The Incretin Secretion in the Gut System Related to the Physiological Stimulus

NCT00994435 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 20

Last updated 2011-03-24

No results posted yet for this study

Summary

Insulin secretion and insulin sensitivity are related with an inverse, hyperbolic function, the so called disposition index, that shows the critical importance of the ß-cell dysfunction for the development of T2DM. A consequence of the hyperbolic relationship is that increased insulin resistance is compensated by up-regulation of insulin secretion, as it happens in obesity. However, when a defective insulin secretion in relation to insulin sensitivity takes place (i.e. reduced disposition index) then impaired glucose tolerance or type 2 diabetes develop. The investigators have recently demonstrated that bilio-pancreatic diversion determines a prompt reversibility of T2DM by normalizing peripheral insulin sensitivity and enhancing ß-cell sensitivity to glucose; these changes occur within few days after surgery, largely before changes in body weight occur. This operation may affect the entero-insular axis function, by diverting nutrients away from the proximal gastro-intestinal tract and by delivering incompletely digested nutrients to the ileum, thus abnormally stimulating the secretion of intestinal incretins. It has been shown that male Wistar rats undergoing three different types of small intestinal surgery, namely ileal transposition (either 10 or 20 cm of lower ileum transposed to mid-duodenum) or 85% jejuno-ileal bypass, showed a sustained post-operative reduction in food intake and a significant change in body weight gain. All experimental groups had a large increase in basal and meal-stimulated enteroglucagon, while the area under the curve of plasma levels of gastrin, gastric inhibitory polypeptide (GIP), insulin and blood glucose were significantly reduced. GIP is produced mainly in the duodenum and jejunum as shown in dogs .The aim of the present study is to investigate the intestinal site of production of incretins in response to intraluminal nutrients stimulation in order to establish the relationship between insulin resistance, insulin hypersecretion and different small intestinal segments in insulin resistance conditions, such as obesity and T2DM. To this purpose a mixed test meal will be infused in the duodenum, proximal jejunum or ileum and glucose uptake and insulin secretion studied, in relation to glucagon and incretin response. Studies are carried out in 20 obese subjects of both sexes, 10 of whom with type 2 diabetes and 10 with normal glucose tolerance.

Conditions

Sponsors & Collaborators

  • Catholic University of the Sacred Heart

    lead OTHER

Principal Investigators

  • Giovanni Ghirlanda, MD · Catholic University

Eligibility

Min Age
30 Years
Max Age
60 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2009-01-31
Primary Completion
2010-07-31
Completion
2011-01-31

Countries

  • Italy

Study Locations

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Entities

Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00994435 on ClinicalTrials.gov