Nutrition Status of Adults With PKU Before and During Treatment With Pegvaliase

Study Overview
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Brief Summary
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Conduct a prospective, longitudinal study to evaluate nutritional status in adults with phenylketonuria (PKU) before and during treatment with pegvaliase (Palynziq™).

Detailed Description
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The investigators will compare intra-subject change in adults with PKU who follow a protein-restricted diet (protein intake less than the RDA for protein based on weight (0.8 g/kg/day) with or without a PKU medical food) within 90 days of starting pegvaliase (baseline) and 9 and 15 months later. The investigators will collect laboratory measures of nutrition status, anthropometrics, Dual-Energy X-Ray Absorptiometry (DXA) to measure body composition and bone mineral density (BMD), and indirect calorimetry to measure resting energy expenditure (REE). In addition, three-day food records will be obtained to assess protein intake and overall diet quality.

Official Title
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Longitudinal Assessment of Nutrition Status of Adults With PKU Before and During Treatment With Pegvaliase

Conditions
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Phenylketonurias

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of phenylketonuria Aged 18-65 years Following a protein-restricted diet with or without medical food within the last 30 days Routine natural protein intake from food is less than the RDA for protein based on weight (0.8 g/kg/day). If not consuming animal proteins, recommended protein intake is 115% RDA due to lower bioavailability of plant proteins. Within ±90 days of starting treatment with pegvaliase at time of study enrollment Exclusion Criteria: Unable to consent to study Under age 18 or over age 65 years Routine natural protein intake is greater than the RDA for protein (0.8 g/kg/d) within the last 30 days. Females who are currently pregnant or lactating

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intra-subject change in intact and medical food protein intake (grams/day) as reported on three-day food records at months 0, 9, and 15. |  | 15 months | 
| Intra-subject change in serum markers of protein status at months 0, 9, and 15. |  | 15 months | 
| Intra-subject difference in lean body mass (%LBM) from month 0 to 15. |  | 15 months | 
| Intra-subject difference in bone mineral density from month 0 to 15. |  | 15 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intra-subject change in concentrations of serum markers of micronutrient status at months 0, 9, and 15. |  | 15 months | 
| Intra-subject change in serum concentrations of essential fatty acid nutriture at months 0, 9, and 15. |  | 15 months | 
| Intra-subject change in BMI at months 0, 9, and 15. |  | 15 months | 
| Intra-subject change in serum markers of cardiovascular status at months 0, 9, and 15. |  | 15 months | 
| Intra-subject change in emotional eating, cognitive restraint, uncontrolled eating at months 0, 9, and 15. | Three-Factor Eating Questionnaire (TFEQ)-18 is an 18-item questionnaire measured on a four-point scale cognitive restraint (6 items), uncontrolled eating (9 items) and emotional eating (3 items). Responses are measured on a four-point scale and the raw scores for each subscale are transformed to correspond to a 0-100 point scale. Higher scores in the respective scales are indicative of greater cognitive restraint, emotional eating, and uncontrolled eating. | 15 months | 
| Intra-subject change in food neophobia at months 0, 9, and 15. | Food Neophobia Scale, which was adapted for a PKU population, includes nine questions measured on a seven-point scale with a higher total score indicative of greater food neophobia (score range 9-63). | 15 months | 
| Intra-subject change in Epicurean eating tendencies at months 0, 9, and 15. | Epicurean eating tendencies questionnaire includes seven items measured with a seven-point scale (range 7-49). Higher scores indicative of greater Epicurean eating tendencies. | 15 months |