Can pre-surgery lean (fat-free) mass predict weight loss after Roux-en-Y gastric bypass?
Can Pre-operative Lean Mass Predict Weight Loss After Roux-en-Y Gastric Bypass?
This project will see if the amount of lean (fat-free) mass before surgery predicts how much weight people with morbid obesity lose in the two years after Roux-en-Y gastric bypass.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 91 (estimated) |
| Sex | All |
| Sponsor | University Hospital, Geneva Academic / other |
| Locations | 1 site (Geneva, Canton of Geneva) |
| Trial ID | NCT07565051 on ClinicalTrials.gov |
What this trial studies
This is a prospective observational cohort (with retrospective data included) of adults undergoing or previously treated with Roux-en-Y gastric bypass at Geneva University Hospitals. Investigators will measure preoperative body composition (BIA and DXA), handgrip strength, resting energy expenditure, eating and activity questionnaires, clinical labs, and routinely collected anthropometrics. These measures and questionnaires will be repeated at scheduled follow-ups up to two years after surgery, and blood/tissue samples will be banked. The primary analysis will correlate preoperative fat-free mass with weight change over the two-year postoperative period.
Who should consider this trial
Good fit: Adults (≥18) who meet Swiss criteria for Roux-en-Y gastric bypass (BMI≥35 with prior weight-loss program failure or higher BMI criteria), are scheduled for or previously had RYGB at Geneva University Hospitals with follow-up there, can consent and understand French.
Not a fit: People who are not having RYGB, who cannot consent, who plan a different bariatric procedure, or who have contraindications such as active cancer, severe psychiatric disease, substance abuse, or advanced kidney failure are unlikely to benefit from the study's findings.
Why it matters
Potential benefit: If successful, the results could help personalize preoperative counseling and postoperative nutrition/rehabilitation to improve weight-loss outcomes.
How similar studies have performed: Prior observational work on preoperative lean mass as a predictor of bariatric weight loss has produced mixed results, so this approach builds on existing but inconsistent evidence rather than being wholly novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Patients ≥ 18 years AND * Meeting inclusion criteria for RYGB (www.smob.ch): BMI ≥35 kg/m2, failure of weight-reducing programs over 2 years (for patients with a BMI ≥50 kg/m2, 1 year), understanding of the necessity to change the lifestyle and eating habits post-operatively, signed consent for lifelong post-operative follow-up in a recognized bariatric center AND * Scheduled RYGB at the HUG OR previous RYGB at the HUG with a present follow-up in Clinical Nutrition and dietetics at the HUG AND * Understanding French Exclusion Criteria: * Inability or refusal to give consent. * Planification for another type of bariatric surgery than RYGB * Contra-indications to bariatric surgery as stated under www.smob.ch: insufficient nutritional knowledge in nutrition to lose weight, pregnancy, kidney failure (Creatinine ≥ 300 umol/l without dialysis, Crohn's disease, active cancer or remission \< 2 years, active psychiatric disease, substance abuse (alcohol, cannabis, opioids), absence of compliance, lack of understanding of the requirements and necessary lifestyle changes reported by physician or dietician.
Where this trial is running
Geneva, Canton of Geneva
- Geneva University Hospitals — Geneva, Canton of Geneva, Switzerland (Recruiting)
Study contacts
- Study coordinator: Laurence Genton, MD
- Email: laurence.genton@hug.ch
- Phone: 0041 79 553 34 84
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.