Doctor: Amel Rezki
Title: Standardised breakfast. A diagnostic tool for glycaemic status and postprandial cardiovascular changes? Comparison with glucose load and cardiovascular investigations with saxagliptin versus placebo in patients with impaired glucose tolerance.
Supervisors: Paul Valensi, Emmanuel Cosson
Doctoral school: ED 146 Doctoral school Galilée, University Sorbonne Paris Nord
Date of thesis defense: 03/2019
Jury: Didier Chapelot
Postprandial metabolic changes are essential both to characterize glycemic status (normal, prediabetes or diabetes, best diagnosed by oral 75g glucose tolerance test of (OGTT)) but also because of cardiovascular changes induced by food intake. A standardized breakfast with 75g carbohydrates (SB) could be an alternative. The continuous glucose monitoring allowed us to show a great concordance of the amplitude / kinetics of the metabolic response (glycemia, insulin resistance indexes, glucose variability) after OGTT vs after SB in obese subjects without known diabetes. The SB also offered good diagnostic performance. We also used the SB to explore fasting and postprandial metabolic and cardiovascular changes (endothelial function, microcirculation, autonomic nervous system, arterial stiffness, myocardial function) in obese patients with impaired glucose tolerance (ACCES study), according to randomiziation to a 12-week treatment with Saxagliptin, a dipeptidyl 4 inhibitor (iDPP4), or its placebo. We showed that this treatment allowed the regression of glucose intolerance for 9 patients out of 10 in the saxagliptin arm against 4 out of 9 in the placebo arm. We did not observe any change in our cardiovascular parameters according to iDPP4 vs placebo, both at fasting and after the SB, after a single dose and after 12 weeks of treatment. Only the decrease in postprandial vagal activity was more sustained in the saxagliptin group.These results support the cardiovascular safety of saxagliptin.To conclude, the SB appears to be a promising diagnostic test for dysglycemia, as it is simple and well tolerated. It can also be used to explore cardiovascular changes after a mixed meal,with more physiological modifications than after OGTT.