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

University of Guelph

Status: Completed

Conditions: Autosomal Recessive Disorder (Genetic Carriers of PKU)

Treatments: Dietary Supplement: L-Phenylalanine

Study type: Interventional

Funder types: Other

Identifiers

NCT05958784

REB23-03-017

Details and patient eligibility

About

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.

Enrollment: 7 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Other

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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7 participants in 1 patient group

Genetic Carriers and Non-Carriers of PKU

Experimental group

Treatment:

Dietary Supplement: L-Phenylalanine