Question

Which oral hypoglycemic agent increases the levels of incretin hormone by inhibiting the enzyme dipeptidyl peptidase-4 (DPP-4):

• A. Metformin
• B. Pioglitazone
• C. Sitagliptin
• D. Glipizide

Answer 1

The Correct Option is C

The correct option is (C): Sitagliptin.

Answer 2

The question asks which oral hypoglycemic drug works by inhibiting the enzyme dipeptidyl peptidase-4 (DPP-4), which raises the level of incretin hormones. Let's check each option.

1. Metformin: Metformin lowers blood glucose mainly by reducing glucose production in the liver and improving insulin sensitivity in tissues. It does not act on the DPP-4 enzyme.
2. Pioglitazone: Pioglitazone is a thiazolidinedione that activates the PPAR-gamma receptor, improving insulin sensitivity in fat and muscle tissue. This mechanism has nothing to do with DPP-4.
3. Sitagliptin: Sitagliptin blocks the DPP-4 enzyme, which normally breaks down incretin hormones like GLP-1 soon after they are released. With DPP-4 blocked, GLP-1 stays active longer in the blood, boosting glucose-dependent insulin release and lowering glucagon, which together bring blood sugar down.
4. Glipizide: Glipizide is a sulfonylurea that stimulates insulin release directly from pancreatic beta cells by closing potassium channels on their membrane. It does not touch the DPP-4 enzyme or incretin hormone levels in this way.

Only sitagliptin works through DPP-4 inhibition to raise incretin hormone activity, matching exactly what the question describes.

So the correct answer is Sitagliptin.