RESUMEN
BACKGROUND: Phenylketonuria (PKU) is an inherited error of metabolism, screened at 48-72 h of life since 1975 in Hungary. The patients have to keep a strict lifelong protein-restricted diet, resulting in PKU and its treatment can lead to social and financial burdens. The current study aimed to evaluate the health-related quality of life (HRQoL) of children living with PKU. PATIENTS AND METHODS: A single-centre, cross-sectional, observational study was conducted at the Center of Newborn Screening and Inherited Metabolic Disorders of Budapest, Hungary, using the PKU-quality of life (PKU-QoL) questionnaire. Responses of 59 parents and 11 teenagers were collected. Numerous aspects regarding HRQoL were analysed according to clinical compliance and severity. The patients were classified into groups with good or suboptimal adherence based on regular phenylalanine (Phe) values. The online officially translated versions of the adolescent or parental PKU-QoL questionnaire were used and analysed anonymously. Differences in HRQoL were compared - PKU vs. Hyperphenylalaninaemia (HPA) and good vs. suboptimal adherence. RESULTS: Twenty-five of 32 examined parameters had no or little impact on HRQoL. The most frequently reported symptom was irritability. Food enjoyment was the most impacted domain, with a major severity score in the adolescent group (median 62,5, IQR: 25-75). The emotional impact was scored at moderate severity by both the adolescents and parents. Classical PKU patients with good metabolic control were more frequently tired than HPA patients (0,0027). The group with poor metabolic adherence showed more frequent tiredness (p = 0,03), slow thinking (p = 0,018) and anxiety (p = 0,015). CONCLUSION: Overall, our patients showed an excellent HRQoL; most domains (29/36) were reported as little/no impacted. Worse QoL was found in patients with suboptimal metabolic control. Particular attention should be paid to the emotional health of PKU patients.
RESUMEN
BACKGROUND: The implementation of neonatal screening and the early initiation of lifelong therapy have helped to prevent severe complications and enabled much more favorable outcomes for early-treated phenylketonuria (ETPKU) patients. However, PKU patients tend to develop subtle cognitive and psychosocial abnormalities and the strict dietary therapy can present financial and social burden. Thus, PKU is expected to affect the quality of life (QoL) of these patients. There is insufficient evidence regarding the relationship between metabolic control and Health-Related QoL (HRQoL). We aimed to assess the effect of short- and long-term therapy on QoL among Hungarian adult PKU patients using the standardized PKU-specific PKU-QoL questionnaire. Methods: We conducted a single-centre, cross-sectional, observational study in Hungary. We included adult PKU patients treated with diet and amino acid supplements only. Patients reported HRQoL using the standardized adult PKU-QoL questionnaire and mean blood Phe concentrations were assessed for three different time periods: the previous 10 years, the previous year and concentration at the time of completing the questionnaire. The correlation between patients' QoL scores and their Phe levels was assessed. The classical PKU group was further divided into "good" and "suboptimal" adherence groups based on individual mean Phe levels in the examined time period. We evaluated differences in QoL among the two subgroups of classical PKU patients. QoL scores between classical and non-classical patients were also compared. Results: Data from 88 adult patients were analysed (66 had classical PKU). No median PKU-QoL score reached major or severe impact/frequent symptoms in any domain. The highest scores (meaning larger burden) were mostly related to emotional impact of PKU and disease management. When performing correlation analysis between Phe levels and QoL scores by all patients we found weak to fair positive correlation in several domains either short or long term. Patients with classical PKU reported greater financial impact of PKU than patients with less severe PKU. Classical PKU patients with good therapy adherence tended to report better HRQoL scores than patients with suboptimal adherence. Conclusion: We conclude that patients showed good HRQoL using the PKU-specific questionnaire. Our study demonstrates that suboptimal metabolic control is negatively associated with patients' HRQoL.
RESUMEN
Blood phenylalanine (Phe) values from the dried blood spots of all Estonian phenylketonuria (PKU) patients have been deposited into a unified electronic laboratory database for eight years, providing an opportunity to assess the adherence of the patients to dietary recommendations over time and to observe patient practices both individually and collectively. Our results demonstrate generally good adherence to clinical and dietary recommendations during the first six years of life, as the percentage of patients with median Phe values fitting under the national recommendation levels were 95%, 84% and 70% in age groups 0-1, 1-2 and 2-6â¯years, respectively. Conversely, significant deviations occur in the group of 6 to 12â¯year-olds, mildly decreasing in adolescence and increasing in adulthood (43%, 53% and 57%, respectively). Wide individual differences occurred in all groups, especially in patients with a classical PKU phenotype caused by PAH variants that fully abolish phenylalanine hydroxylase activity. Surprisingly, some of the best dietary adherence was seen in the late-diagnosed PKU patients with poor cognitive functioning. As a rule, the median of Phe values crosses the recommended thresholds in approximately one third to one half of the patients of each age group after the first two years of life.