Macronutrient intake, appetite, food preferences and exocrin
GLP-1 receptor agonists (GLP-1 RAs) promote weight loss, but also gastrointestinal side-effects. The extent of these side-effects may depend on dosing and pharmacokinetic attributes. However, it remains controversial whether GLP-1 RAs differentially affect digestive and pancreatic function and whether gastrointestinal side-effects are correlated with gastric emptying or the pharmacokinetic characteristics of specific GLP-1 RAs. The present study aims to clarify the distinct effects of a long- (liraglutide) and a short-acting (lixisenatide) GLP-1 RA on macronutrient intake, gastrointestinal side-effects, and pancreas function.

50 participants were randomized to either lixisenatide or liraglutide for a treatment period of 10?weeks. Appetite, satiety, macronutrient intake, gastrointestinal symptoms and parameters related to pancreatic function and gastric emptying were assessed at baseline and after treatment.

-- Both GLP-1 RAs reduced macronutrient intake similarly. Weight loss or appetite reduction were not related to the delay of gastric emptying or gastrointestinal side-effects.

-- Lipase increased significantly with liraglutide treatment (by 18.3 ±4.1 U/l) but not with lixisenatide (-1.8 ±2.4 U/l).

-- Faecal elastase and serum Beta-carotin levels (indicators for exocrine pancreas function) improved in both groups.

-- Changes in lipase activities did not correlate with gastrointestinal symptoms.

Conclusively, both GLP-1 RAs comparably affected body weight, energy, and macronutrient intake. Both treatments were associated with indicators of improved exocrine pancreas function. Reductions in appetite and body weight as the result of treatment with short- or long-acting GLP-1 RAs are not driven by changes in gastric emptying or gastrointestinal side-effects.