CClinicalTrials.gg
Active, not recruitingNCT009238194XLUpdated Apr 24, 2026

4XL Study - Obesity Surgery in Adolescence

An interventional study of Laparoscopic gastric bypass and Standard conservative treatment in Obesity, Morbid, sponsored by Sykehuset i Vestfold HF. Active, not recruiting at 1 site in Norway. Open to participants aged 13 Years to 18 Years. Per ClinicalTrials.gov, last updated 2026-04-24.

Sponsored by Sykehuset i Vestfold HF · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
120
Allocation
Non-randomized
Ages
13 Years to 18 Years
Sex
All
01

Study summary

The purpose of this study on adolescents between 13 and 18 years of age with morbid obesity is to determine whether surgical treatment gives more health benefits than standard conservative treatment, and if laparoscopic gastric bypass is a method with high safety and a low complication rate.

Read the detailed description

The study has two intervention arms:

Experimental: Group A Surgery; laparoscopic gastric bypass

Active comparator: Group B Patients from Child Obesity Registry of Vestfold who get standard conservative treatment in a multidisiplinary team at Morbid Obesity Center.

All patients are referred to Morbid Obesity Center from other hospitals or general practionairs in Norway. The procedure will take place at the Vestfold Hospital Trust The participants are included for 2 years follow-up with visits to a multidisciplinary team every 3rd month at the Morbid Obesity Center. Total follow-up time is ten years.

02

Conditions studied

  • Obesity, Morbid

Keywords

  • Adolescents
  • Gastric Bypass
  • Quality of Life
  • Mental Health
  • Lifestyle
03

Who can participate

Ages eligible
13 Years to 18 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Between 13 and 18 years of age at inclusion
  • Tanner stage 4-5
  • BMI > 40 kg/m2 or BMI > 35 with at least one comorbidity (type 2-diabetes, obstructive sleep apnea, serious hypertension or cerebral pseudotumor)
  • At least one year multidisciplinary treatment completed

Exclusion criteria

Exclusion Criteria:

  • Tanner stage \< 4
  • Substantial risk for lack of compliance
  • Obesity syndrome (e.g., Prader Willi syndrome)
  • Obesity related to brain damage
  • Serious general disease
  • Monogenic obesity
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
120 participants (estimated)

Study arms

  • Experimental
    Group A

    Laparoscopic Gastric Bypass

    Procedure: Laparoscopic gastric bypass

  • Active comparator
    Group B

    Standard conservative treatment. Patients from Child Obesity Registry of Vestfold.

    Behavioral: Standard conservative treatment

Interventions

  • ProcedureLaparoscopic gastric bypass

    Patients are referred to Morbid Obesity Center from Vestfold Hospital Trust and other hospitals in Norway. The procedure will take place at Morbid Obesity Center, Vestfold Hospital Trust.

  • BehavioralStandard conservative treatment

    Participants from Child Obesity Registry who undergoes conservative treatment at Morbid Obesity Center, Vestfold Hospital Trust.

05

What researchers measure

Primary outcomes

  1. BMI and weight loss

    Surgical or standard conservative treatment

    Time frame: Baseline, Year 1, 2, 5, 10

Secondary outcomes

  1. Quality of Life (KINDL)

    Web-based questionnaire baseline and after 1, 2, 5 and 10 years.

    Time frame: 10 years

  2. Eating Disorders (Child Eating Behavior Questionnaire)

    Web-based questionnaire baseline and after 1, 2, 5 and 10 years.

    Time frame: 10 years

  3. Mental Health (Development and Well-Being Assessment, DAWBA)

    Web-based questionnaire baseline and after 1, 2, 5 and 10 years.

    Time frame: 10 years

  4. Self-Esteem (Rosenberg Self-Esteem scale)

    Web-based questionnaire baseline and after 1, 2, 5 and 10 years.

    Time frame: 10 years

  5. Surgical and Medical Complications

    Web-based questionnaire baseline and after 1, 2, 5 and 10 years.

    Time frame: 10 years

  6. Blood sample results

    Blood tests are biobanked at baseline and after 1, 2, 5 and 10 years.

    Time frame: 10 years

06

Study locations

1 site
  • Morbid Obesity Center, The Hospital of Vestfold, South-Eastern Norway Regional Health Authority
    Tønsberg, 3103, Norway
07

Registry details

Key details

Study ID
NCT00923819
Lead sponsor
Sykehuset i Vestfold HF
Collaborators
The Hospital of Vestfold
Responsible party
Jøran Hjelmesæth (PhD, MD, Sykehuset i Vestfold HF) — Principal investigator
First posted
Jun 18, 2009
Start date
Jun 2009
Primary completion
Aug 2033 (estimated)
Completion
Dec 2035 (estimated)
Last update
Apr 24, 2026

Study contacts

Samira Lekhal, PhD,MD
principal investigator · Vestfold Hospital Trust/The Hospital of Vestfold
Jøran Hjelmesæth, MD, PhD
study chair · Vestfold Hospital Trust/The Hospital of Vestfold

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Start the discussion