Certified Diabetes Educator Practice Exam 2026 - Free Practice Questions and Study Resource.

Insulin plays a critical role in glucose metabolism, primarily by lowering blood glucose levels. One of its key actions is to inhibit glucagon release from the alpha cells of the pancreas. Glucagon is a hormone that raises blood glucose levels by promoting the hepatic production of glucose through gluconeogenesis and glycogenolysis. When insulin is secreted in response to rising blood glucose levels, such as after a meal, it acts to counterbalance glucagon's effects. This inhibition of glucagon release is essential in maintaining blood glucose homeostasis; by preventing glucagon from stimulating gluconeogenesis and glycogenolysis, insulin helps ensure that blood sugar levels do not rise excessively.

In situations where insulin levels are low, such as fasting or prolonged periods without food, glucagon secretion increases, leading to elevated blood glucose levels. This interplay between insulin and glucagon is vital for the body's overall glucose regulation. Therefore, the correct choice highlights the important regulatory role that insulin plays in suppressing glucagon secretion, contributing to the delicate balance of glucose homeostasis.