Fructose-induced Intestinal de Novo Lipogenesis

Study Overview
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Brief Summary
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8 healthy volunteers, 8 pre-bypass obese subjects, 8 subjects between 12-18 months post-bypass, and 8 subjects matched to the post-bypass patients will be studied in two sub-studies Sub-study 1) after ingestion of two or three different of the following test-meals: A)cream and whey protein B)cream, whey protein and fructose + 13C6 fructose C)test meal with cream, whey protein, fructose and glucose + 13C6 fructose Their intestinal de novo lipogenesis will be estimated by measuring 13C-palmitate on triglyceride-rich lipoprotein particles associated with apoB48 in blood Sub-study 2) after ingestion of two or three different of the following test-meals: A)cream labelled with 13C6 palmitic acid and whey protein B))cream labelled with 13C6 palmitic acid, whey protein, fructose and glucose Their intestinal de novo lipogenesis will be estimated by measuring 13C-palmitate on triglyceride-rich lipoprotein particles associated with apoB48 in blood in sub-study 1 Their exogenous lipid absorption kinetics will be assessed by measuring 13C palmitate on triglyceride-rich lipoprotein particles associated with apoB48 in sub-study 2

Official Title
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Measure of Intestinal Lipogenesis in Healthy Volunteers and Obese Subjects Before and After Gastroplasty: Modulation by Glucose and Fructose

Conditions
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Obesity

Intervention / Treatment
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* Other: fat+protein meal
* Other: Fat + protein + 13C fructose meal
* Other: Fat+protein+13C fructose+glucose meal
* Other: 13C Fat + whey protein
* Other: 13C Fat + whey protein + glucose+ glucose meal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 18-50 years sex male or female less than 2 kg body weight change over the past 3 months subjects Exclusion Criteria: antidiabetic and hypolipemic drugs alcohol consumption >20g/day severe eating disorders severe psychological problems vegetarian diet or other specific diet consumption of illicit substances pregnancy weight gain or weight loss > 1 kg in the last 3 months

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 50 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| non-obese healthy subjects<br>subjects with BMI<25 and no known disease | Other: fat+protein meal<br>* cream+ whey protein<br>Other: Fat + protein + 13C fructose meal<br>* cream+ whey protein +13C fructose<br>Other: Fat+protein+13C fructose+glucose meal<br>* Cream + whey protein + glucose:13C fructose mixture<br>Other: 13C Fat + whey protein<br>* cream labelled with 13C palmitate + whey protein<br>Other: 13C Fat + whey protein + glucose+ glucose meal<br>* cream labelled with 13C palmitate + whey protein + glucose:fructose mixture<br>|
| post-gastric bypass<br>post-obese subjects 12-48 months after Roux-en-Y gastric bypass | Other: fat+protein meal<br>* cream+ whey protein<br>Other: Fat + protein + 13C fructose meal<br>* cream+ whey protein +13C fructose<br>Other: 13C Fat + whey protein + glucose+ glucose meal<br>* cream labelled with 13C palmitate + whey protein + glucose:fructose mixture<br>|
| matched control subjects<br>Nonobese, healthy subjects of similar age, weight, and gender ratio, than post-bypass subjects | Other: fat+protein meal<br>* cream+ whey protein<br>Other: Fat + protein + 13C fructose meal<br>* cream+ whey protein +13C fructose<br>Other: 13C Fat + whey protein + glucose+ glucose meal<br>* cream labelled with 13C palmitate + whey protein + glucose:fructose mixture<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intestinal de novo lipogenesis (sub-study 1) | Measurement of total TG and 13C palmitate in chylomicrons: The sf >20 fraction of post-prandial blood samples will be prepared, and non-chylomicrons, apoB100-containing lipoprotein will be removes by immuno-affinity chromatography using a specific anti-apoB100 antibody | 0-8-hour post-prandial | 
| Postprandial exogenous, labelled palmitate concentration (sub-study 2) | Measurement of total TG and 13C palmitate in chylomicrons of sf >20 fraction of post-prandial blood samples will be prepared, | 0-8-hour post-prandial | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| post-prandial triglyceride profile (sub-studies 1 and 2 | Triglyceride will be measured in the chylomicron, VLDL, LDL and HDL fractions of post-prandial blood samples | 0-8 hour post-prandial | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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de novo lipogenesis, fructose, roux-en-Y gastric bypass, post-prandial triglycerides