Exenatide‐induced changes in metabolic parameters. Changes in metabolic parameters after administration of placebo (black lines, circles), exenatide (red lines, squares), L‐NMMA (black dashed lines, triangle) or exenatide/L‐NMMA (red dashed lines, downward triangles). Data points represent mean with 95% CI. A) glucose and B) insulin. Statistically significant mean differences of exenatide compared with placebo are indicated as *** (P < 0.001)