This disclosure provides a novel role for microRNA (miR) regulation of lipid metabolism via the MTP pathway, leading to reductions in apoB secretion and blood lipid levels. MiR regulation of the MTP pathway is shown herein to reduce hyperlipidemia and atherosclerosis in vivo. Therefore, inhibition of MTP expression and activity by miR regulation is identified as a new therapeutic target for treatment of cardiovascular disease and conditions or diseases associated with cardiovascular disease such as hyperlipidemia, atherosclerosis, and metabolic syndrome. Treatment of cardiovascular disease and associated conditions or diseases with the novel MTP inhibitors of the invention, such as miR-30c homologs or miR-30c agonists, reduces MTP-associated lipid production without side effects that occur with other methods of MTP inhibition.