Evaluation of the recommended dietotherapy efficiency for phenylketonuric patients by monitoring of blood phenylalanine levels.

Abstract

The hyperphenylalaninemias are metabolic disorders causing increased blood levels of the phenylalanine and may lead to abnormal development of patients if they are not adequately treated. In this study, it was evaluated treatment efficiency of dietary restriction recommended for phenylketonuric patients by monthly monitoring of blood phenylalanine levels. It was performed a cross-sectional population based study with twenty-one phenylketonuric patients undergoing dietotherapy. These patients were accomplished in the Central Laboratory of the state of Piauí. Blood phenylalanine levels were followed over a one year after initiation of the treatment. Of the studied patients, 52.4 % were male and 47.6 % were female. Phenylketonuria was diagnosed between 31-60 days and over the second month of birth in 60 % and 40 % of the patients, respectively. Based on blood phenylalanine levels, patients were classified into three groups: responders (33.3 %), non-responders (23.8 %) and anomalous responders (42.9 %). All responder patients were under four years old, and the majority in the anomalous group was aged over nine years, showing lower treatment adherence. The efficacy of treatment with diet therapy for reducing blood phenylalanine levels was mainly seen in younger patients (<4 years). It is believed that in the infant age the treatment tends to be more effective, possibly due to better monitoring of multidisciplinary care teams, besides the control accomplished by parents. Other individual patient studies are needed to better investigate and/or readapt the treatment for non-responders patients.