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NCT Number: NCT05471037

Different Limb Lengths in Gastric Bypass Surgery (SLIM) - Part 3: Metabolism and Inflammation

Investigation of underlying metabolic mechanisms and impact on the two surgical procedures on inflammatory factors.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Obesity, Morbid Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

St Clara Research Ltd, St Claraspital Basel

Basel, 4002, Switzerland

About this study

The aim of this project is to investigate underlying metabolic mechanisms in a subpopulation of patients of the SLIM trial, where a laparoscopic proximal Roux-en-Y gastric bypass (LRYGB) with a longer biliopancreatic limb (BPL) is compared to a standard LRYGB. For this purpose, the aim is to examine differences in number of intestinal enteroendocrine cells, subpopulations of intestinal macrophages, and gene expression or DNA-methylation in tissue samples obtained by colonoscopy from the ileum and transverse colon. In addition, gut microbiota (from colon biopsy and fecal samples), meal-stimulated gut hormone profiles, glycemic control, and metabolite patterns (metabolomics; in blood, urine, stool and breath) including plasma bile acid concentrations preoperatively and 6 months post-surgery will be examined. Body composition (fat mass and lean mass) will be measured by means of BIA (bioimpedance analysis; Biacorpus).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 2 x 25 patients with morbid obestiy (BMI of 35 kg/m2 or higher) who comply with the regulatory rules for bariatric surgery in Switzerland (SMOB guidelines) and participate in the SLIM Trial
  • 15 healthy lean controls

Exclusion criteria

  • general contraindications to kind of surgery
  • known or suspected non-compliance
  • inability to follow the procedures of the study, e.g. due to language problems, psychological disorders etc. of the participant
  • participation in another interventional study
  • BMI > 60 kg/m2
  • height < 145 cm
  • CL length of < 180 cm as measured intraoperatively
  • ASA physical status classification > III
  • inflammatory bowel disease
  • diabetes
  • intake of corticosteroids, anti-inflammatory/ immunosuppressive drugs potentially altering immune cells
  • clinical signs of current infection
  • known anemia (e.g. hemoglobin < 110g/L for males, < 100g/L for females)
  • known neutropenia (e.g. leucocyte count < 1.5 x 10^9/L or ANC < 0.5 x 10^9/L)
  • known immunodeficiency, e.g. HIV
  • known vasculitis, collagenosis
  • known adrenal insufficiency and/or substitution with glucocorticoids
  • risky daily alcohol consumption (> 24g/d for males, > 12g/d for females)
  • drug abuse
  • known liver cirrhosis Child B or C
  • known uncontrolled congestive heart failure
  • known uncontrolled malignant disease
  • currently pregnant or breastfeeding

Treatment and study plan

Long Biliopancreatic Limb LRYGB

Procedure

LRYGB with an 180 cm biliopancreatic limb (BPL) and an alimentary limb (AL) of 80 cm.

Short Biliopancreatic Limb LRYGB

Procedure

Standard LRYGB with a 80 cm BPL and a 180 cm long AL.

Primary outcomes

  1. Change in glucose tolerance

    Time frame: pre-OP and 6-8 months post-OP

    Change in glucose tolerance as measured by plasma glucose concentrations at 120 minutes after ingestion of a standardized liquid test meal, pre-OP and 6-8 months post-OP.

Secondary outcomes

  1. glycemic control

    Time frame: pre-OP and 6-8 months post-OP

    Change in glucose variability measured by continuous glucose measurement over 1 week, pre-OP and 6-8 months post-OP.

  2. intestinal glucose absorption rate

    Time frame: pre-OP and 6-8 months post-OP

    Differences in intestinal glucose absorption rate after ingestion of a standardized liquid test meal measured by 3-OMG

  3. gastrointestinal peptides

    Time frame: pre-OP and 6-8 months post-OP

    Differences in the release of gastrointestinal peptides after ingestion of a standardized liquid test meal

  4. intestinal enteroendocrine cells

    Time frame: pre-OP and 6-8 months post-OP

    Differences in number and phenotype (protein expression) of intestinal enteroendocrine cells (from ileum biopsies)

  5. intestinal macrophages

    Time frame: pre-OP and 6-8 months post-OP

    Differences in the number and phenotype (gene expression, methylation) of intestinal macrophages and subpopulations (from colon biopsies)

  6. gut microbiota composition

    Time frame: pre-OP and 6-8 months post-OP

    Differences in gut microbiota composition (from colon biopsy and fecal sample)

  7. bile acids

    Time frame: pre-OP and 6-8 months post-OP

    Differences in bile acids and metabolomic patterns (blood)

  8. inflammatory profile

    Time frame: pre-OP and 6-8 months post-OP

    Differences in inflammatory profile measured by hsCRP in blood

  9. enterocyte gene expression

    Time frame: pre-OP and 6-8 months post-OP

    Differences in enterocyte gene expression or DNA-methylation (tissue samples from ileum biopsies)

  10. appetite-related sensations

    Time frame: pre-OP and 6-8 months post-OP

    Differences in subjective appetite-related sensations (feelings of hunger, prospective food consumption, satiation and fullness) after liquid test meal, assessed with Visual Analog Scales

  11. body composition

    Time frame: pre-OP and 6-8 months post-OP

    Body composition (measured by Bio Impedance Analysis (BIA))

  12. mineral metabolism (blood) 1

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (creatinine) in blood samples.

  13. mineral metabolism (blood) 2

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (phosphate) in blood samples.

  14. mineral metabolism (blood) 3

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (calcium) in blood samples.

  15. mineral metabolism (blood) 4

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (magnesium) in blood samples.

  16. mineral metabolism (blood) 5

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (parathyroid hormone) in blood samples.

  17. mineral metabolism (blood) 6

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (calcidiol) in blood samples.

  18. mineral metabolism (blood) 7

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (calcitriol) in blood samples.

  19. mineral metabolism (blood) 8

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (FGF23) in blood samples.

  20. mineral metabolism (blood) 9

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (desoxypyridinoline) in blood samples.

  21. mineral metabolism (blood) 10

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (bone alkaline phosphatase (bALP)) in blood samples.

  22. mineral metabolism (blood) 11

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (osteocalcin) in blood samples.

  23. mineral metabolism (blood) 12

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (sclerostin) in blood samples.

  24. mineral metabolism (blood) 13

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (P1NP) in blood samples.

  25. mineral metabolism (blood) 14

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (CTX) in blood samples.

  26. mineral metabolism (stool) 1

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (phosphate) in feces samples.

  27. mineral metabolism (stool) 2

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (calcium) in feces samples.

  28. mineral metabolism (stool) 3

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (magnesium) in feces samples.

  29. mineral metabolism (urine) 1

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (creatinine) in urine samples.

  30. mineral metabolism (urine) 2

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (phosphate) in urine samples.

  31. mineral metabolism (urine) 3

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (calcium) in urine samples.

  32. mineral metabolism (urine) 4

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (magnesium) in urine samples.

  33. mineral metabolism (urine) 5

    Time frame: pre-OP and 6-8 months post-OP

    Differences in mineral metabolism parameter (desoxypyridinoline) in urine samples.

  34. metabolomic patterns

    Time frame: pre-OP and 6-8 months post-OP

    Differences in metabolomic patterns assed in blood sample, urine sample, stool sample and exhaled breath.

  35. immune response

    Time frame: pre-OP and 6-8 months post-OP

    Differences in immune response biomarkers in blood measured by a cytokine screening assay

Sponsors and collaborators

Lead sponsor

University Hospital, Basel, Switzerland

Other

Registry information

Official study title

Swiss Multicenter Randomized Controlled Trial on Different Limb Lengths in Gastric Bypass Surgery (SLIM Trial) - Part 3: Metabolic Mechanisms and Inflammatory Response

Acronym: SLIM - Part 3

Important dates

Study start
2022
Primary completion
2026
Study completion
2026
First posted
Jul 22, 2022
Registry last updated
Apr 29, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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