Phenylketonuria
Conditions
Keywords
Phenylketonuria, PKU, Phenylalanine metabolism, Protein requirements, Indicator Amino acid Oxidation, Stable isotopes, GMP, Glycomacropeptide
Brief summary
Phenylketonuria (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.
Interventions
DIETARY_SUPPLEMENTFree amino acids intake
Oral consumption of eight hourly experimental meals- -4 tracer free experimental meals containing a mixture of free amino acids and calories from protein free flavoured liquid, protein free cookies and corn oil -4 isotopically labeled experimental meals. The same protocol will be repeated with glycomacropeptide (GMP).
Sponsors
Vitaflo International, Ltd
University of British Columbia
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
19 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
-Adults more than 19 years of age who are diagnosed with PKU and clinically stable with no acute illness
Exclusion criteria
* Adults with PKU under age 19 year * Adults diagnosed with PKU but are currently ill with a fever or cold
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 13 Co2 production | 8 hours (1 study day). 3 samples will collected as a baseline prior to isotope protocol and 6 samples after 2 hours and 30 minutes of starting the tracer protocol. Data will be reported an average of 2 years. | Breath samples will be collected during the study to measure the rate of oxidation of tracer in the expired breath. |
| Lysine flux | 8 hours (1 study day). 1 sample will collected as a baseline prior to isotope protocol and 2 samples after 2 hours and 30 minutes of starting the tracer protocol. Data will be reported an average of 2 years. | Urine samples will be collected during the study to measure the flux enrichment in urine. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Phenylalanine concentrations | One sample (at 6th meal) after starting of the tracer protocol. Data will be reported an average of 2 years. | Phenylalanine concentrations will be measured in blood. |
| Tyrosine concentrations | One sample (at 6th meal) after starting of the tracer protocol. Data will be reported an average of 2 years. | Tyrosine concentrations will be measured in blood. |
| 16 other amino acids | One sample (at 6th meal) after starting of the tracer protocol. Data will be reported an average of 2 years. | 16 other amino acids will be measured in blood. |
Countries
Canada
Outcome results
None listed