Clinical trial NCT05958784: PKU Carriers Trial (Pilot Study): Impact on Cognition, Mental Health, Blood Pressure and Metabolism
Official title: A Pilot Study for the PKU Carriers Trial: Evaluating the Impact of PKU Carrier Status on Cognition, Mental Health, Blood Pressure and L-phenylalanine Metabolism
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Autosomal Recessive Disorder (Genetic Carriers of PKU)
Lead sponsor: University of Guelph
Sponsor class: OTHER
Collaborators: name: McMaster University
First posted: 2023-07-25
Enrollment: 7
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: OTHER

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.


Eligibility criteria: 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

Primary outcomes:
measure: Stop Signal Reaction Time (Response Inhibition)
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
Secondary outcomes:
measure: Working Memory
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Stop Signal Delay
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Individual Coefficient of Variance (Variability in Reaction Times)
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Phenylalanine Levels
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Tyrosine Levels
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Phenylalanine Metabolites: e.g.phenylethylamine, tyramine, phenylpyruvate, others
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Tyrosine Metabolites: e.g. L-DOPA, dopamine, norepinephrine, epinephrine, p-hydroxyphenylpyruvate, homogentisic acid, fumarate, others
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Mood
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
measure: Blood Pressure
timeFrame: Change from baseline to 1-hour and 2-hours post L-Phe supplementation
Other outcomes:
measure: Chronic Anxiety
timeFrame: Baseline
measure: Chronic Depression
timeFrame: Baseline
measure: Impulsivity
timeFrame: Baseline
measure: Trial-by-trial analysis
timeFrame: Change from baseline to 2-hours post L-Phe supplementation
Locations:
city: Guelph
country: Canada
facility: University of Guelph
state: Ontario
Study officials:
References: