Glucose Metabolism Parameters and Post-Prandial GLP-1 and GLP-2 Release Largely Vary in Several Distinct Situations: a Controlled Comparison Among Individuals with Crohn's Disease and Individuals with Obesity Before and After Bariatric Surgery

Background: This study aims to compare the post-prandial curves of glucose, insulin, GLP-1, and GLP-2 among individuals with Crohn's disease (CD), obese individuals before and after bariatric surgery, and healthy controls.

Methods: This an exploratory cross-sectional study that involved five groups of patients (two groups of individuals with CD-active and inactive), bariatric patients (pre- and post-surgery, who were their own controls), and a distinct separated control group of healthy volunteers. C-reactive protein (CRP) levels and the post-prandial curves of glucose, insulin, GLP-1, and GLP-2 curves were assessed and compared.

Results: The pre-RYGB group presented significantly higher levels of CRP than the post-RYGB (p = 0.001) and the control group (p = 0.001). The inactive CD group presented a higher post-prandial GLP-1 area under the curve (AUC) than the pre-RYGB group (p = 0.009). The post-RYGB group presented significantly higher AUCs of GLP-2 than the pre-RYGB group (p < 0.0001), both inactive and active CD groups (p < 0.0001 in both situations), and the control group (p = 0.002). The pre-RYGB group presented a significantly higher AUC of glucose than the post-RYGB (p = 0.02) and both active and inactive CD groups (p = 0.019 and p = 0.046, respectively). The pre-RYGB group presented a significantly higher AUC of insulin than the control (p = 0.005) and both CD groups (p < 0.0001).

Conclusions: Obesity is associated with an inflammatory state comparable to the one observed in CD; inflammation may also be enrolled in the blockade of GLP-2. CD individuals present a more incretin-driven pattern of glucose metabolism, as a way to prevent hypoglycemia and compensate the carbohydrate malabsorption and GLP-2 blockade.