The question asks which drug acts as a PPAR-alpha agonist. Among these four diabetes drugs, only one interacts with PPAR receptors at all.
- Sulfonylurea: Stimulates insulin release by blocking potassium channels on beta cells, unrelated to PPAR signaling.
- Metformin: Cuts liver glucose production and activates AMPK, again bypassing PPAR receptors entirely.
- Acarbose: Slows carbohydrate breakdown in the intestine by blocking digestive enzymes, a local gut effect with no PPAR link.
- Pioglitazone: A thiazolidinedione that primarily activates PPAR-gamma to improve insulin sensitivity, but it also carries meaningful PPAR-alpha agonist activity, which contributes to its favorable effect on lipid levels alongside its glucose-lowering action.
Pioglitazone is the only option among the four that engages PPAR-alpha in any capacity.
So the correct answer is Pioglitazone.