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PKU Carriers Trial (Pilot Study): Impact on Cognition, Mental Health, Blood Pressure and Metabolism

Not Applicable
Completed
Conditions
Autosomal Recessive Disorder (Genetic Carriers of PKU)
Interventions
Dietary Supplement: L-Phenylalanine
Registration Number
NCT05958784
Lead Sponsor
University of Guelph
Brief Summary

This is a clinical intervention pilot/feasibility study of PKU carriers (cases) and non-carriers (controls). Upon completing the informed consent process, participants will complete baseline measures of chronic mental health prior to the intervention (PHQ-9, GAD-7, BIS-Brief). Participants will attend the Human Nutraceutical Research Unit (HNRU) at the University of Guelph, fasted, and first undergo baseline measures of cognition and acute mental health (mood) and provide samples or saliva, urine and dried blood spots to evaluate phenylalanine (Phe), tyrosine (Tyr) and their metabolites (PAH pathway functioning). Participants will also complete a brief questionnaire which will include age, sex, ethnicity, income, weight and height (measured using a stadiometer and calibrated weigh scale), and confirmation that participants arrived to the lab fasted (i.e. have only had water to drink and no other foods/beverages prior to analyses). Blood pressure will also be measured at baseline. Following baseline tests, participants will consume a pure L-Phe supplement dosed at 100 mg/kg mixed into 250 mL water with 1 tsp white sugar. Blood pressure will be repeated at 1-hour post-L-Phe consumption. Two-hours postprandial, participants will repeat the cognitive tests and acute mental health (mood) assessment, blood pressure measurement and provide follow-up saliva, urine and dried blood spot samples. Participants will also be asked to report any side effects they experienced with the L-Phe consumption.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
7
Inclusion Criteria
  • Known carrier or non-carrier of PKU
  • At least 18 years of age
  • Comfortable fasting the morning of the study (no food or drink other than water)
Exclusion Criteria
  • Diagnosed with: PKU, severe neurodegenerative conditions affecting cognition (e.g. Alzheimer's, Parkinson's, dementia), melanoma, hypertension, liver disease and/or kidney disease
  • Taking a Monoamine Oxidase Inhibitor anti-depressant
  • Pregnant or breastfeeding

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Genetic Carriers and Non-Carriers of PKUL-Phenylalanine-
Primary Outcome Measures
NameTimeMethod
Stop Signal Reaction Time (Response Inhibition)Change from baseline to 2-hours post L-Phe supplementation
Secondary Outcome Measures
NameTimeMethod
Stop Signal DelayChange from baseline to 2-hours post L-Phe supplementation

Stop Signal Task Outcome

MoodChange from baseline to 2-hours post L-Phe supplementation

Profile of Mood States (POMS) Outcome

Individual Coefficient of Variance (Variability in Reaction Times)Change from baseline to 2-hours post L-Phe supplementation

Stop Signal Task Outcome

Phenylalanine LevelsChange from baseline to 2-hours post L-Phe supplementation
Blood PressureChange from baseline to 1-hour and 2-hours post L-Phe supplementation

Systolic and Diastolic

Working MemoryChange from baseline to 2-hours post L-Phe supplementation

N-Back Test Outcome

Tyrosine LevelsChange from baseline to 2-hours post L-Phe supplementation
Tyrosine Metabolites: e.g. L-DOPA, dopamine, norepinephrine, epinephrine, p-hydroxyphenylpyruvate, homogentisic acid, fumarate, othersChange from baseline to 2-hours post L-Phe supplementation
Phenylalanine Metabolites: e.g.phenylethylamine, tyramine, phenylpyruvate, othersChange from baseline to 2-hours post L-Phe supplementation

Trial Locations

Locations (1)

University of Guelph

🇨🇦

Guelph, Ontario, Canada

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