Who may be eligible for the Prevalence and Determinants of Obesity in PKU Patients trial?

Inclusion Criteria: * Confirmed diagnosis of phenylketonuria (PKU) by biochemical and/or molecular testing. * Age ≥ 18 years. * Ability to provide written informed consent. Exclusion Criteria: * Pregnant or lactating women. * Inability to follow the study procedures (e.g., due to language barriers). * Eligible participants who refuse to be informed of any important health concern discovered during the study. * Investigators, their family members, employees, or anyone with a personal link to the investigator other than a doctor-patient relationship.

ClinicalTrials.gov record NCT07703020

Prevalence and Determinants of Obesity in PKU Patients

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 6, 2026

Phenylketonuria Associated With Obesity: a Cross-sectional Pilot Study on Prevalence and Possible Contributive Factors

About this page. This page shows the study's official ClinicalTrials.gov record ↗, with added help to make it easier to understand. We explain medical terms, highlight key details in plain language, and suggest questions you may want to ask the study team.

The record is periodically copied from ClinicalTrials.gov and may lag behind changes. AI summaries are checked by software, not a clinician.Read moreShow less

The official record is written by the study sponsor and published on ClinicalTrials.gov. It may not always reflect the latest changes. Before making any decisions, please confirm important information with the study team and your own healthcare team.

Where you see "AI summary", AI was used to create a plain-language explanation and software checked it against the source. It has not been reviewed by a clinician, so it may contain mistakes or leave out important details.

StatusEnrolling by invitationThe study enrols only people the study team invites, for example patients already at a particular clinic. It is not open to the public.

Study typeObservationalA study in which researchers do not assign participants to a treatment or other intervention. They observe or measure what happens, which may include study visits, tests, questionnaires or a review of medical records.

Age18 years old and older

SexAll

LocationSwitzerland

AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This cross-sectional observational study looks at how common overweight and obesity are in adults with phenylketonuria (PKU) and what factors may be associated with excess weight. Adult PKU patients seen in metabolic centers will have a one-time assessment using medical records, lab data, dietary review, and questionnaires about diet, activity, and mental health. The study compares adults with BMI ≥25 to those with BMI <25 to identify contributing factors.

What it is studying. The study is measuring how many adult PKU patients are overweight or obese and examining associations with diet and dietary adherence, physical activity, psychological symptoms (depression, eating behaviors), metabolic control (plasma phenylalanine and tyrosine), routine lab markers (cholesterol, triglycerides, glucose, vitamins, TSH) and treatment exposure (including sapropterin).

What the researchers hope to learn. To estimate how common overweight and obesity are among adults with PKU and to identify clinical, dietary, behavioral, and metabolic factors that may contribute to excess body weight, informing possible preventive strategies.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

This observational cross-sectional multicenter study aims to assess the prevalence of overweight and obesity in adult patients with phenylketonuria (PKU) and to identify associated risk factors. Adult PKU patients followed in metabolic centers in Switzerland and Austria will be evaluated using clinical data, laboratory parameters, and standardized questionnaires addressing diet, physical activity, and psychological factors. The study seeks to better understand contributors to weight gain in this population to inform preventive strategies.

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

Confirmed diagnosis of phenylketonuria (PKU) by biochemical and/or molecular testing.
Age ≥ 18 years.
Ability to provide written informed consent.

Exclusion criteria

Pregnant or lactating women.
Inability to follow the study procedures (e.g., due to language barriers).
Eligible participants who refuse to be informed of any important health concern discovered during the study.
Investigators, their family members, employees, or anyone with a personal link to the investigator other than a doctor-patient relationship.

Study description and what participation involves

The registry record has no detailed description beyond the summary above.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

Participants take part in a one-time visit that includes measurement of height and weight to determine BMI, completion of standardized questionnaires (physical activity: GPAQ; mood: PHQ-9; eating behaviors: EDE-Q), and a 24-hour dietary recall. Study staff will collect clinical and demographic information, treatment history (for example dietary adherence or sapropterin use), and available retrospective laboratory data (such as plasma phenylalanine and other metabolic or routine blood test results) from medical records. No experimental treatments are given.

How the study is structured. An observational, case-control, cross-sectional study. Adults with PKU are placed into two groups by BMI (overweight/obesity versus normal weight) and undergo a single study visit with standardized questionnaires, a 24-hour dietary recall, and collection of clinical and retrospective laboratory data from the prior 12 months. No treatments are assigned.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

This is an observational study, so the study itself gives no treatment. What would taking part involve for me, and would it change my usual care?
The registry says participants are enrolled by invitation. Who decides who is invited, and how?
The listed sites are in Switzerland. Is any of them reachable for me, and does the study help with travel?
Which of the eligibility criteria would need to be checked with tests before I could join?

More on phenylketonuria

Clinical trials38 trials listed for phenylketonuriaEvery trial the registry lists for phenylketonuria, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in phenylketonuria researchLatest monthly update: September 2026. Includes: Diet supply gaps. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start: Mar 1, 2026
Primary completion: Feb 1, 2028 (estimated)
Study completion: Feb 1, 2029 (estimated)
Target enrollment: 100 participants (estimated)
Last updated on registry: Jul 14, 2026
Data verified: Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor: Christel Tran

Participating sites (1)

Lausanne University Hospital
Lausanne, Canton of Vaud, 1011 · Switzerland

Terms used on this page · explanations by MedicalUpdates.ai

written informed consent: The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
Inclusion Criteria: The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria: The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this website; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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