Certified Diabetes Educator Practice Exam

Biguanides, primarily represented by the drug metformin, function mainly by decreasing hepatic glucose production. This means that they work directly on the liver to reduce the amount of glucose that is produced and released into the bloodstream. By decreasing hepatic glucose output, biguanides lead to a lowering of blood glucose levels, which is particularly beneficial for individuals with type 2 diabetes who often experience elevated fasting blood glucose levels due to increased glucose production from the liver.

Additionally, biguanides are known to enhance insulin sensitivity in peripheral tissues, but this enhancement is secondary to their primary action of reducing glucose output from the liver. The other mechanisms, such as increasing insulin secretion or enhancing beta-cell function, do not apply to biguanides; these actions are more characteristic of other classes of diabetes medications. Similarly, the inhibition of glucose absorption in the intestines is primarily associated with other medications, such as alpha-glucosidase inhibitors. Thus, the primary and defining feature of biguanides is their ability to decrease hepatic glucose production, which plays a crucial role in managing blood glucose levels in patients with type 2 diabetes.