Overweight/obesity in adolescents with phenylketonuria: protective and predisposing factors

Abstract Objective: To estimate the prevalence and factors associated with overweight/obesity development in adolescents with early diagnosed phenylketonuria treated exclusively by diet. Methodology: In this cross-sectional study anthropometric measurements, serum phenylalanine levels, and 10 metabolites associated with lipid and carbohydrate metabolism were analyzed in 101 adolescents aged 10-20 years. Adolescents were categorized into overweight/obesity and eutrophic/low body mass index groups. These patients were compared using Student's t-test, Pearson's chi-square test, Wald's chi-square test for multivariate analysis. Further, to verify whether the prevalence of overweight/obesity found in the study population was similar to that in the general population, the authors compared the nutritional status of 46 patients aged 13-17 years with that of healthy students of the same age from the National School Health Survey using the chi-square test for adherence. The significance threshold was p < 0.5. Results: The prevalence of overweight/obesity in adolescents was 27.7%. There was no difference in prevalence between sexes. Older age was a protective factor and Increased Homeostasis Model Assessment Insulin Resistance index and high phenylalanine and low-density lipoprotein cholesterol levels were predictive factors for overweight/obesity. The equality hypothesis was not rejected in the comparison of nutritional states of 46 patients aged 13-17 years and healthy students of the same age. Conclusion: The prevalence of overweight/obesity in phenylketonuria adolescents was similar to what is found in healthy adolescents.

Overweight/obesity in adolescents with phenylketonuria: protective and predisposing factors.

OBJECTIVE: To estimate the prevalence and factors associated with overweight/obesity development in adolescents with early diagnosed phenylketonuria treated exclusively by diet. METHODOLOGY: In this cross-sectional study anthropometric measurements, serum phenylalanine levels, and 10 metabolites associated with lipid and carbohydrate metabolism were analyzed in 101 adolescents aged 10-20 years. Adolescents were categorized into overweight/obesity and eutrophic/low body mass index groups. These patients were compared using Student's t-test, Pearson's chi-square test, Wald's chi-square test for multivariate analysis. Further, to verify whether the prevalence of overweight/obesity found in the study population was similar to that in the general population, the authors compared the nutritional status of 46 patients aged 13-17 years with that of healthy students of the same age from the National School Health Survey using the chi-square test for adherence. The significance threshold was p < 0.5. RESULTS: The prevalence of overweight/obesity in adolescents was 27.7%. There was no difference in prevalence between sexes. Older age was a protective factor and Increased Homeostasis Model Assessment Insulin Resistance index and high phenylalanine and low-density lipoprotein cholesterol levels were predictive factors for overweight/obesity. The equality hypothesis was not rejected in the comparison of nutritional states of 46 patients aged 13-17 years and healthy students of the same age. CONCLUSION: The prevalence of overweight/obesity in phenylketonuria adolescents was similar to what is found in healthy adolescents.

Metabolic Control of Patients with Phenylketonuria in a Portuguese Metabolic Centre Comparing Three Different Recommendations.

Blood phenylalanine (Phe) is used as the primary marker to evaluate metabolic control. Our study aimed to describe the metabolic control of patients with phenylketonuria (PKU) comparing three different treatment recommendations (European guidelines/US guidelines/Portuguese consensus). This was a retrospective, observational, single centre study in patients with PKU collecting data on blood Phe levels from 2017. Nutritional intake data and sapropterin (BH4) prescription were collected at the last appointment of 2017. The final sample studied included 87 patients (48% females) [13 hyperphenylalaninemia; 47 mild PKU; 27 classical PKU] with a median age of 18 y (range: 1-36 y). The median number of blood Phe measurements for patients was 21 (range: 6-89). In patients aged < 12 y, the median blood Phe level was 300 µmol/L (range 168-480) and 474 µmol/L (range 156-1194) for patients ≥ 12 y. Overall, a median of 83% of blood Phe levels were within the European PKU guidelines target range. In patients aged ≥ 12 years, there was a higher median % of blood Phe levels within the European PKU guidelines target range (≥12 y: 84% vs. <12 y: 56%). In children < 12 y with classical PKU (n = 2), only 34% of blood Phe levels were within target range for all 3 guidelines and 49% with mild PKU (n = 11). Girls had better control than boys (89% vs. 66% median Phe levels within European Guidelines). Although it is clear that 50% or more patients were unable to achieve acceptable metabolic control on current treatment options, a globally agreed upper Phe target associated with optimal outcomes for age groups is necessary. More studies need to examine how clinics with dissimilar resources, different therapeutic Phe targets and frequency of monitoring relate to metabolic control.

Body fat percentage in adolescents with phenylketonuria and associated factors.

OBJECTIVE: To evaluate the percentage of body fat (% BF) in adolescents with PKU and to relate it to protein consumption, physical activity level, body mass index (BMI), sexual maturity and metabolic control. METHOD: This is a cross-sectional study conducted with 94 adolescents between 10 and 20 years of age, with early diagnosis and continuous treatment. Bioimpedance, weight measurements, height and BMI calculation were performed. Questionnaires were applied to quantify protein ingestion and establish the level of physical activity. Sexual maturity was assessed using the Tanner criteria. The annual mean of serum phenylalanine was used as a control parameter of the disease. A multivariate linear regression analysis was performed. RESULTS: Overweight, obesity, the female sex and the percentage of protein consumption explain 94.1% of the % BF of the patients (p < .05). The overweight prevalence was 19.1%. It was verified that 96.7% of the sample were sedentary. Only 50 (53.2%) of the adolescents had good treatment compliance, and no relationship was found between this variable and the % BF (p = .706). CONCLUSIONS: Being female and presenting high BMI values are important factors associated with % BF in phenylketonuric adolescents. Disease control and protein consumption do not seem to influence the body composition.

BH4 deficiency identified in a neonatal screening program for hyperphenylalaninemia / Deficiências de BH4identificadas em um programa de triagem neonatal para hiperfenilalaninemias

Abstract Objectives To show the general prevalence and to characterize tetrahydrobiopterin (BH4) deficiencies with hyperphenylalaninemia, identified by the Neonatal Screening Program of the State of Minas Gerais. Methods Descriptive study of patients with BH4 deficiency identified by the Neonatal Screening Program of the State of Minas Gerais. Results The prevalence found was 2.1 for 1,000,000 live births, with a frequency of 1.71% among hyperphenylalaninemias. There were four cases (40%) with 6-pyruvoyl-tetrahydropterin synthase deficiency, three with GTP cyclohydrolase I - autosomal recessive form deficiency, and three with dihydropteridine reductase deficiency (30% each). Six patients were diagnosed due to clinical suspicion and four cases due to systematic screening in neonatal screening. After the start of the treatment, patients identified by neonatal screening had rapid improvement and improved neuropsychomotor development compared to those diagnosed by the medical history. Conclusions The prevalence of BH4 deficiencies in Minas Gerais was slightly higher than that found in the literature, but the frequency among hyperphenylalaninemias was similar. Although rare, they are severe diseases and, if left untreated, lead to developmental delays, abnormal movements, seizures, and premature death. Early treatment onset (starting before 5 months of age) showed good results in preventing intellectual disability, justifying the screening of these deficiencies in newborns with hyperphenylalaninemia identified at the neonatal screening programs for phenylketonuria.

Resumo Objetivos Apresentar a prevalência geral e caracterizar as deficiências de tetrahidrobiopterina - BH4 - com hiperfenilalaninemia, identificadas pelo Programa de Triagem Neonatal do Estadode Minas Gerais. Métodos Estudo descritivo de pacientes com deficiência de BH4 do Programa de Triagem Neonatal do Estado de Minas Gerais. Resultados A prevalência encontrada foi de 2,1 para 1.000.000 recém-nascidos vivos e a frequência de 1,71%, dentre as hiperfenilalaninemias. Quatro casos (40%) com deficiência de 6-piruvoil-tetrahidropterina sintase, três com deficiência de GTP ciclohidrolase I e três com deficiência de dihidropteridina redutase (30% cada um). Seis pacientes foram diagnosticadospor suspeita clínica e quatro pela pesquisa sistemática na triagem neonatal. Após o início do tratamento, os pacientes identificados pela triagem neonatal tiveram melhora rápida e melhor desenvolvimento neuropsicomotor em comparação com aqueles diagnosticados pela história clínica. Conclusões A prevalência das deficiências de BH4 em Minas Gerais foi um pouco maior que a encontrada na literatura, mas a frequência, entre as hiperfenilalaninemias, foi semelhante. Embora raras, são graves e, se não tratadas, levam a atraso de desenvolvimento, movimentos anormais, convulsões e morte precoce. O tratamento precoce (início antes dos 5 meses) mostrou bons resultados na prevenção de deficiência intelectual, justificando a pesquisa dessas deficiências nos recém-nascidos com hiperfenilalaninemia pelos programas de triagem neonatalpara fenilcetonúria.

BH4 deficiency identified in a neonatal screening program for hyperphenylalaninemia.

OBJECTIVES: To show the general prevalence and to characterize tetrahydrobiopterin (BH4) deficiencies with hyperphenylalaninemia, identified by the Neonatal Screening Program of the State of Minas Gerais. METHODS: Descriptive study of patients with BH4 deficiency identified by the Neonatal Screening Program of the State of Minas Gerais. RESULTS: The prevalence found was 2.1 for 1,000,000 live births, with a frequency of 1.71% among hyperphenylalaninemias. There were four cases (40%) with 6-pyruvoyl-tetrahydropterin synthase deficiency, three with GTP cyclohydrolase I - autosomal recessive form deficiency, and three with dihydropteridine reductase deficiency (30% each). Six patients were diagnosed due to clinical suspicion and four cases due to systematic screening in neonatal screening. After the start of the treatment, patients identified by neonatal screening had rapid improvement and improved neuropsychomotor development compared to those diagnosed by the medical history. CONCLUSIONS: The prevalence of BH4 deficiencies in Minas Gerais was slightly higher than that found in the literature, but the frequency among hyperphenylalaninemias was similar. Although rare, they are severe diseases and, if left untreated, lead to developmental delays, abnormal movements, seizures, and premature death. Early treatment onset (starting before 5 months of age) showed good results in preventing intellectual disability, justifying the screening of these deficiencies in newborns with hyperphenylalaninemia identified at the neonatal screening programs for phenylketonuria.

Deficiência de vitamina B12 e fenilcetonúria / Vitamin B 12 deficiency and phenylketonuria

A fenilcetonúria, doença metabólica hereditária, autossômica recessiva, é a mais frequente das aminoacidopatias. Quando não diagnosticada e tratada precocemente, causa retardo mental grave. Os programas de triagem neonatal transformaram a histó- ria natural dessa doença, possibilitando o diagnóstico neonatal e a instituição imediata do tratamento dietético. Atualmente, os pacientes com controle adequado têm vida normal. Nas últimas décadas, alterações nutricionais têm sido relacionadas ao tratamento dietético e aos seus desvios, especialmente após a primeira década de vida. Neste artigo apresenta-se o caso de um adolescente que desenvolveu anemia megaloblástica por deficiente ingestão de vitamina B12 e uma revisão da literatura sobre o tema.(AU)

Phenylketonuria, inherited metabolic disease, autosomal recessive, is the most common of aminoacidopathies. If not diagnosed and treated early, causes severe mental retardation. The newborn screening programs have transformed the natural history of this disease, allowing the neonatal diagnosis and the immediate institution of dietary treatment. Currently, patients with adequate control have normal life. In recent decades, nutritional changes have been related to dietary treatment and its deviations, especially after the first decade of life. In this article we present the case of a teenager who developed megaloblastic anemia due to poor intake of vitamin B12 and a literature review on the topic(AU)

Metabolic syndrome in children and adolescents with phenylketonuria / Síndrome metabólica em crianças e adolescentes com fenilcetonúria

OBJECTIVE: This study aimed to identify markers of metabolic syndrome (MS) in patients with phenylketonuria (PKU). METHODS: This was a cross-sectional study consisting of 58 PKU patients (ages of 4-15 years): 29 patients with excess weight, and 29 with normal weight. The biochemical variables assessed were phenylalanine (phe), total cholesterol, HDL-c, triglycerides, glucose, and basal insulin. The patients had Homeostasis Model Assessment (HOMA) and waist circumference assessed. RESULTS: No inter-group difference was found for phe. Overweight patients had higher levels of triglycerides, basal insulin, and HOMA, but lower concentrations of HDL-cholesterol, when compared to the eutrophic patients. Total cholesterol/HDL-c was significantly higher in the overweight group. A positive correlation between basal insulin level and HOMA with waist circumference was found only in the overweight group. CONCLUSION: The results of this study suggest that patients with PKU and excess weight are potentially vulnerable to the development of metabolic syndrome. Therefore, it is necessary to conduct clinical and laboratory monitoring, aiming to prevent metabolic changes, as well as excessive weight gain and its consequences, particularly cardiovascular risk. .

OBJETIVO: Determinar marcadores bioquímicos da síndrome metabólica em pacientes com PKU. MÉTODOS: Foram avaliados dois grupos de pacientes com PKU, de quatro a 15 anos, com excesso de peso (29) e eutróficos (29). As variáveis bioquímicas avaliadas foram fenilalanina (phe), colesterol total, HDL-c, triglicérides, glicose e insulina basal. Foi determinado o Homa e mensurada a circunferência da cintura. RESULTADOS: As concentrações de phe, de colesterol total e de glicose foram equivalentes entre os grupos. Os pacientes com excesso de peso apresentaram maiores concentrações de triglicérides, de insulina basal, maiores valores da determinação do Homa, menores concentrações de HDL colesterol e valores mais elevados da relação do colesterol total/HDL-c. Houve correlação positiva entre a dosagem de insulina basal e do Homa com a circunferência da cintura nos pacientes do grupo com excesso de peso. CONCLUSÕES: Os resultados deste estudo sugerem que pacientes com PKU e excesso de peso são potencialmente vulneráveis ao desenvolvimento da síndrome metabólica. Há, portanto, necessidade de acompanhamento clínico-laboratorial que previna as alterações metabólicas, o ganho excessivo de peso e as suas consequências, em especial o risco cardiovascular. .

Hereditary fructose intolerance in Brazilian patients.

INTRODUCTION: Hereditary fructose intolerance (HFI) is a rare inborn error of carbohydrate metabolism, autosomal recessive, caused by mutations in the gene ALDOB, leading to deficiency of aldolase B. Symptoms begin in the first months of life with the introduction of complementary foods containing fructose, sucrose or sorbitol, often with vomiting, feeding problems and failure to thrive. Prolonged exposure may cause liver and kidney failure, which can lead to death. Treatment consists in removing the toxic sugars of diet. MATERIALS AND METHODS: Clinical and molecular characterization of four unrelated patients from the State of Minas Gerais, Brazil, all children from non-consanguineous parents. RESULTS AND DISCUSSION: Age at diagnosis was between 10 and 32 months and the severity of the disease correlated with the increasing of age at diagnosis. The predominant symptoms were vomiting, weight loss, and hepatomegaly. Severe renal tubular acidosis manifested in one child. All patients had remission of symptoms after dietary modification. The sequencing of the ALDOB gene identified one homozygous patient for the mutation c.524C > A (p.A175D), while the others were compound heterozygous for c.360_363delCAAA (p.N120KfsX32), c.178C > T (p.R60X) mutations, c.448G > C (p.A150P) and c.524C > A (p.A175D). Clinical improvement of patients after dietary treatment is suggestive of the diagnosis, confirmed by molecular analysis. The prevalence of mutations found in our Brazilian patients is different from those of international literature.

Metabolic syndrome in children and adolescents with phenylketonuria.

OBJECTIVE: This study aimed to identify markers of metabolic syndrome (MS) in patients with phenylketonuria (PKU). METHODS: This was a cross-sectional study consisting of 58 PKU patients (ages of 4-15 years): 29 patients with excess weight, and 29 with normal weight. The biochemical variables assessed were phenylalanine (phe), total cholesterol, HDL-c, triglycerides, glucose, and basal insulin. The patients had Homeostasis Model Assessment (HOMA) and waist circumference assessed. RESULTS: No inter-group difference was found for phe. Overweight patients had higher levels of triglycerides, basal insulin, and HOMA, but lower concentrations of HDL-cholesterol, when compared to the eutrophic patients. Total cholesterol/HDL-c was significantly higher in the overweight group. A positive correlation between basal insulin level and HOMA with waist circumference was found only in the overweight group. CONCLUSION: The results of this study suggest that patients with PKU and excess weight are potentially vulnerable to the development of metabolic syndrome. Therefore, it is necessary to conduct clinical and laboratory monitoring, aiming to prevent metabolic changes, as well as excessive weight gain and its consequences, particularly cardiovascular risk.

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

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. CONCLUSIONS: Selenium supplementation through protein replacement is effective to improve and adapt the nutritional status of selenium in patients with phenylketonuria.

Estado nutricional e ingestão de selênio em crianças com fenilcetonúria em Minas Gerais, Brasil / Selenium intake and nutritional status of children with phenylketonuria in Minas Gerais, Brazil

OBJETIVO: 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 todos os pacientes na segunda fase do estudo, tendo retornado aos limites da normalidade naqueles em que estava alterada. CONCLUSÃO: A complementação de selênio por meio de substituto proteico é eficaz para melhorar e adequar o estado nutricional de selênio em pacientes com fenilcetonúria.

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.

Consumo alimentar de lactentes com fenilcetonúria em uso de aleitamento materno / Nutrient intake of breastfed infants with phenylketonuria

OBJETIVO: O objetivo deste estudo foi avaliar a ingestão de calorias, fenilalanina, tirosina e proteína de lactentes com fenilcetonúria em uso de aleitamento materno. MÉTODOS: Um grupo de 39 crianças, com até 6 meses de idade, que fazia uso de aleitamento materno (grupo amamentado) foi comparado a um grupo-controle que fazia uso de fórmula especial com baixo teor de fenilanina, por meio de um estudo de coorte histórico concorrente. Os grupos foram pareados por sexo e duração da amamentação. Foram revistos 719 recordatórios alimentares de pacientes do grupo amamentado e 628 do grupo-controle. Foi realizada avaliação antropométrica no início e no final do estudo. A análise da ingestão de nutrientes foi feita com a utilização dos programas Minitab e LogXact 4.0, e a avaliação antropométrica foi feita com a utilização do programa Epi Info 6.0. RESULTADOS: O grupo amamentado apresentou ingestão adequada de fenilalanina e tirosina e maior adequação de ingestão proteica e energética. A maioria das crianças dos dois grupos apresentou escore-Z dentro dos limites normais (Z ³-2), com evolução favorável dos indicadores estudados (peso/idade, estatura/idade, peso/estatura e perímetro cefálico). CONCLUSÃO: O aleitamento materno na fenilcetonúria proporcionou ingestão adequada de calorias, fenilalanina, tirosina e proteína. A chance de uma criança do grupo amamentado possuir recordatórios de 24h adequados de ingestão energética foi 10,64 vezes maior que a chance de uma criança do grupo-controle. Em relação à ingestão proteica a chance foi 5,34 vezes maior. O crescimento foi similar nos dois grupos.

OBJECTIVE: This study aimed to assess energy, phenylalanine, tyrosine and protein intakes of breastfed infants with phenylketonuria (breastfed group). METHODS: A retrospective/prospective cohort study was used to compare a group of 39 breastfed infants aged 6 months or less (breastfed group) with a control group being fed a special low-phenylalanine formula. The groups were paired by gender and breastfeeding duration. A total of 719 dietary recalls of the breastfed group and 628 of the control group was reviewed. Anthropometric assessment was done at baseline and end of study. Nutrient intakes were calculated by the software Minitab and LogXact 4.0 and anthropometric assessment was done by the software Epi Info 6.0. RESULTS: The breastfed group presented adequate intake of phenylalanine and tyrosine and more adequate protein and energy intakes than the other group. Most infants, regardless of group, presented z-scores within the normal range (Z ³-2), with good progression of the studied indicators (weight-for-age, height-for-age, weight-for-height and head circumference). CONCLUSION: Breastfeeding of infants with phenylketonuria provided adequate energy, phenylalanine, tyrosine and protein intakes. The likelihood of a child in the breastfeed group to present adequate energy intake was 10.64 times higher than that of a child in the control group. In relation to protein intake, the chance was 5.34 times higher. Both groups presented similar growth.

Fenilcetonúria e a dieta especial: um desafio para a manutenção do peso corporal / Special diet and phenylketonuria: a challenge of body weight maintenance

A fenilcetonúria (PKU), a mais frequente das doenças genético-metabólicas, pode ser encontrada em diversos grupos étnicos, com incidência estimada em 1/21.175 nascidos vivos no estado de Minas Gerais. O tratamento da PKU é dietético e caracterizado pela restrição de fenilalanina (phe) associada ao uso de um substituto proteico – mistura de L-aminoácidos ou hidrolisado proteico – isento ou com traços de phe. No aporte calórico da dieta dos fenilcetonúricos predominam alimentos ricos em carboidratos simples e gorduras. A dieta hipercalórica durante a infância e a adolescência pode conduzir a distúrbios como sobrepeso e obesidade. Estudos indicam, ainda, que crianças com PKU podem ser predispostas à obesidade por apresentarem modificações na composição corporal, levando a alterações no metabolismo basal. Nessa breve revisão são apresentados estudos que demonstram a associação entre fenilcetonúria e excesso de peso...

Phenylketonuria (PKU), the most frequent genetic metabolic diseases can be found invarious ethnic groups, with an estimated incidence of 1/21.175 births in the state of Minas Gerais. The treatment of PKU is dietetic and made by phenilalanina (phe) restriction associated with the use of a protein substitute - a combination of L-amino acids or hydrolyzedprotein - free or with traces of phe. Calorie intake from the diet in PKU is complementedby foods rich in simple carbohydrates and fats. The high calorie diet during childhood and adolescence may lead to disorders like overweight and obesity. Studies also indicatethat children with PKU may be predisposed to obesity because they have changes in bodycomposition, leading to changes in basal metabolism. In this brief review we discussstudies that demonstrate the association between overweight and phenylketonuria...

O aleitamento materno no tratamento de crianças com fenilcetonúria / Breastfeeding in the treatment of children with phenylketonuria

OBJETIVO: Avaliar o efeito do leite materno como fonte de fenilalanina (phe) nos níveis sangüíneos desse aminoácido e no crescimento de fenilcetonúricos. MÉTODOS: Foram estudados 35 fenilcetonúricos que mantiveram leite materno, e os resultados foram comparados com os de 35 lactentes que usaram fórmula láctea comercial. Os grupos foram pareados por sexo e por idade à suspensão do aleitamento materno. Os dados foram analisados até a suspensão do leite materno ou durante 12 meses de acompanhamento. O grupo amamentado recebeu "fórmula especial" isenta em phe, em mamadeira a cada 3 horas, e leite materno em livre demanda nos intervalos. Os níveis sangüíneos de phe, coletados semanalmente até 6 meses e quinzenalmente até 1 ano de idade, foram analisados durante a amamentação. Foram comparados o tempo necessário para adequação dos níveis sangüíneos de phe, após o início do tratamento, utilizando o teste de Wilcoxon e os dados antropométricos, pelo teste t de Student pareado, utilizando o escore z. As dosagens de phe foram analisadas durante a amamentação. RESULTADOS: O tempo mediano para adequação dos níveis de phe no sangue foi de 8 dias para o grupo amamentado e de 7 dias para o grupo controle. As dosagens de phe estavam adequadas em 87 por cento das vezes para o grupo amamentado e em 74,4 por cento para o grupo controle. Na avaliação antropométrica, a maioria das crianças, de ambos os grupos, apresentou escore z > -2. CONCLUSÃO: A manutenção do aleitamento materno, durante o tratamento, mostrou-se adequada no controle metabólico e no crescimento das crianças fenilcetonúricas.

OBJECTIVE: To evaluate the effect of breastmilk as a source of phenylalanine (phe) on levels of this amino acid and on growth in phenylketonuric infants. METHODS: The study recruited 35 breastfed phenylketonuric infants and compared their results with those of 35 infants fed on commercial, milk-based formula. The groups were paired for sex and age at weaning from breastfeeding. Data were analyzed up until cessation of breastmilk or for 12 months' follow-up. The breastfed group were given a "special formula" free of phe, by bottle every 3 hours, and breastmilk at will during the intervals. Levels of phe in the blood, collected weekly up to 6 months and fortnightly up to 1 year de age, were analyzed while breastfeeding continued. The two groups were compared in terms of the time taken for the levels of phe in blood to return to normal after treatment was started, using the Wilcoxon test. Anthropometric data were compared with Student's t paired test in the form of z scores. The phe assays were analyzed throughout breastfeeding. RESULTS: The median time taken for phe levels to return to normal was 8 days for the breastfed group and 7 days for the control group. The phe assay results were normal in 87 percent of tests for the breastfed group and in 74.4 percent for the control group. The majority of children in both groups exhibited a z score > -2 on anthropometric examination. CONCLUSIONS: Continuation of breastfeeding, during the treatment, proved adequate for metabolic control and growth in children with phenylketonuria.

Breastfeeding in the treatment of children with phenylketonuria.

OBJECTIVE: To evaluate the effect of breastmilk as a source of phenylalanine (phe) on levels of this amino acid and on growth in phenylketonuric infants. METHODS: The study recruited 35 breastfed phenylketonuric infants and compared their results with those of 35 infants fed on commercial, milk-based formula. The groups were paired for sex and age at weaning from breastfeeding. Data were analyzed up until cessation of breastmilk or for 12 months' follow-up. The breastfed group were given a "special formula" free of phe, by bottle every 3 hours, and breastmilk at will during the intervals. Levels of phe in the blood, collected weekly up to 6 months and fortnightly up to 1 year de age, were analyzed while breastfeeding continued. The two groups were compared in terms of the time taken for the levels of phe in blood to return to normal after treatment was started, using the Wilcoxon test. Anthropometric data were compared with Student's t paired test in the form of z scores. The phe assays were analyzed throughout breastfeeding. RESULTS: The median time taken for phe levels to return to normal was 8 days for the breastfed group and 7 days for the control group. The phe assay results were normal in 87% of tests for the breastfed group and in 74.4% for the control group. The majority of children in both groups exhibited a z score > -2 on anthropometric examination. CONCLUSIONS: Continuation of breastfeeding, during the treatment, proved adequate for metabolic control and growth in children with phenylketonuria.

Abordagem dietética para fenilcetonúria / A dietetic approach to phenylketonuria

Em Minas Gerais a Triagem Neonatal é realizada pelo Núcleo de Pesquisa em Apoio Diagnóstico (NUPAD) da Faculdade de Medicina da UFMG e os casos detectados são encaminhados para o Serviço Especial de Genética - Ambulatório de Fenilcetonúria, para iniciar o tratamento. O texto aborda a forma como é realizado o tratamento dietético dos fenilcetonúricos, relatando a experiência prática, bem como as tabelas utilizadas com o teor de fenilalanina para controle sérico desse aminoácido.

In the state of Minas Gerais, the Newborn Screening is made by the Núcleo de Pesquisa em Apoio Diagnóstico (NUPAD) at Federal University of Minas Gerais Medical School (Faculdade de Medicina - UFMG). The detected cases are taken for initial treatment in Service Special of Genetic. The text covers the way the dietetic treatment is conducted, incluind the practical experience and the phenylalanine contents charts used for the seric aminoacid control.

Fenilcetonúria / Phenylketonuria

A fenilcetonúria tem sido diagnosticada em nosso meio através dos exames de triagem neonatal, hoje obrigatórios em todo o país. Em Minas Gerais, o teste ("Teste do Pezinho") é realizado há cinco anos pelo Núcleo de Pesquisa em Apoio Diagnóstico (NUPAD) da Faculdade de Medicina - UFMG. Os pacientes com suspeita diagnóstica são encaminhados ao Serviço Especial de Genética do Hospital das Clínicas - UFMG, onde são atendidos por equipe interdisciplinar. Os autores fazem uma atualização sobre a fenilcetonúria, relatando também sua experiência no tratamento destes pacientes, abordando aspectos de diagnóstico diferencial, dietéticos e psicológicos.

Phenylketonuria has been diagnosed by a screening test that is compulsory in Brazil. In Minas Gerais the test has been done, in the last tive years, by Núcleo de Pesquisa em Apoio Diagnóstico (NUPAD) of the School of Medicine - Universidade Federal de Minas Gerais (UFMG). A multidisciplinary team at the Genetics Special Service of the Hospital das Clínicas - UFMG has evaluated the suspected patients. The authors did a review about phenylketonuria relating their experience in the management of these patients in several aspects such as differential diagnosis, dietary and psychological management.