Heart Care Info - Heart Disease Prevention & Treatment

Postprandial Insulin Secretion After Gastric Bypass Surgery

JJ Holst - Diabetes, 2011 - Am Diabetes Assoc Given the availability of human studies of the relatively specific and potent glucagon-like peptide (GLP)-1 receptor antagonist exendin (Ex) 939, it was just a question of time for the first study of GLP-1 receptor blockade after gastric bypass surgery to appear. In this issue ...

Given the availability of human studies of the relatively specific and potent glucagon-like peptide (GLP)-1 receptor antagonist exendin (Ex) 9–39, it was just a question of time for the first study of GLP-1 receptor blockade after gastric bypass surgery to appear. In this issue of Diabetes, Salehi et al. (1) report such studies in two groups of individuals previously operated on for obesity with Roux-en-Y gastric bypass (RYGB) surgery: one asymptomatic group and one control group with recurrent hypoglycemia after the operation.

The background is that these operations not only bring about a massive weight loss (reductions in BMI from 52 to 33/32 kg/m2 in the current study), but also bring about resolution of type 2 diabetes, if present, in a high percentage (80–90%) of patients. In the current study, three of twelve individuals in both operated groups had type 2 diabetes before the operation, which was resolved completely in all cases. RYGB was originally conceived as a restrictive and malabsorptive procedure, but actually it is neither. The normal function of the stomach is to retain and process food stuff until allowing a controlled emptying precisely adjusted to the digestive capacity of the proximal intestine. The reservoir is lost after the operation and, in effect, a straight tube is constructed that allows unimpeded passage of ingested nutrients directly to the alimentary limb of the Y-anastomosis and directly onwards to the “common limb,” where nutrients are admixed with digestive secretions and digestion starts. This is nicely illustrated in studies of acetaminophen absorption, which proceeds at a maximal rate immediately upon meal ingestion without the slightest retardation (2). Furthermore, balance studies have documented that there is no malabsorption of macronutrients after RYGB (3 ...