eur J Pediatr. 1996;155 (Suppl 1):S53–S55.
  22. Burgard P, Schmidt E, Rupp A, Schneider W, Bremer H. Intellectual development of the patients of the German Collaborative Study of children treated for phenylketonuria. Eur J Pediatr. 1996;55 (Suppl 1): S33–S38.
  23. Fisch RO, Matalon R, Weisberg S, Michals K. Phenylketonuria: Current dietary treatment practices in the United States and Canada. J Am Coll Nutr. 1997;16(2):147–151.