Quality of Life (QoL) assessment in a cohort of patients with phenylketonuria.

Aurora Daniele,Pamela Massa,Alessandro P Burlina,Laura Giordano,Alberto B Burlina,Luca Cegolon,Francesco Salvatore,Andrea Celato,Giulia Polo,Chiara Cazzorla

doi:10.1186/1471-2458-14-1243

Abstract

BackgroundPhenylketonuria (PKU) is a chronic inborn error of amino acid metabolism that requires lifelong follow-up and intervention, which may represent strains on Quality of Life (QoL). This observational study evaluated QoL in a cohort of PKU patients, using updated and detailed instruments.Methods22 patients with mild PKU respondent to BH4 and 21 patients with classical PKU treated with diet were recruited in this study. Adult patients completed WHOQOL questionnaire-100 (WHOQOL-100) and pediatric patients the Pediatric QoL inventory (PedsQLTM). Psychiatric and mood disorders were also evaluated using TAD or BDI and STAI-Y inventories. A multivariable linear regression model was fitted to investigate the predictors of QoL, including age, sex, treatment type, length of current treatment, educational level and employment status (only for adults) as covariates. Results were presented as regression coefficients with 95% confidence interval.ResultsGlobal QoL scores were within normal range both in patients with mild and classical disease but global QoL scores were significantly higher in patients with mild PKU under BH4 treatment as compared to those affected by classical disease who were under diet regimen. Furthermore, QoL significantly increased in long treated PKU patients. Among adult patients, QoL scores were significantly lower in males, in patients with lower education and in those employed or unemployed as compared to students (baseline).ConclusionsBoth diet and medical treatment based upon BH4 seem to be associated with higher QoL in the long run. However, patients with mild PKU can rely on BH4 to achieve a higher Phe tolerance and a better compliance to therapy due to diet relaxation/avoidance. Some specific categories of patients with a lower QoL should be investigated more in depth, engaging with those at risk of lower treatment compliance. The questionnaires employed in the present study seemed to be able to effectively detect criticalities in QoL assessment and represent an advance from previous inventories employed in the past.

Highlights

Phenylketonuria (PKU) is a chronic inborn error of amino acid metabolism that requires lifelong follow-up and intervention, which may represent strains on Quality of Life (QoL)
22 BH4 responsive patients affected by mild PKU and 21 classical PKU patients treated with diet were recruited in this study
– 21 classical PKU patients treated with diet alone; – 6 adult patients treated with sapropterin alone; – 8 patients treated with sapropterin as well as low protein foods and natural proteins; – 8 patients (7 children and 1 adult) requiring a combined treatment of sapropterin along with Phe restricted diet and a supplementation of Phe-free amino acid compounds

Summary

Introduction

Phenylketonuria (PKU) is a chronic inborn error of amino acid metabolism that requires lifelong follow-up and intervention, which may represent strains on Quality of Life (QoL). This observational study evaluated QoL in a cohort of PKU patients, using updated and detailed instruments. PAH deficiency leads to an accumulation of phenylalanine (Phe) in blood and brain that gradually impairs metabolic functioning and cognitive development [1]. PAH is mainly active in the liver and adults, the strict adherence to diet may lead to some difficulties in building up good social relationships [8], often resulting in poor adherence to dietary regimen with risks of cognitive, neuropsychological and behavioural impairment [9,10]. Current guidelines suggest that a trial with sapropterin can be provided to all PKU patients [13], patients with milder forms of the disease are more likely to benefit from BH4 treatment than classical ones

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