Fat Absorption and Metabolism After Roux-en-Y Gastric Bypass

Study Overview
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Brief Summary
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Using intravenous and oral administration of stable isotope tracers, we will investigate the importance of altered fat absorption and altered whole body fat metabolism for the reduced postprandial systemic TAG concentrations in non-diabetic patients in weight stable phase after RYGB.

Official Title
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Fat Absorption and Metabolism After Roux-en-Y Gastric Bypass

Conditions
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Bariatric Surgery

Intervention / Treatment
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* Other: Metabolic test
* Other: DXA-scan
* Other: MRS
* Other: Feces collection


Participation Criteria
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Eligibility Criteria
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Inclusion criteria, RYGB Age > 18 years RYGB > 12 months prior to inclusion Weight stable (± 3 kg during the last month) HbA1c < 48 mmol/mol before surgery, and no history of diabetes HbA1c < 48 mmol/mol and fasting plasma glucose < 6.1 mmol/l at inclusion Inclusion criteria, CON Age > 18 years No former bariatric surgery Weight stable (± 3 kg during the last month) HbA1c < 48 mmol/mol, fasting plasma glucose < 6.1, and no history of diabetes Exclusion criteria Thyrotoxicosis or inadequately treated hypothyreosis Haemoglobin < 6.5 mmol/l at inclusion Pregnancy (pregnancy test in fertile woman before enrolment) or breast feeding Medication affecting the planned examinations which cannot be paused during the study period. Adherence to extreme diets with excessively high or low contributions from certain macronutrients (e.g. ketogenic diet) Complications restricting eating behavior (e.g. postprandial hypoglycemia, vomiting or strictures) MR contraindications

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Roux-en-Y gastric bypass operated participants<br>Roux-en-Y gastric bypass operated participants in weight stable phase > 1 year from surgery | Other: Metabolic test<br>* Iv and oral administration of stable isotope tracers during fasting and a high-fat liquid mixed meal<br>Other: DXA-scan<br>* Dual energy X-ray Absorptiometry scan of whole-body fat<br>Other: MRS<br>* Magnetic resonance spectroscopy of liver fat content<br>Other: Feces collection<br>* 4-day feces collection<br>|
| Experimental: Control participants<br>Age, sex, and BMI-matched un-operated participants. | Other: Metabolic test<br>* Iv and oral administration of stable isotope tracers during fasting and a high-fat liquid mixed meal<br>Other: DXA-scan<br>* Dual energy X-ray Absorptiometry scan of whole-body fat<br>Other: MRS<br>* Magnetic resonance spectroscopy of liver fat content<br>Other: Feces collection<br>* 4-day feces collection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under the curve of plasma triacylglycerol | During a high-fat liquid mixed meal test | 6 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recovery of oral stable triacylglycerol isotope tracer in feces | An oral stable triacylglycerol isotope tracer will be administered during a high-fat liquid mixed meal test. Feces will be collected the following 4 days to determine the recovery of the tracer in feces. | 4 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fat, triglyceride, triacylglycerol, Roux-en-Y gastric bypass, malabsorption