GLP-1 receptor agonists (GLP-1 RAs) with exenatide b.i.d. first approved to treat type 2 diabetes in 2005 have been further developed to yield effective compounds/preparations that have overcome the original problem of rapid elimination (short half-life), initially necessitating short intervals between injections (twice daily for exenatide b.i.d.). To summarize current knowledge about GLP-1 receptor agonist. At present, GLP-1 RAs are injected twice daily (exenatide b.i.d.), once daily (lixisenatide and liraglutide), or once weekly (exenatide once weekly, dulaglutide, albiglutide, and semaglutide). A daily oral preparation of semaglutide, which has demonstrated clinical effectiveness close to the once-weekly subcutaneous preparation, was recently approved. All GLP-1 RAs share common mechanisms of action: augmentation of hyperglycemia-induced insulin secretion, suppression of glucagon secretion at hyper- or euglycemia, deceleration of gastric emptying preventing large post-meal glycemic increments, and a reduction in calorie intake and body weight. Short-acting agents (exenatide b.i.d., lixisenatide) have reduced effectiveness on overnight and fasting plasma glucose, but maintain their effect on gastric emptying during long-term treatment. Long-acting GLP-1 RAs (liraglutide, once-weekly exenatide, dulaglutide, albiglutide, and semaglutide) have more profound effects on overnight and fasting plasma glucose and HbA1c, both on a background of oral glucose-lowering agents and in combination with basal insulin. Effects on gastric emptying decrease over time (tachyphylaxis). Given a similar, if not superior, effectiveness for HbA1c reduction with additional weight reduction and no intrinsic risk of hypoglycemic episodes, GLP-1RAs are recommended as the preferred first injectable glucose-lowering therapy for type 2 diabetes, even before insulin treatment. However, GLP-1 RAs can be combined with (basal) insulin in either free- or fixed-dose preparations. More recently developed agents, in particular semaglutide, are characterized by greater efficacy with respect to lowering plasma glucose as well as body weight. Since 2016, several cardiovascular (CV) outcome studies have shown that GLP-1 RAs can effectively prevent CV events such as acute myocardial infarction or stroke and associated mortality. Therefore, guidelines particularly recommend treatment with GLP-1 RAs in patients with pre-existing atherosclerotic vascular disease (for example, previous CV events). The evidence of similar effects in lower-risk subjects is not quite as strong. Since sodium/glucose cotransporter-2 (SGLT-2) inhibitor treatment reduces CV events as well (with the effect mainly driven by a reduction in heart failure complications), the individual risk of ischemic or heart failure complications should guide the choice of treatment. GLP-1 RAs may also help prevent renal complications of type 2 diabetes. Other active research areas in the field of GLP-1 RAs are the definition of subgroups within the type 2 diabetes population who particularly benefit from treatment with GLP-1 RAs. These include pharmacogenomic approaches and the characterization of non-responders. Novel indications for GLP-1 RAs outside type 2 diabetes, such as type 1 diabetes, neurodegenerative diseases, and psoriasis, are being explored. Thus, within 15 years of their initial introduction, GLP-1 RAs have become a well-established class of glucose-lowering agents that has the potential for further development and growing impact for treating type 2 diabetes and potentially other diseases.

Context: Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are established therapeutics for type 2 diabetes and obesity. Among other mechanisms, they slow gastric emptying and motility of the small intestine. This helps to limit postprandial glycemic excursions and reduce chylomicron formation and triglyceride absorption. Conversely, motility effects may have detrimental consequences, eg, retained gastric contents at endoscopy or general anesthesia, potentially complicated by pulmonary aspiration or bowel obstruction. Data Acquisition: We searched the PubMed database for studies involving GLP-1RA therapy and adverse gastrointestinal/biliary events. Data Synthesis: Retained gastric contents at the time of upper gastrointestinal endoscopy are found more frequently with GLP-1 RAs but rarely are associated with pulmonary aspiration. Well-justified recommendations for the periprocedural management of GLP-1RAs (eg, whether to withhold these medications and for how long) are compromised by limited evidence. Important aspects to be considered are (1) their long half-lives, (2) the capacity of GLP-1 receptor agonism to slow gastric emptying even at physiological GLP-1 concentrations, (c) tachyphylaxis observed with prolonged treatment, and (d) the limited effect on gastric emptying in individuals with slow gastric emptying before initiating treatment. Little information is available on the influence of diabetes mellitus itself (ie, in the absence of GLP-1 RA treatment) on retained gastric contents and pulmonary aspiration. Conclusion: Prolonged fasting periods regarding solid meal components, point-of-care ultrasound examination for retained gastric content, and the use of prokinetic medications like erythromycin may prove helpful and represent an important area needing further study to increase patient safety for those treated with GLP-1 RAs.

OBJECTIVE Short-acting glucagon-like peptide 1 receptor agonists (GLP-1 RAs) decelerate gastric emptying more than long-acting GLP-1 RAs. Delayed gastric emptying is a risk factor for gastroesophageal reflux disease. We aimed to measure esophageal reflux and function as well as gastric emptying and acid secretion during treatment with short-acting (lixisenatide) and long-acting (liraglutide) GLP-1 RAs. RESEARCH DESIGN AND METHODS A total of 57 subjects with type 2 diabetes were randomized to a 10-week treatment with lixisenatide or liraglutide. Changes from baseline in the number of reflux episodes during 24-h pH registration in the lower esophagus, lower esophagus sphincter pressure, gastric emptying (¹³C-sodium octanoate acid breath test), and gastric acid secretion (¹³C-calcium carbonate breath test) were analyzed. RESULTS Gastric emptying half-time was delayed by 52 min (Δ 95% CI 16, 88) with lixisenatide (P = 0.0065) and by 25 min (3, 46) with liraglutide (P = 0.025). There was no difference in the number of reflux episodes (mean ± SEM 33.7 ± 4.1 vs. 40.1 ± 5.3 for lixisenatide and liraglutide, respectively, P = 0.17) or the extent of gastroesophageal reflux (DeMeester score) (35.1 ± 6.7 vs. 39.7 ± 7.5, P = 0.61), with similar results for the individual GLP-1 RAs. No significant changes from baseline in other parameters of esophageal motility and lower esophageal sphincter function were observed. Gastric acidity decreased significantly by −20.7% (−40.6, −0.8) (P = 0.042) with the GLP-1 RAs. CONCLUSIONS Lixisenatide exerted a more pronounced influence on gastric emptying after breakfast than liraglutide. Neither lixisenatide nor liraglutide had significant effects on esophageal reflux or motility. Gastric acid secretion appears to be slightly reduced by GLP-1 RAs.

Aim: To clarify the distinct effects of a long‐acting (liraglutide) and a short‐acting (lixisenatide) glucagon‐like peptide‐1 receptor agonist (GLP‐1 RA) on macronutrient intake, gastrointestinal side effects and pancreas function. Materials and Methods: Fifty participants were randomized to either lixisenatide or liraglutide for a treatment period of 10 weeks. Appetite, satiety, macronutrient intake, gastrointestinal symptoms and variables related to pancreatic function and gastric emptying were assessed at baseline and after treatment. Results: Both GLP‐1 RAs reduced macronutrient intake similarly. Weight loss and appetite reduction were not related to the delay in gastric emptying or gastrointestinal side effects ( P > .05). Lipase increased significantly with liraglutide treatment (by 18.3 ± 4.1 U/L; P = .0001), but not with lixisenatide (−1.8 ± 2.4 U/L; P = .46). Faecal elastase and serum ß‐carotin levels (indicators for exocrine pancreas function) improved in both groups ( P < .05). Changes in lipase activities did not correlate with gastrointestinal symptoms ( P > .05 for each variable). Conclusions: 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 a result of treatment with short‐ or long‐acting GLP‐1 RAs are not driven by changes in gastric emptying or gastrointestinal side effects.

Hidradenitis suppurativa (HS) is a chronic skin disease that is often associated with metabolic disorders. Diabetes mellitus (DM) is a frequent comorbidity in HS. There is currently no established screening for DM in HS patients. The aim of our study was to identify high-risk groups of HS patients that develop DM and to assess the frequency of different types of DM present in HS patients. To do so, we conducted a monocentric study in 99 patients with HS. All patients underwent detailed clinical and laboratory assessments, including the determination of glycated hemoglobin. Among the 20.2% of patients that presented with DM, type 2 was by far the most prevalent (19 out of 20 patients). Moreover, male gender, age, BMI, Hurley stage, modified Hidradenitis Suppurativa Score (mHSS), DLQI and hypertension all correlated with the glycated hemoglobin levels in the HS patients. In the multivariable analysis, Hurley stage III, older age, and higher BMI were significantly associated with DM. Specifically, patients at Hurley stage III were at a 5.3-fold increased risk of having DM type II compared to patients at earlier Hurley stages. Since many of the HS patients had not been diagnosed, our study reveals shortcomings in the screening for DM and suggest that this should be routinely performed in HS patients at high risk to avoid secondary complications.