Although GLP-1 has been suggested as a major factor for the marked improvement of glucose tolerance commonly seen after sleeve gastrectomy (SG), several observations challenge this hypothesis. To better understand the role of GLP-1 in the remission of T2DM long-term after SG in humans, we conducted two separate cross-sectional studies: (1) the GLP-1 response to a standardized mixed liquid meal (SMLM) was compared in subjects with T2DM antedating SG but with different long-term (>2 years) T2DM outcomes (remission, relapse, or lack of remission), and (2) the effect of GLP-1 receptor blockade with Exendin 9-39 on glucose tolerance was examined in subjects with T2DM antedating surgery, who had undergone SG and presented with long-term T2DM remission. In Study 1, we observed a comparable GLP-1 response to the SMLM regardless of the post-SG outcome of T2DM. In Study 2, the blockade of GLP-1 action resulted in impaired insulin secretion but limited deterioration of glucose tolerance. Thus, our data suggest the enhanced GLP-1 secretion observed long-term after SG is neither sufficient nor critical to maintain normal glucose tolerance in subjects with T2DM antedating the surgery.
- Received February 28, 2014.
- Accepted May 15, 2014.
- © 2014 by the American Diabetes Association.
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