betaine and Phenylketonurias

betaine has been researched along with Phenylketonurias in 2 studies

glycine betaine : The amino acid betaine derived from glycine.

Phenylketonurias: A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952).

Research

Studies (2)

Authors

Clinical Trials (2)

Trial Overview

Trial Outcomes

Bone-specific Alkaline Phosphatase (BSAP) Plasma Concentration at Day 22

Plasma concentration of BSAP was determined as a measure of bone turnover. (NCT01428258)
Timeframe: day 22 of each dietary treatment

Change in the Plasma Phenylalanine Concentration of PKU Subjects Fed the Glycomacropeptide Diet Compared With the Change When Fed the Amino Acid Diet

Plasma will be collected at each base week and after 3 weeks on each of the dietary treatments, glycomacropeptide and amino acid, following an overnight fast. Plasma phenylalanine concentration (along with the complete profile of free amino acids) will be determined with an amino acid analyzer in the Wisconsin State Lab of Hygiene. Statistical analysis to determine the significance of the change in plasma phe concentration when comparing the 2 diets will consist of ANCOVA with covariates for baseline Phe and dietary Phe intake. The change in plasma Phe concentration from day 22 (final) to day 1 (baseline) was determined after adjusting for baseline Phe level and dietary Phe intake. (NCT01428258)
Timeframe: baseline to day 22 on each diet

Comparison of Phe Concentrations in Plasma With Concentrations in Dried Blood Spots

Concentrations of Phe in plasma and in dried blood spots collected simultaneously by subjects will be compared using 2 methodologies, regardless of intervention. At each of the 4 study visits (baseline and final for each dietary treatment): 1) venipuncture was used to collect blood and plasma was isolated and analyzed for Phe with ion exchange chromatography and 2) subjects were asked right after the venipuncture to spot their blood on filter paper for analysis of Phe with tandem mass spectroscopy (MS/MS). The discrepancy in Phe concentrations with these 2 methods was compared for each sample pair using Bland-Altman statistical analysis. Each subject should have had 4 sample pairs, 29 x 4 = 116, but we ended up with only 110 sample pairs, as explained below. (NCT01428258)
Timeframe: 4 times total, 2 per treatment

Dietary Compliance

Compliance with the glycomacropeptide and amino acid dietary treatments will be assessed by comparison of the intake of medical food in grams of protein from medical food per day based on subject completion of 3-day food records prior to the final study visit on day 22. Statistical analysis for a dietary treatment effect will consist of ANOVA. (NCT01428258)
Timeframe: 3 week dietary treatment

Executive Function Assessed by BRIEF

Completion of a standardized test, the Behavior Rating Inventory of Executive Function (BRIEF), by each subject for the GMP diet and the AA diet. Values are T-scores which have a mean of 50 points and a SD of 10 points. A T score of <50 is considered within the normative range. Data are analyzed with a paired t-test. (NCT01428258)
Timeframe: day 22 of each dietary treatment

N-terminal Telopeptide (NTX) Plasma Concentration at Day 22

Plasma concentration of NTX was determined as a measure of bone resorption; higher levels indicate greater bone breakdown (NCT01428258)
Timeframe: day 22 of each dietary treatment

Vitamin D (25-OH) Plasma Concentration at Day 22

Vitamin D was measured as a measure of the capacity for calcium absorption. Higher levels of plasma vitamin D are consistent with higher calcium absorption. (NCT01428258)
Timeframe: day 22 of each dietary treatment

Trials

1 trial available for betaine and Phenylketonurias

Other Studies

1 other study available for betaine and Phenylketonurias