Selenium status in infants and children with phenylketonuria and in maternal phenylketonuria

It is well established that the involvement of reactive species in the pathophysiology of several neurological diseases, including phenylketonuria (PKU), a metabolic genetic disorder biochemically characterized by elevated levels of phenylalanine (Phe). In previous studies, we verified that PKU patients (treated with a protein-restricted diet supplemented with a special formula not containing L-carnitine and selenium) presented high lipid and protein oxidative damage as well as a reduction of antioxidants when compared to the healthy individuals. Our goal in the present study was to evaluate the effect of Phe-restricted diet supplemented with L-carnitine and selenium, two well-known antioxidant compounds, on oxidative damage in PKU patients. We investigated various oxidative stress parameters in blood of 18 treated PKU patients before and after 6 months of supplementation with a special formula containing L-carnitine and selenium. It was verified that treatment with L-carnitine and selenium was capable of reverting the lipid peroxidation, measured by thiobarbituric acid-reactive species, and the protein oxidative damage, measured by sulfhydryl oxidation, to the levels of controls. Additionally, the reduced activity of glutathione peroxidase was normalized by the antioxidant supplementation. It was also verified a significant inverse correlation between lipid peroxidation and L-carnitine blood levels as well as a significant positive correlation between glutathione peroxidase activity and blood selenium concentration. In conclusion, our results suggest that supplementation of L-carnitine and selenium is important for PKU patients since it could help to correct the oxidative stress process which possibly contributes, at least in part, to the neurological symptoms found in phenylketonuric patients.

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“…Furthermore, selenium has a higher affinity for erythrocyte glutathione peroxidase than for plasma glutathione peroxidase (Lombeck et al 1996).…”

Section: Discussionmentioning

confidence: 99%

Evidence that l-Carnitine and Selenium Supplementation Reduces Oxidative Stress in Phenylketonuric Patients

et al. 2010

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“…Furthermore, selenium supplementation with recovery of glutathione peroxidase activity resulted in improvement of oxidative stress markers in PKU patients [45], [46]. Strong restriction of protein intake in pregnant PKU patients to maintain low phenylalanine blood level could lead to severe hyposelenemia [39]. To our knowledge, there are no reports of PKU patients with selenium deficiency in Japan.…”

Section: Discussionmentioning

confidence: 93%

“…Selenium insufficiency has not been reported in Japanese on normal diet. However, low blood selenium levels have been reported in PKU patients and selenium deficiency has been reported in patients on long-term intravenous nutrition and enteral feeding [32], [33], [34], [35], [36], [37], [38], [39]. In Japan, Phe-free milk, A-1 and MP-11 contain small amounts of selenium; 1 μg, 2 μg, 11 μg/100 g, respectively.…”

Section: Discussionmentioning

confidence: 99%

Nutritional status of patients with phenylketonuria in Japan

Okano

Hattori

Fujimoto

et al. 2016

Molecular Genetics and Metabolism Reports

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Accumulating evidence suggests that hyperphenylalaninemia in phenylketonuria (PKU) can cause neuropsychological and psychosocial problems in diet-off adult patients, and that such symptoms improve after resumption of phenylalanine-restricted diet, indicating the need for lifetime low-phenylalanine diet. While limiting protein intake, dietary therapy should provide adequate daily intake of energy, carbohydrates, fat, vitamins, and microelements. We evaluated nutrient balance in 14 patients with classical PKU aged 4–38 years. Approximately 80–85% of the recommended dietary allowance (RDA) of protein in Japanese was supplied through phenylalanine-free (Phe-free) milk and Phe-free amino acid substitutes. Nutritional evaluation showed that the calorie and protein intakes were equivalent to the RDA. Phenylalanine intake was 9.8 ± 2.2 mg/kg of body weight/day, which maintained normal blood phenylalanine concentration by the 80% Phe-free protein rule. The protein, fat, and carbohydrate ratio was 9.5:23.9:66.6% with relative carbohydrate excess. Phe-free milk and amino acid substitutes provided 33.7% of carbohydrate, 82.1% of protein, and 66.7% of fat intake in all. Selenium and biotin intakes were 25.0% and 18.1% of the RDA and adequate intake (AI) for Japanese, respectively; both were not included in Phe-free milk. PKU patients showed low serum selenium, low urinary biotin, and high urinary 3-hydroxyisovaleric acid in this study. The intakes of magnesium, zinc, and iodine were low (71.5%, 79.5%, and 71.0% of the RDA, respectively) and that of phosphorus was 79.7% of the AI, although they were supplemented in Phe-free milk. PKU patients depend on Phe-free milk and substitutes for daily requirement of microelements and vitamins as well as protein and fat. Development of low-protein food makes it possible to achieve the aimed phenylalanine blood level, but this lowers the intake of microelements and vitamins from natural foods. The dietary habits vary continuously with age and environment in PKU patients. We recommend the addition of selenium and biotin to Phe-free milk in Japan and the need to review the composition of microelements and vitamins in A-1 and MP-11 preparations.

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“…Embora se tenha verificado aumento significativo das concentrações de selênio e GPX nos eritrócitos, bem como diminuição significativa de T4L, as concentrações séricas de selênio não Tabela 2 -Médias de selênio em microgramas por dia (mcg/dia) oferecidas pelos alimentos e pela mistura de aminoácidos, de acordo com as faixas etárias estudadas Este é o único estudo brasileiro que analisa o hormônio tireoidiano (T4L) sob o ponto de vista da deficiência de selênio, além de ser o único trabalho brasileiro relatando a complementação de selênio em crianças em tratamento para PKU. Concentrações de T4L acima dos valores de referência foram encontradas em alguns dos pacientes, o que pode ser explicado por um decréscimo na atividade da enzima 5' iodotironina deiodinase, em consequência de concentrações reduzidas de selênio no organismo [17][18][19] . Após a complementação com o mineral, as concentrações de T4L desses pacientes, bem como as de todo o grupo, reduziram-se significativamente, mantendo-se nos limites adequados, o que pode ser explicado pela maior disponibilidade de selênio, em decorrência da normalização da ingestão, semelhante ao que foi verificado em outros estudos 7,19 .…”

Section: Discussionunclassified

Selenium intake and nutritional status of children with phenylketonuria in Minas Gerais, Brazil

Alves¹,

Starling²,

Kanufre³

et al. 2012

J Pediatr (Rio J)

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Objective: To evaluate selenium dietary intake and nutritional status of patients with phenylketonuria. Methods:The study prospectively evaluated 54 children with phenylketonuria, from 4 to10 years old. The study was performed before and after the use of a selenium-supplemented amino acid mixture. The second phase of the study was performed after, at least, 90 days of use of the supplementation. Selenium nutritional status was assessed through the analysis of biochemical parameters: serum free thyroxin and selenium and glutathione peroxidase in erythrocytes. Selenium dietary intake was evaluated by the administration of the Food Frequency Questionnaire.Results: Mean age of the children was of 7.0±1.8 years, and 35.2% were female. Mean time of supplementation of selenium, on special formula, was 122.2±25.1 days. The selenium-supplemented amino acid mixture represented 72.9% of the daily supply of the mineral. Upon supplementation, mean concentrations of serum selenium and glutathione peroxidase in erythrocytes increased significantly (p < 0.05). The average daily intake of selenium increased significantly (p < 0.001), reaching the levels recommended by the Dietary Reference Intakes. The concentration of free thyroxin, in serum, presented significant reduction (p < 0.001) in all patients during the second phase of the study, and returned to normal limits in those who had changed levels. Conclusion:Selenium supplementation through protein replacement is effective to improve and adapt the nutritional status of selenium in patients with phenylketonuria.J Pediatr (Rio J). 2012;88(5):396-400: Phenylketonuria, selenium, glutathione peroxidase, thyroid hormones. ResumoObjetivo: Avaliar a ingestão alimentar e o estado nutricional em selênio em pacientes com fenilcetonúria. Métodos:Foram avaliados prospectivamente 54 crianças com fenilcetonúria, entre 4 e 10 anos de idade. O estudo foi realizado antes e após o uso de mistura de aminoácidos complementada com selênio. A segunda fase do estudo foi realizada com, no mínimo, 90 dias de utilização da mistura complementada. O estado nutricional em selênio foi avaliado por meio da análise de parâmetros bioquímicos: dosagens séricas de selênio e tiroxina livre e dosagem de glutationa peroxidase no eritrócito. A ingestão alimentar de selênio foi avaliada por aplicação de Questionário de Frequência Alimentar Quantitativo.Resultados: A idade média das crianças foi de 7,0±1,8 anos, e 35,2% eram do sexo feminino. O tempo médio de complementação de selênio, em fórmula especial, foi de 122,2±25,1 dias. A mistura de aminoácidos complementada com o mineral representou 72,9% da oferta diária de selênio. Após a complementação, as concentrações médias de selênio sérico e de glutationa peroxidase no eritrócito apresentaram aumento significativo (p < 0,05). A ingestão média diária de selênio aumentou significativamente (p < 0,001), alcançando o recomendado pela Ingestão Dietética de Referência. A concentração de tiroxina livre, no soro, apresentou redução significativa (p < 0,001) em tod...

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Selenium status in infants and children with phenylketonuria and in maternal phenylketonuria

Cited by 25 publications

References 27 publications

Evidence that l-Carnitine and Selenium Supplementation Reduces Oxidative Stress in Phenylketonuric Patients

Evidence that l-Carnitine and Selenium Supplementation Reduces Oxidative Stress in Phenylketonuric Patients

Nutritional status of patients with phenylketonuria in Japan

Selenium intake and nutritional status of children with phenylketonuria in Minas Gerais, Brazil

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