Observational Study of Endothelial Dysfunction in Phenylketonuria

Study Overview
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Brief Summary
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The purpose of this study is to determine whether adolescent and adult patients with phenylketonuria who are on long-term phenylalanine-restricted diet suffer from endothelial dysfunction.

Detailed Description
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The aim of the study is the examination of endothelial dysfunction and oxidative stress markers in adolescent and adult patients with phenylketonuria (PKU), in correlation to phenylalanine values und phenylalanine-restricted diet. 25-50 patients with PKU aged ≥16 years of age and a control group of 25 age- and sex-matched healthy volunteers will be included in the study. Endothelial dysfunction will be measured by venous occlusion plethysmography on the lower legs in the PKU patients and in the control group. Wave velocity, aortic stiffness, and intima media thickness of the common carotid artery will be measured by vicorder and duplex ultrasound scanner in the PKU patients and in the control group. Analyses of phenylalanine metabolites and renal function will be performed only in the PKU patients, analyses of oxidative stress markers in the PKU patients and in the control group. Dietary protocols of the patients with PKU will be calculated for their daily phenylalanine, total protein, and calorie intake. Results of the study will be kept in the medical records and paper case report forms. Data will be analyzed only in pseudonymized form.

Official Title
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Observational, Investigator Initiated, Monocentric Study of the Endothelial Dysfunction in Adolescent and Adult Patients With Phenylketonuria Due to Phenylalanine Hydroxylase Deficiency

Conditions
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Phenylketonuria, Endothelial Dysfunction

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: phenylketonuria due to phenylalanine hydroxylase deficiency age ≥16 years Exclusion Criteria: age <16 years pregnancy or maternity late-treated phenylketonuria phenylketonuria due a defect in BH4 synthesis or BH4 regeneration

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with Phenylketonuria<br>Patients with Phenylketonuria due to phenylalanine hydroxylase deficiency | |
| Control group<br>Control group of healthy volunteers | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-ischaemic venous flow (measured in ml/min) in patients with PKU compared to healthy volunteers |  | 18 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Aortic pulse wave velocity in patients with PKU compared to healthy volunteers. Intima media thickness in patients with PKU compared to healthy volunteers. |  | 18 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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phenylketonuria, endothelial dysfunction, CKD