Triglycerides and HDL Cholesterol

Diabetes carries a high risk of atherosclerosis, and cardiovascular disease, especially coronary heart disease (CHD) and stroke, is by far the leading cause of death among patients with type 2 diabetes. Although statins reduce the risk of major vascular events by about one-fifth per millimole per liter reduction in LDL cholesterol, with similar proportional reductions in major coronary events, stroke, and the need for coronary revascularization, the residual risk remains high. In the Scandinavian Simvastatin Survival Study (4S) (1), although the relative risk reduction in diabetic patients was larger than in nondiabetic patients, simvastatin-treated diabetic patients were still at higher risk of death than the placebo-treated nondiabetic patients. Multifactorial intervention reduces the risk even further, but significant danger remains. Current guidelines call for an aggressive treatment strategy to reduce LDL cholesterol, blood pressure, and glucose levels in diabetic patients, but data concerning the management of high triglyceride (TG) levels and low HDL cholesterol levels remains inconclusive. This article reviews the data concerning diabetic dyslipidemia and its management. The cluster of lipid abnormalities associated with type 2 diabetes is defined by a high concentration of TG and small dense LDL and a low concentration of HDL cholesterol. Plasma LDL cholesterol levels are generally normal. Insulin resistance is believed to contribute to this atherogenic dyslipidemia by increasing the hepatic secretion of VLDL and other apolipoprotein (apo)B-containing lipoprotein particles, as a result of increased free fatty acid flux to the liver (2,3). This may also be the result of a diminished suppressive effect of insulin on apoB secretion, either at the level of the regulation of apoB degradation, or inhibition of microsomal TG transfer protein activity (4). Through the action of cholesterol ester transfer protein, TGs are transferred from VLDL to HDL, creating TG-rich HDL particles, which are hydrolyzed by hepatic …