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 and associated factors in children and adolescents with phenylketonuria: a systematic review / Excesso de peso e fatores associados em crianças e adolescentes com fenilcetonúria: uma revisão sistemática

ABSTRACT Objective: To verify the occurrence of overweight in children and adolescents with phenylketonuria and to identify possible causal factors. Data sources: A systematic review was performed in the SciELO, PubMed and VHL databases using the descriptors "Phenylketonurias", "Overweight", "Child" and "Adolescent". Original articles conducted with children and adolescents, published between 2008 and 2018 in Portuguese, English or Spanish languages were included. Data synthesis: A total of 16 articles were identified and, after screening procedures, 6 studies were selected for the review. Overweight in children and adolescents with phenylketonuria was a frequent occurence in the studies included in this review, ranging from 7.8 to 32.6%. The female sex was the most affected by the nutritional disorder. Furthermore, a high caloric intake combined with a lack of stimuli to practice physical activities were main factors associated with the excessive weight in the population of interest. Conclusions: Excess weight can be considered a common outcome in children and adolescents with phenylketonuria. It is mainly caused by inadequate food consumption and sedentary lifestyle. The importance of early identification of nutritional disturbances in children and adolescents with phenylketonuria should be emphasized, in order to prevent associated chronic diseases and to promote health by encouraging continued healthy eating habits and the regular practice of physical exercises.

RESUMO Objetivo: Verificar a ocorrência de excesso de peso em crianças e adolescentes com fenilcetonúria e identificar possíveis fatores causais. Fontes de dados: Revisão sistemática realizada nas bases de dados Scientific Eletronic Library Online (SciELO), Publisher Medline (PubMed) e Biblioteca Virtual em Saúde (BVS) com os descritores "Phenylketonurias", "Overweight", "Child" e "Adolescent". Foram incluídos artigos originais sobre crianças e adolescentes, publicados entre 2008 e 2018 nos idiomas português, inglês ou espanhol. Síntese dos dados: Foram identificados 16 artigos e, após aplicação dos procedimentos de seleção, 6 estudos foram selecionados para compor a revisão. O excesso de peso em crianças e adolescentes com fenilcetonúria foi evento frequente nos estudos incluídos na presente revisão, variando de 7,8 a 32,6%. Aponta-se o sexo feminino como o grupo mais acometido pelo distúrbio nutricional. O principal fator associado ao excesso de peso na população de interesse na população de interesse foi o consumo calórico elevado aliado à falta de estímulos para a prática de atividades físicas. Conclusões: O excesso de peso pode ser considerado um desfecho comum em crianças e adolescentes com fenilcetonúria, sendo ocasionado principalmente pelo consumo alimentar inadequado e pelo sedentarismo. Salienta-se a importância da identificação precoce de agravos nutricionais em crianças e adolescentes fenilcetonúricos, a fim de prevenir doenças crônicas associadas e promover a saúde, com incentivo à manutenção de hábitos alimentares saudáveis e à prática regular de exercícios físicos.

Análise da densidade mineral óssea em pacientes com fenilcetonúria e sua correlação com parâmetros nutricionais / Bone mineral density assessment in patients with phenylketonuria and its correlation with nutritional parameters

Introdução: Redução da densidade mineral óssea (DMO) está associada à Fenilcetonúria (PKU), mas a causa desta associação não é completamente entendida. O objetivo desse estudo foi avaliar a ingestão de nutrientes relacionados ao metabolismo ósseo (cálcio, fósforo, magnésio, potássio), e sua associação com a DMO em pacientes com PKU. Métodos: Estudo transversal, observacional. Foram incluídos 15 pacientes (PKU Clássica=8; Leve=7; mediana de idade=16 anos, IQ=15-20), todos em tratamento com dieta restrita em fenilalanina (Phe) e 13 em uso de fórmula metabólica. Foi realizado recordatório alimentar de 24 horas de um dia e demais dados (histórico de fraturas, parâmetros antropométricos, DMO e níveis plasmáticos de Phe, Tyr, cálcio) foram obtidos por revisão de prontuário. Resultados: Nenhum paciente apresentou histórico de fraturas e seis realizavam suplementação de cálcio (alteração prévia da DMO=5; baixa ingestão=1). A mediana dos níveis de Phe foi 11,6 mg/dL (IQ=9,3-13,3). Em relação ao recordatório alimentar, dez indivíduos apresentaram inadequado consumo de carboidratos; 14, de lipídeos; 9, de cálcio; 11, de magnésio; 13, de fósforo; e todos de potássio. A mediana da DMO foi de 0,989 g/cm2 (IQ=0,903-1,069), sendo duas classificadas como reduzidas para idade, ambas de pacientes com PKU Leve que recebiam suplementação de cálcio. Não foi observada correlação entre níveis de Phe, DMO e demais variáveis analisadas. Conclusão: Redução da DMO não foi frequente na amostra, embora ingestão inadequada de cálcio assim o seja. Estudos adicionais são necessários para esclarecer o efeito da Phe e da ingestão dietética sobre o metabolismo ósseo na PKU. (AU)

Introduction: Reduced bone mineral density (BMD) is associated with phenylketonuria (PKU), but this association is not completely understood. This research aimed to evaluate intake of nutrients related to bone metabolism (calcium, phosphorus, magnesium, potassium) and its association with BMD in patients with PKU. Methods: In this cross-sectional, observational study, 15 patients with PKU (Classical=8, Mild=7; median age=16 years, IQ=15-20 years) were included, all of them on phenylalanine (Phe) restricted diet and 13 being supplemented with a metabolic formula. A 24-hour dietary recall was performed and remaining data (history of fractures, anthropometric parameters, BMD and plasma Phe, tyrosine and calcium levels) were obtained through medical chart review. Results: No patient had any fractures and six received calcium supplements, five due to previous change in BMD and one due to inadequate nutritional intake. Median Phe level was 11.6 mg/dL (IQ=9.3-13.3). In relation to dietary recall, all individuals had inadequate intake of some nutrient (carbohydrate=10; lipids=14; calcium=9; magnesium=11; phosphorus=13; potassium=15). The median BMD was 0.989 g/cm2 (IQ=0.903-1.069). Two cases were classified as low BMD for age, both in patients with mild PKU receiving calcium supplements. Conclusion: Reduced BMD was not common in this sample, although inadequate calcium intake was frequently reported. Additional studies are needed to clarify the effect of Phe and dietary intake on bone metabolism in patients with PKU.(AU)

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.

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)

¿Qué debe saber el pediatra de las hiperfenilalaninemias? / What should the paediatrician know about hyperphenylalaninaemia?

Las hiperfenilalaninemias se definen por un nivel sanguíneo de fenilalanina sobre 2 mg/dl. La principal causa es una mutación en el gen que codifica la fenilalanina hidroxilasa que cataliza la reacción que transforma la fenilalanina en tirosina. Las hiperfenilalaninemias se clasifican en benignas o leves, y las fenilcetonurias en leves, moderadas y clásicas. Debido a que su detección más allá del periodo neonatal causa retardo mental severo, desde 1992 en Chile su detección, junto con la del hipotirodismo congénito, es parte del Programa Nacional de Pesquisa Neonatal. Este artículo pretende responder las preguntas más comunes que se puede hacer el pediatra cuando enfrenta a un paciente con hiperfenilalaninemias.

Hyperphenylalaninaemias are defined by a blood phenylalanine over 2 mg/dl. The main cause is due to a mutation in the gene that codes the phenylalanine hydroxylase that catalyses the reaction that converts phenylalanine into tyrosine. The hyperphenylalaninaemias are classified into benign or mild hyperphenylalaninaemias, or mild, moderate or classic phenylketonurias. Due to its delayed detection outside the neonatal period it causes severe mental retardation. Its detection along with congenital hypothyroidism has been part of the National Neonatal Screening Program since 1992 in Chile. This article aims to answer the most common questions asked by the paediatrician when faced with a patient with hyperphenylalaninaemias.

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. .

Evaluation of somatic development in adult patients with previously undiagnosed and/or untreated phenylketonuria

To evaluate physical growth, development and nutritional status in adults with previously undiagnosed/ untreated phenylketonuria [PKU]. Four hundred adults [201 females and 199 males] with severe intellectual disability who were born prior to compulsory neonatal screening [before 1976] and who resided in social welfare homes in southeastern Poland were screened for PKU. The screening was performed by blood test using a tandem mass spectrometry method [MS/MS] and was confirmed by analysis of organic acids in urine. Eleven were identified as previously undiagnosed and/or Untreated PKU cases. They underwent an assessment of their somatic development/status. Among the 11 PKU patients [4 females and 7 males] the following characteristics were observed: poor physical growth after somatic development [n = 8,2 females aged 23 and 56 years and 6 males aged 28-59 years]; decreased head circumference - microcephaly [n = 5,1 female aged 56 years and 4 males aged 28-59 years]; poor body height [n = 2, 1 female aged 23 years and 1 male aged 59 years]; poor thoracic circumference [n = 9, 3 females aged 23-56 years and 6 males aged 28-59 years]. Overall, body weight imbalance was noted in 9 [81.8%] patients and irregularity of body proportions in 6 [54.5%] patients. Our data showed the importance of nutritional surveillance and impact of metabolic imbalance on physical growth and body stature in untreated PKU patients. We therefore recommend an adequate and individually planned introduction of dietary intervention among that group of patients in order to ameliorate its nutritional status, general fitness and health

A clinical investigation of 228 patients with phenylketonuria in mainland China.

Neonatal screening for phenylketonuria (PKU) in Mainland China was started late and is incomplete. At the present time, it only covers 1-2% of the whole nation. There are about 1,500-2,000 PKU patients born in China annually. In this study, 228 PKU patients who were followed in our hospital were reviewed. Only 19 (8.3%) patients were detected by neonatal screening. Two hundred and nine (91.7%) cases were defined by pediatricians at the age of 1 month to 22 years, among them 94.5% had mental retardation, 48.9% developed epilepsy, and 22.9% gave up the treatment because of financial difficulty and loss of confidence in recovery. To help all of the patients, the only feasible way is the popularization of nationwide screening.

Síndrme de Rett: relato de caso e revisäo bibliográfica / Rett syndrome: a case report and bibliography review

A síndrome de Rett é uma doença degenerativa que acomete meninas, caracterizada por movimentos estereotipados das mäos, padröes respiratórios desordenados e perda das capacidades motora e da linguagem. Os autores descrevem um caso bastante ilustrativo da síndrome de Rett, detectado em uma criança de três anos. O diagnóstico é essencialmente clínico, tendo sido destacados os critérios de Hagberg e os diagnósticos diferenciais para a síndrome

The incidence of phenylketonuria in Thailand.

Phenylketonuria (PKU) is a congenital defect involving failure to metabolize phenylalanine to tyrosine because of the absence of phenylalanine hydroxylase. Untreated PKU causes severe mental retardation, musty odor, hyperactivity, seizures, eczema and hypopigmentation. Without therapy, the child may develop with an IQ of less than 20. Restricting dietary phenylalanine before the onset of brain damage is necessary, to maintain the phenylalanine concentration at 3-8 mg/dl. Thirteen thousand three hundred and ninety-seven mentally retarded outpatients, aged 4 months to 24 years, from the year 1963 to 1987 were studied for PKU. Seven patients had positive PKU test by ferric chloride test and Phenistix, six PKU confirmed by paper chromatography. Two PKU by fluorometry and one PKU by amino acid analyzer. The incidence is 1:1,900 mentally retarded patients or 1:1,200,000 population. So, the incidence seems to be lower than in other countries which have neonatal screening for PKU. Because early diagnosis is essential in order to avoid the severe effects of PKU, neonatal screening has become widespread in the U.S., Australia, Great Britain, and other European Countries. The incidence of 1 PKU out of 1:1,200,000 Thai population seems to be not important enough for initiation of a PKU screening program in Thai newborns.