How do GLP-1 receptor agonists improve glucose control beyond insulin secretion?

• A. They Inhibit Glucagon Release Only
• B. They Enhance Glucose-Dependent Insulin Secretion, Suppress Glucagon, Slow Gastric Emptying, and Promote Weight Loss
• C. They Have No Effect on Gastric Emptying
• D. They Increase Insulin Secretion Independent of Glucose

Answer: (B)

GLP-1 receptor agonists improve glucose control by acting on several pathways beyond simply boosting insulin. First, they stimulate insulin release in a glucose-dependent way, meaning more insulin is released when blood glucose is high and less when it’s normal, which helps lower postprandial glucose with a lower risk of hypoglycemia. Second, they suppress glucagon secretion when glucose is elevated, reducing hepatic glucose production and helping blunt the rise in blood glucose after meals. Third, they slow gastric emptying, so nutrients enter the bloodstream more gradually and glucose spikes after eating are dampened. Fourth, they promote weight loss by reducing appetite and caloric intake, which further improves insulin sensitivity and long-term glycemic control. The other statements are incomplete: focusing only on inhibiting glucagon misses the insulinotropic, weight-loss, and gastric-emptying effects; denying any effect on gastric emptying ignores a major postprandial control mechanism; and claiming insulin secretion independent of glucose contradicts the glucose-dependent nature of GLP-1–mediated insulin release.