The beneficial effect of adherence to the therapeutic diet on the main protein-energy wasting and several other biomarkers in children with phenylketonuria

Abstract

Replacement of natural protein intake, low total antioxidant status (TAS) and DNA oxidation and high phenylalanine (Phe) blood levels are implicated with poorly controlled patients with PKU. In this study we aimed to investigate the effect of diet on the main Protein Energy Wasting (PEW) along with other metabolic parameters in patients with phenylketonuria (PKU). Twenty-four poorly controlled patients (group A) and thirty patients who strictly adhered to their diet (group B) as well as controls (n = 50) underwent laboratory tests: complete blood count, concentrations of ferritin, lipid, lipoprotein, TAS, as well as Phe levels with appropriate methodology. Phe levels differed significantly among the groups. Lipids lipoproteins, except HDL, were higher in group A than those measured in group B and controls. TG was not higher in any group. TAS (386 ± 30 vs 204 ± 23 μmol/L, p < 0.001), ferritin (65 ± 12 vs 52 ± 10 μg/L, p < 0.01) were significantly higher in group B. In contrast, White Blood Cell count (WBC) (6.1 ± 1.0 vs 8.3 ± 1.2 × 10³/μL, p < 0.01), the absolute number (1.9 ± 0.6 vs 2.9 ± 0.7 × 10³/μL, p < 0.001) and percentage of lymphocytes (18.5 ± 3.0 vs 39.3 ± 4.0%, p < 0.01) were lower in group A than those in group B, whereas total protein and albumin levels were similar among the groups. Most main PEW biomarkers, the low WBC, the low absolute and percentage of lymphocytes in poorly controlled patients may be directly and/or indirectly affected by their high Phe levels and/or low TAS levels in children with PKU on “loose diet”.

Keywords

PKU - diet - biomarkers - phenylalanine - oxidation - PEW