Nutritional Status in Phenylketonuria
PhenylketonuriasIn the era of Phenylketonuria (PKU) newborn screening, early diagnosis in the neonatal period and prompt treatment institution has protected patients from developing severe and irreversible mental retardation. The main objective of the treatment is to prevent a chronic elevation of blood Phe concentrations, which together with reduced tyrosine concentrations may increase the risk of neurologic damage. In order to achieve this purpose, the mainstay of treatment is a special diet characterized by a natural protein restriction, supplemented with protein substitutes and special low protein foods. The requirement to optimize growth and body composition, usually result in dietary prescriptions that are high in carbohydrate (>60% of energy intake), to promote anabolism, considering the synthetic properties of this special diet. Some studies have described a high risk of developing overweight and obesity. Although there is a tendency for a higher incidence in females, it seems that the prevalence in PKU patients follows the same trend as the general population. However, there are limited studies published so far and no longitudinal studies are available describing current practice and its impact on the prevalence of overweight and obesity; neither its consequences in terms of metabolic syndrome or cardiometabolic markers. Recently, sapropterin dihydrochloride, which is the synthetic form of Phenylalanine Hydroxylase cofactor, is available in Portugal for patients with PKU. In practice, the sapropterin treated patients increase their natural protein intake, minimizing the synthetic characteristics of the diet. While there is a need for patient re-education about the practicalities of meeting their nutritional needs, scientific evidence about the nutritional status impact of diet liberalization is inadequate. This study aims to test the following hypothesis: Global nutritional status is not significantly affected in patients with PKU under exclusive dietary treatment. There is a trend for increased rates of overweight and obesity in patients with PKU from 2009 and we consider this will continue to increase. The start of sapropterin treatment allows a higher natural protein intake in patients with PKU that significantly targets nutritional status in at least one of its components (anthropometry, body composition or biochemistry).
A Phase 3 Substudy to Evaluate Executive Function in Adults With PKU Who Are Participating in the...
PhenylketonuriaA Phase 3 substudy to evaluate executive function in adults with phenylketonuria who are participating in the phase 3 Study, 165-302. Approximately 100 subjects, aged ≥ 18 to ≤ 70 years old, with PKU will be enrolled.
Protein Requirements in Adults With Phenylketonuria (PKU)
PhenylketonuriaPhenylketonuria (PKU) is an inherited inborn error of phenylalanine (PHE) metabolism caused by decreased activity of phenylalanine hydroxylase (PAH) enzyme. Therefore, PHE accumulates in plasma leading to mental problems. Treatment is a phenylalanine-restricted diet with sufficient protein. However, the optimum protein requirements are still unknown and compliance with diet is not satisfactory in PKU adults. A Previously established technique called indicator amino acid oxidation (IAAO) will be used to determine protein requirements from amino acid based formula vs. glycomacropeptide (GMP) in adults with PKU (≥ 19y). This study will help treat adults with enough protein ensuring maintenance of health.
Body Composition, Energy Intake and Expenditure in People With Phenylketonuria
Phenylketonuria (PKU)This will be case-control study investigating whether dietary intake and components of energy expenditure such as Basal metabolic rate (BMR), physical activity energy expenditure (PAEE) and diet induce thermogenesis (DIT) are different between people with phenylketonuria (PKU) and matched healthy controls. Participants will be children and adults with PKU age between 10 to 45 years old, free from history of any acute and chronic illness. Participants will attend the Metabolic Research Unit at New Lister Building (NLB) after 12-hour overnight fasting refraining from alcohol consumption for at least 24 hours. Any planned exercise will be avoided during the 48 hours prior visit to the Metabolic Research Unit. Height, body weight and handgrip strength will be measured upon arrival at the unit. BMR will be assessed and participants will be asked to provide baseline saliva sample followed by consumption of 8 g deuterium water (D2O) diluted in drinking water. Normal or PKU-type isocaloric breakfast meal will then be provided based on intervention group-type. DIT will be measured 5 times for 3 hours, with each measurement lasting for 20 minutes. Two saliva samples will be collected at 3 and 3.5 hours after ingestion of D2O. Participants will be asked to perform an incremental intensity exercise test for 20 minutes on the treadmill during which expired air will be collected and accelerometer counts and heart rate will be measured. Participants will then be trained on how to recorded food intake and how to use accelerometers for habitual physical activity measurements. PKU participants (and their parents if ≤15 years old) will be asked to complete quality of life (QoL) questionnaires. Participants will be required to wear the accelerometer equipment for seven consecutive days excluding bedtime and keep a record of non-wear times. During these days, they will also prospectively record estimated food and beverages intake over four days including one weekend day.
Early Dietary Treated Patients With Phenylketonuria Can Achieve Normal Growth and Mental Development....
PhenylketonuriasThe study aim is to follow up body growth(body weight by kg, length by cm, head circumference, abdominal circumference, and body mass index ) and mental development of infants on phenylalanine restricted diet in comparison with normal matchable infants.
A Study Into the Future Cardiovascular Disease (CVD) Risk of Phenylketonuria (PKU) Patients on a...
PhenylketonuriasCardiovascular DiseasesThis study will assess the cardiovascular disease (CVD) risk in Phenylketonuria (PKU) patients on a low-phenylalanine diet (LPD). Ultrasound tests, diet information and routine blood samples will be collected once per patient at their next outpatient appointment. 32 adults with PKU will be studied and compared to reference data for healthy people. The results will show if the PKU CVD risk differs from healthy people, and if CVD risk varies within people with PKU.
Acceptability and Tolerance of a Ready-to-use Protein Substitute in Tablet Form for the Dietary...
PhenylketonuriasHyperphenylalaninaemia1 moreThe purpose of this prospective, observational study is to evaluate the tolerability and acceptability of phenylalanine-free protein substitute tablets for young children with PKU aged of 7 years or older.