Validation of a questionnaire to assess eating disorders in inherited metabolic disease patients requiring dietary treatment Investigador: Inês Curvelo Mendes Abstract |
Diet quality and saproterin dihydrochloride (BH4) use in children with phenylketonuria (PKU) Investigador: Maria Inês Gama Abstract Phenylketonuria (PKU) is a rare metabolic disorder. Mutations in the enzyme phenylalanine hydroxylase (PAH), impair phenylalanine (Phe) metabolism into tyrosine, and a Phe build up in the brain causes neurological deterioration and consequently brain damage and developmental delay, if treatment is not initiated early. Treatment consists of a low protein diet restricted in the amino acid Phe. Diet is based on low protein foods, usually fruits and vegetables, together with a protein substitute to secure protein needs and special low protein foods to attain energy requirements. Sapropterin dihydrochloride (BH4), is a synthetic form of the co-factor tetrahydrobiopterin, necessary for the PAH activity. Patients who respond to the drug can increase Phe tolerance, leading to diet relaxation and consequently more natural protein introduction in the diet, and/or can improve metabolic control of patients. However, reports of patients’ food patterns in PKU are scarce, with existing ones reporting increase intake of known familiar foods and neophobia to new protein sourced foods. This could lead to nutritional imbalances, particularly in micronutrient status. A retrospective observational longitudinal study will be performed in a cohort of paediatric (0-17 years) PKU patients followed at the BCH, and their caregivers. Data from patients records (age, gender, diagnosis, weight, height, BMI, metabolic control) food frequency and food neophobia questionnaires will be collected. From caregivers an anxiety and depression questionnaire will be applied. We expect these results to be of extreme importance to characterize food patterns and food choices in children treated with BH4 treatment as well as their caregivers’ burden. Saiba mais |
Bone health and micronutrients status evaluation in phenylalanine dietary restricted patients Investigador: Sandra Mexia Abstract Phenylketonuria (PKU) dietary management involving protein restriction remains an effective treatment of the disease preventing neurocognitive compromise. The goal is to limit the accumulation of toxic amounts of phenylalanine (Phe), an essential amino acid. A combination of natural protein and Phe-free, tyrosine rich formulas are needed to provide adequate amounts of tyrosine for growth and neurotransmitter synthesis, with just enough Phe for anabolism. Although, long term protein restricted diets can lead to suboptimal bonne health outcomes, potentially leading to growth failure and fractures. |
Does phenylalanine restricted diet impacts microbiota in patients with phenylketonuria? Investigador: Catarina Isabel dos Santos Rodrigues. ABSTRACT: Phenylketonuria (PKU) is a rare autosomal recessive inborn error of phenylalanine (Phe) metabolism due to a deficiency of the hepatic-based enzyme phenylalanine hydroxylase. Dietary treatment is the cornerstone of therapy and its goal is to prevent excessive Phe accumulation in the blood. The gut microbiota plays a major role in the maintenance of the host health, including intestinal health and function. It is influenced by several factors, including dietary pattern, antibiotic exposure, mode of delivery of a neonate, among others. However, dietary pattern is one of the most important, as it strongly influences the composition of gut microbiota. This may be particularly relevant in PKU patients, since their special Phe- restricted diet begins in the neonatal period and is maintained throughout life, possibly modifying gut microbiota composition and affecting gut homeostasis. This study aims to i) characterize the gut microbiota of adult PKU patients; ii) compare gut microbiota of adult PKU patients with healthy adult population; and iii) understand the role of the Phe-restricted diet as a potential inducer of gut dysbiosis. This will be an observational, cross-sectional study. A total of 24 participants will be recruited from the National Reference Centre in Hereditary Metabolic Disorders, Centro Hospitalar de Lisboa Norte. Anthropometric data of the population will be collected, and body composition will be assessed by bioimpedance, after overnight fasting. Faecal samples will be collected, as well as food records from the three days prior to faecal sample collection. Data from medical records will also be collected, including prescribed protein substitutes, natural and total daily protein intakes, median blood Phe concentrations in the previous year preceding the study, and clinical relevant data. |
Melhoramento das novas tabelas de composição do teor e dos aminoácidos a utilizar como ferramenta para o tratamento das doenças hereditárias do metabolismo proteico Investigador: Carla Vasconcelos As Doenças Hereditárias do Metabolismo (DHM) são patogênicas raras de natureza genética em que uma metabolização pode ser destruída. A proteína é uma proteína enzimática, que é uma variável via metabólica, tendo uma acumulação de compostos (muitas vezes tóxicos) e uma produção diminuída ou um produto biológico importante (Scriver et al., 2001). A deficiência enzimática é devida a uma mutação numérica de vários genes codificantes para o passo metabólico em causa. Como aminoácidos e ácidos orgânicos, tais como aminoácidos e sob o ponto de vista fisiológico são incluídos no grupo de intoxicação por doenças, ou seja, doenças que causam sintomas de intoxicação aguda e progressiva, por acumulação de metabolismo tóxico ao aumento do bloqueio enzimático. |
The effect of the nitrogen source on metabolism in Phenylketonuria Investigador: Maria João Pena, PhD Student, FMUPorto Since Phenylketonuria’s (PKU) treatment introduction in 1950’s by Dr. Horst Bickel, many advances were made. In fact, one of the major contributions to PKU was the implementation of a phenylalanine (Phe)-restricted diet, remaining the cornerstone of treatment. The Phe-restricted diet consists of natural protein supplemented with protein substitutes (PS). Phe-free amino acid mixtures (AAM) are still the most common PS used to treat patients with PKU, despite the recent emergence of glycomacropeptide-based PS (GMP). GMP is an intact protein derived from cheese making process. There may be metabolic discrepancies between AAM and GMP, particularly at gycidic metabolism level. Several mechanisms can explain these differences, such as, the incretins release and the gut microbiota. Nevertheless, the scientific evidence is still scarce. This project comprises animal and clinical studies. |
Challenges in long-term management of MSUD: a prospective study by assessment of clinical, Biochamical and Anthropometric Parameters Investigador: Sandra Mexia Maple syrup utine disease (MSUD - OMIM # 24860) is a rare unherited sidorder of branched-chain amino acids (BCAAs) - leucine (Leu), isoleucine (lLe) and valine (Val), displaying an autosomal recessive pattern of inheritance, and caused by deficiency of branched-chain aketo acid dehydrogenase, the enzymatic complex responsible for the breaking down of byproducts of the BCAAs transmination reactioin, the corresponding branched-chain a-keto-acids (BCKA). |
Estado de micronutrientes e ingestão de misturas de aminoácidos isentas de fenilalanina, em doentes fenilcetonúricos Investigador: Paula Cristina Ramos |
Elaboração de tabelas com composição quantitativa de aminoácidos e teor proteico de um conjunto de produtos hortícolas e leguminosas de origem nacional a partir da realização de perfil de aminoácidos desses alimentos
Investigador: Carla Vasconcelos Uma das importantes fontes proteicas dos planos alimentares dos doentes com Doenças Hereditárias do Metabolismo Proteico são os produtos hortícolas e as leguminosas. Este estudo procura atualizar os dados referentes às alterações no mercado alimentar português e, simultaneamente, sistematizar essa informação em bases de dados ou tabelas de composição, possibilitando aos doentes uma melhor escolha, em prol da sua saúde. |
Efeito da mistura de aminoácidos livre de fenilalanina em parâmetros metabólicos
Investigador: Maria João Pena Neste estudo procura-se estabelecer relação entre a dieta particular utilizada nos doentes com PKU e alguns parâmetros metabólicos, ainda não estudados nesta patologia. Em particular, pretende-se determinar se a mistura de aminoácidos livre de fenilalanina é responsável pela diminuicão dos níveis plasmaticos de glicose em ratos. |
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