RESUMO
Abstract The mainstay of management of phenylketonuria (PKU) is restriction of dietary phenylalanine (Phe) intake. The present study sought to assess the perception and understanding of health care providers and lay users (patients/family members/caregivers) regarding the national reference database for checking the Phe content of foods, provided by the Brazilian Health Regulatory Agency (Anvisa), whose data are presented in the Table of Phenylalanine Content of Foods (TCFA-Anvisa) and recently in the Phenylalanine Content of Foods Dashboard (PCCFA-Anvisa); and to identify factors which interfere with the usability of these resources. Two online questionnaires, one for providers (n=33) and another for lay users (n=194), were used to collect sociodemographic information, knowledge about dietary management of PKU, sources of information about the Phe content of foods, and perception and understanding of the Anvisa tools. TCFA-Anvisa and PCCFA-Anvisa were not used as main sources of information by either group. Among the participants who had used these tools (15 providers;35 lay users), most considered the PCCFA-Anvisa to be superior or partially superior to the TCFA-Anvisa. The main limitations reported were related to layout and limited variety of foods. We suggest that the limitations identified in this study be considered for future improvement of these resources.
RESUMO
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)