However, in these studies, use of DPP-4 inhibitors was, in general, associated with a higher risk of intestinal obstruction than GLP-1RAs (126, 157, 161, 162), which is surprising given the minimal effect of GIP on gastric emptying and the marginally elevated GLP-1 concentrations observed (54, 163). This evidence concerns the gene GLP1R and intestinal obstruction.