Starches Digestion After Obesity Surgery.
Condition: Obesity
MeSH terms: Obesity
Study type: Interventional

Summary: 
      Despite an impressive capacity to induce diabetes remissions, the gastric bypass surgery has
      been associated with the onset of hyperglycemic peaks, which are very intensive and
      transient, in formally non diabetic patients. The aim of this study is to study the digestion
      of starch as compared to that of glucose (same glucose load) before and after gastric bypass
      surgery in obese patients.

      Volunteers will be recruited among the candidates to a gastric bypass, and will be studied
      before and 3 months after surgery. They will have on each occasion 2 random meals,
      corresponding to 30g glucose, one made of starch the other made of glucose, both naturally
      labeled with 13C. The digestion of starch will be assessed with the increase in the plasma
      13C-glucose tracer. Plasma samples will be collected for 3 hours.

      Some studies have already investigated time of absorption of glucose, but any study has
      examined the time of digestion of glucose. Other study always used glucose syrup, so they
      cannot have results about digestion. It is the reason why, in this study, glucose syrup and a
      starch meal will be taken by the same patient and glycaemia will be compared. In this way,
      results will be obtained about the kinetic of digestion of starch.
    

Detailed description: 
      Despite an impressive capacity to induce diabetes remissions, the gastric bypass surgery has
      been associated with the onset of hyperglycemic peaks, which are very intensive and
      transient, in formally non diabetic patients. The aim of this study is to study the digestion
      of starch as compared to that of glucose (same glucose load) before and after gastric bypass
      surgery in obese patients.

      Volunteers will be recruited among the candidates to a gastric bypass, and will be studied
      before and 3 months after surgery. They will have on each occasion 2 random meals,
      corresponding to 30g glucose, one made of starch the other made of glucose, both naturally
      labeled with 13C. The digestion of starch will be assessed with the increase in the plasma
      13C-glucose tracer. Plasma samples will be collected for 3 hours.

      Some studies have already investigated time of absorption of glucose, but any study has
      examined the time of digestion of glucose. Other study always used glucose syrup, so they
      cannot have results about digestion. It is the reason why, in this study, glucose syrup and a
      starch meal will be taken by the same patient and glycaemia will be compared. In this way,
      results will be obtained about the kinetic of digestion of starch.

      All patients will have two evaluations: one before the bypass surgery and one 3 months after.
      All evaluation will include 2 standard meals. Patients have to be fasted, and they will take
      in a randomized order the same glucose quantity: 30g, for the breakfast. After each meal,
      blood sample will be collected during 3 hours at time 0, 10, 20, 30, 40, 50, 60 minutes and
      every 30 minutes until time 180.

      The starch meal will provide 30g of glucose in the form of corn starch. It will be consumed
      in 15 minutes. They are any other food in the meal. This quantity is corresponding to what
      patients can ingest after a bypass surgery, because of the poor size of their stomach.
      C13-carbon is a natural tracer into the corn. The measure of the increase of C13-glucose in
      the plasma is showing the appearance of the tracer, corresponding to the starch digestion.

      The second meal is composed by 30g of corn glucose (glucose-meal), in liquid form and will be
      dived in 3 portions to be ingested in 15 minutes, like the starch meal. They are any other
      food in the meal.
    

Intervention name(s): First starch meal then meal with glucose syrup; First meal with glucose syrup then starch meal
Intervention type(s): Other; Other
Intervention description(s): Before bypass surgery, patients will take randomized meal. One day a starch meal and another day a glucose syrup meal. 3 months after surgery, they will take these 2 randomized meal again, one day the first one, and the day after the other one.; Before bypass surgery, patients will take randomized meal. One day a meal with glucose syrup and another day a starch meal. 3 months after surgery, they will take these 2 randomized meal again, one day the first one, and the day after the other one.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Glucose digestion; Bypass surgery; C13-glucose tracer; Insulin secretion