GLP-1 Secretion Did Not Affect Pancreatic Amylase, Lipase Plasma Concentrations

Endogenous levels of glucagon-like peptide (GLP)-1 do not seem to affect plasma concentrations of pancreatic amylase or lipase after administration of liquid meal tests, according to the results of a recently published research letter.

Pancreatic amylase and lipase plasma, two enzymes produced by the pancreas to help digest food, are also associated with pancreatic inflammation and pancreatitis. According to David P. Sonne, of the Center for Diabetes Research, University of Copenhagen, Denmark, and colleagues, several recent studies of incretin-based therapies have shown increases in the concentrations of amylase and lipase in patients assigned these therapies.

The example they cited was from the SCALE Maintenance study, which looked at high-dose liraglutide for weight loss maintenance in obese or overweight patients without diabetes who lost weight through a low-calorie diet. Results of the study showed that median lipase concentration was increased throughout the study period.

According to the researchers, “it has been speculated that elevated GLP-1 receptor agonist concentrations may be the direct cause” of the increase in amylase and lipase concentrations in these patients. However, they added that “it has never been shown whether plasma concentrations of pancreas-specific amylase or lipase exhibit postprandial changes, which could arise from endogenous GLP-1 reaching the pancreatic acini.”

To explore this association further, Sonne and colleagues conducted a study that included 15 patients with type 2 diabetes and measured pancreas-specific amylase and lipase in the blood after they ingested oral glucose and three isocaloric and isovelmic liquid meals. These results were then compared against a group of control patients.

They found that both amylase and lipase concentrations were within normal range for patients with diabetes and control patients. Control patients had slightly increased concentrations of amylase compared with patients with type 2 diabetes (P<0.05), but levels of lipase were similar between the two groups.

Neither amylase nor lipase were increased after the liquid meal tests, “suggesting that postprandial elevations of endogenous GLP-1 (two- to threefold) cannot trigger enzyme release from the human pancreas, at least not acutely.”

“These results suggest that the observation of elevated plasma amylase and lipase concentrations in patients treated with GLP-1 receptor agonists is unlikely to reflect potentiation or prolongation of an endogenous GLP-1 effect but rather indicates that pharmacologic effects of GLP-1 receptor agonists on pancreatic acini could be the cause,” the researchers wrote. “However, as the current study reflects acute experimental administration of 500 kcal liquid meals, it remains unknown if larger and/or solid meals may induce different effects, especially if accompanied with alcohol intake.”

Reference: Sonne DP, et al. Pancreatic amylase and lipase plasma concentrations are unaffected by increments in endogenous GLP-1 levels following liquid meal tests. Diabetes Care. 2015;38:e71-e72.