Phenylketonuria (PKU)
Conditions
Keywords
phenylalanine, obesity, diet
Brief summary
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.
Interventions
None listed
Sponsors
Christel Tran
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Prevalence of overweight and obesity in adult PKU patients | At enrollment | Defined according to WHO BMI categories (overweight: 25.0-29.9 kg/m²; obesity class I-III: ≥30.0 kg/m²) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Dietary adherence in adult PKU patients (self-reported adherence questionnaire) | At enrollment | Measured as the percentage (%) of participants classified as adherent, partially adherent, or non-adherent to dietary treatment. |
| Dietary intake in adult PKU patients (24-hour dietary recall) | At enrollment | Measured as daily intake (continuous variables) including total energy (kcal/day), phenylalanine (mg/day), protein (g/day), carbohydrates (g/day), lipids (g/day), and amino acid mixtures (g/day). |
| Disordered eating behaviors (Eating Disorder Examination Questionnaire, EDE-Q) | At enrollment | Measured as global EDE-Q score (continuous scale). |
| Depressive symptoms (Patient Health Questionnaire-9, PHQ-9) | At enrollment | Measured as total PHQ-9 score (0-27). Higher scores mean worse outcomes |
| Physical activity level (Global Physical Activity Questionnaire, GPAQ) | At enrollment | Measured as total physical activity (Days-hours-minutes/week). Higher scores mean better outcome |
| Plasma phenylalanine levels (metabolic control) | Retrospective (12 months prior to inclusion) | Measured as mean phenylalanine concentration (µmol/L) over the previous 12 months |
| Plasma tyrosine levels | Retrospective (12 months prior to inclusion) | Measured as mean tyrosine concentration (µmol/L) over the previous 12 months |
| Serum total cholesterol levels | Retrospective (12 months prior to inclusion) | Measured as concentration (mmol/L) from available laboratory data. |
| Serum triglyceride levels | Retrospective (12 months prior to inclusion) | Measured as concentration (mmol/L) from available laboratory data. |
| Blood glucose levels | Retrospective (12 months prior to inclusion) | Measured as concentration (mmol/L) from available laboratory data. |
| Thyroid-stimulating hormone (TSH) levels | Retrospective (12 months prior to inclusion) | Measured as concentration (mIU/L) from available laboratory data. |
| Vitamin B12 levels | Retrospective (12 months prior to inclusion) | Measured as concentration (pmol/L) from available laboratory data. |
| Folate (vitamin B9) levels | Retrospective (12 months prior to inclusion) | Measured as concentration (nmol/L) from available laboratory data. |
| Sapropterin treatment exposure | At enrollment | Measured as percentage (%) of participants receiving sapropterin (yes/no). |
Countries
Switzerland
Outcome results
None listed