BH4 Tedavisi Alan Fenilketonüri Hastalarında Uzun Dönem Beslenme Durumunun Değerlendirilmesi

Abstract

Phenylketonuria (PKU) is an autosomal recessive disorder that leads to a defect in phenylalanine metabolism due to a deficiency of the enzyme phenylalanine hydroxylase (PAH). Hyperphenylalaninemia (HPA) can also occur when levels of tetrahydrobiopterin (BH4), a cofactor for the phenylalanine hydroxylase enzyme, are insufficient. Besides patients with cofactor deficiency, some PKU patients also respond to BH4. In patients who respond to the BH4 test, oral BH4 treatment is initiated, and dietary adjustments are made. For patients undergoing BH4 treatment, the diet can eventually return to normal over time. However, in long-term follow-up, various reasons can lead to an inability to consume protein sources in the recommended amounts, resulting in unmet nutritional needs. This study evaluated the nutritional status and certain anthropometric data of PKU patients who have been on BH4 treatment for more than 10 years at Hacettepe University İhsan Doğramacı Children's Hospital. At the end of the study, it was observed that 95% of patients could transition to a normal diet with BH4 treatment, and there was a statistically significant increase in dietary FA tolerance in patients (73.1%). It was found that the consumption of dairy products in the patients' current diet was significantly reduced compared to the end of the FA tolerance increase period and did not differ significantly from the beginning of BH4 treatment. Consequently, patients' calcium needs were not met, but total fat, saturated fat, and monounsaturated fat intakes were above the required levels (respectively 173.1±173.38, 161.2±76.45, 191.7±279.74). Patients' consumption of meat, grains, and bread increased throughout the treatment. There was a positive correlation between patients' height-for-age Z scores and total protein intake at the beginning of BH4 treatment (p<0.039). The rate of very short and short stature among patients decreased during BH4 treatment (from 31.7% to 27.1%), while the rate of overweight/obesity increased (from 28.3% to 45.4%). Energy and nutrient intake and anthropometric measurements of patients undergoing BH4 treatment should be monitored.