Gastric bypass surgery has in many studies shown total remission of type 2 diabetes as early as 1 - 2 days after surgery and this is before any real weight loss has occurred. This suggest that the remission of the diabetes is due to the direct effect of the operation more that the secondary effect of the weight loss. The reason for the major effect on the glucose metabolism after gastric bypass surgery is still unaccounted for.

This PhD. project will try to unveil some of the mechanisms that could explain the effect of gastric bypass surgery on the glucose metabolism seen in patients with type 2 diabetes.

The hypothesis of the study is that a factor "X" will course the remission of the diabetes. This factor "X" is related to the anatomic changes of the gastro intestinal tract, by eliminating the foods passage through the distal part of the ventricle and the duodenum, in combination with the Roux- en-Y sling.

The PhD. project will consist of clinical trails on patients that will undergo gastric bypass surgery. The studies will take place before and within the 1. week after surgery. The investigators will measure different hormones and adipokines in fast and the postprandial state. To discover possible new proteins the investigators will run proteomic on some samples. All the results will be compared to the same parameter on patients undergoing gastric banding, where the anatomy of the intestine hasn't been changed.

Inclusion Criteria:

• The inclusion criteria in Denmark for undergoing gastric bypass and see the above study and cohort description.
• Well treated hypertension < 145/85. HbA1C <8,5 % and c-peptid> 700pmol/l

Exclusion Criteria:

• In treatment with antidepressive, DPP-4 inhibitors and intreatment for thyroid problems.
• Patients treated with insulin.

Patiens undergoing gastric bypass surgery with or without type 2 diabetes and patients with diabetes undergoing gastric banding