Biguanides primarily function by which of the following mechanisms?

• A. Increasing insulin sensitivity
• B. Increasing insulin secretion
• C. Decreasing gluconeogenesis and glucose absorption
• D. Decreasing cholesterol synthesis

Answer: (C)

Biguanides, such as metformin, primarily function by decreasing gluconeogenesis and glucose absorption. Gluconeogenesis is the process through which glucose is produced in the liver from non-carbohydrate sources. By inhibiting this pathway, biguanides effectively lower the amount of glucose that is released into the bloodstream, which is especially beneficial for individuals with type 2 diabetes whose livers are producing excessive glucose. Additionally, biguanides also promote a modest reduction in intestinal absorption of glucose, further supporting blood sugar control.

This mechanism addresses the underlying insulin resistance that characterizes type 2 diabetes. While they do not primarily work by increasing insulin secretion or directly altering cholesterol synthesis, their primary action of reducing gluconeogenesis and decreasing glucose absorption plays a crucial role in managing blood glucose levels and improving the overall metabolic profile of patients with insulin resistance.