How do fibrates lower triglyceride levels?

Fibrates are a class of lipid-lowering agents that primarily lower triglyceride levels by increasing lipolysis of triglyceride-rich lipoproteins. They activate peroxisome proliferator-activated receptors (PPARs), specifically PPAR-alpha, which leads to increased expression of genes that promote the breakdown of triglycerides. This process enhances the activity of lipoprotein lipase, an enzyme that hydrolyzes triglycerides in the bloodstream, facilitating their conversion into free fatty acids. By promoting this lipolytic process, fibrates effectively reduce the levels of triglycerides in the blood, which is particularly beneficial for patients with hypertriglyceridemia.

The other options do not align with the mechanism of action of fibrates. For instance, increasing hepatic glucose production is not related to the triglyceride-lowering effect of fibrates. The option concerning blocking absorptive pathways in the intestine pertains more to the mechanism of action for other lipid-lowering agents like cholesterol absorption inhibitors. Similarly, enhancing HDL cholesterol synthesis is a function of some lipid-lowering agents, but it does not directly relate to the primary action of fibrates in lowering triglyceride levels.