American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the primary function of GLP-1 receptor agonists in diabetes management?

1. To reduce blood sugar levels directly

2. To enhance incretin action

3. To stimulate glucagon release

4. To increase body weight

The correct answer is: To enhance incretin action

GLP-1 receptor agonists play a crucial role in the management of diabetes primarily through their ability to enhance incretin action. Incretins are hormones released from the intestines in response to food intake, and they increase insulin secretion from the pancreas while inhibiting glucagon secretion. This results in lower blood glucose levels after meals. By mimicking the action of glucagon-like peptide-1 (GLP-1), these agonists improve glucose-dependent insulin secretion, meaning they stimulate the pancreas to release insulin in response to high blood sugar levels, particularly after eating. They also slow gastric emptying, which contributes to a feeling of fullness and reduces postprandial blood glucose spikes. The other options, while related to factors influencing diabetes, do not encapsulate the primary function of GLP-1 receptor agonists. For instance, while these drugs can lead to some reduction in blood sugar levels indirectly due to their incretin effect, they don't directly lower blood sugar like traditional insulin therapies. They also do not stimulate glucagon release; instead, they work to reduce it. Furthermore, while GLP-1 receptor agonists can lead to weight loss in many patients, weight gain is not a primary function of these medications and is often a