Lipophilic antioxidants in patients with phenylketonuria

• Published in: The American journal of clinical nutrition Vol. 77; no. 1; pp. 185 - 188
• Main Authors: COLOME, Catrina, ARTUCH, Rafael, VILASECA, Maria-Antortia, SIERRA, Cristina, BRANDI, Nuria, LAMBRUSCHINI, Nilo, CAMBRA, Francisco J, CAMPISTOL, Jaume
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Clinical Nutrition 2003; American Society for Clinical Nutrition, Inc
• Subjects: Adolescent; Adult; Aminoacid disorders; Antioxidants; Antioxidants - metabolism; Biological and medical sciences; Case-Control Studies; Child; Child, Preschool; Cross-Sectional Studies; Errors of metabolism; Female; Humans; Lipid Peroxidation; Lipids; Male; Medical sciences; Metabolic diseases; Oxidative Stress; Patients; Phenylketonurias - blood; Phenylketonurias - diet therapy; Plasma; Tocopherols - blood; Ubiquinone - blood; Glutathione peroxidase; Human; Nervous system diseases; Phenylketonuria; Pathophysiology; Enzyme; Biological marker; Metabolic diseases; Lipids; Antioxidant; Enzymopathy; Feeding; Genetic disease; Lipophilic compound; Ubiquinone; Peroxidases; Enzymatic activity; Diet; Oxidoreductases; Aminoacid disorder; Peroxidation
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/77.1.185

Low serum ubiquinone-10 concentrations have been described in phenylketonuric patients fed natural-protein-restricted diets. Such low concentrations may be related to increased free radical damage. We evaluated the relation between low serum ubiquinone-10 concentrations and other lipophilic antioxidants (tocopherol and retinol), selenium, glutathione peroxidase activity, and malondialdehyde concentrations as a marker of lipid peroxidation. This was a cross-sectional study of 58 patients with phenylketonuria (aged 2-36 y; median: 13 y) under dietary treatment, 58 age-matched control subjects, and 30 children with moderate hyperphenylalaninemia fed unrestricted diets (aged 3-17 y; median: 7.5 y). Serum ubiquinone-10 concentrations were analyzed by HPLC with electrochemical detection. Serum retinol, serum tocopherol, and plasma malondialdehyde were analyzed by HPLC with ultraviolet detection. A significant positive correlation was observed between ubiquinone-10 and tocopherol (r = 0.510, P < 0.001) in the patients with phenylketonuria. After the patients were stratified into 2 groups according to ubiquinone-10 values, significantly lower concentrations of tocopherol were observed in group 1 (low ubiquinone values) than in group 2 (normal ubiquinone values), the hyperphenylalaninemic children, and the control group. Plasma malondialdehyde concentrations were significantly higher in group 1 than in the other groups. No significant differences between groups 1 and 2 were observed in daily intakes of selenium, ascorbate, tocopherol, or retinol. Plasma lipid peroxidation seems to be increased in phenylketonuria. Low concentrations of ubiquinone-10 could be associated with either excessive tocopherol consumption or high malondialdehyde concentrations in patients with phenylketonuria.