Do high triglyceride levels cause atherosclerosis?

Whether elevated triglyceride levels in the blood lead to atherosclerosis and heart attacks is controversial. While most doctors now believe that an abnormally high triglyceride level is a risk factor for atherosclerosis, it is difficult to conclusively prove that elevated triglyceride by itself can cause atherosclerosis. However, it is increasingly recognized that elevated triglyceride is often associated with other conditions that increase the risk of atherosclerosis, including obesity, low levels of HDL- cholesterol, insulin resistance and poorly controlled diabetes mellitus, and small, dense LDL cholesterol particles.

What are the causes of elevated triglyceride levels?

In some people, abnormally high triglyceride levels (hypertriglyceridemia) are inherited. Examples of inherited hypertriglyceridemia disorders include mixed hypertriglyceridemia, familial hypertriglyceridemia, and familial dysbetalipoproteinemia.
Hypertriglyceridemia can often be caused by non-genetic factors such as obesity, excessive alcohol intake, diabetes mellitus, kidney disease, and estrogen- containing medications such as birth control pills.

How can elevated blood triglyceride levels be treated?

The first step in treating hypertriglyceridemia is a low fat diet with a limited amount of sweets, regular aerobic exercise, loss of excess weight, reduction of alcohol consumption, and stopping cigarette smoking. In patients with diabetes mellitus, meticulous control of elevated blood glucose is also important.

When medications are necessary, fibrates (such as Lopid), nicotinic acid, and statin medications can be used. Lopid not only decreases triglyceride levels but also increases HDL cholesterol levels and LDL cholesterol particle size. Nicotinic acid lowers triglyceride levels, increases HDL cholesterol levels and the size of LDL cholesterol particles, as well as lowers the levels of Lp (a) cholesterol.

The statin drugs have been found effective in decreasing triglyceride as well as LDL cholesterol levels and, to a lesser extent, in elevating HDL cholesterol levels. A relatively new medicine, fenofibrate (Tricor), shows promise as an effective agent in lowering serum triglyceride levels as well as raising HDL levels, particularly in patients who have had suboptimal responses to Lopid. In some patients, a combination of Lopid or Tricor with adjunctive statin therapy (see below) may be prescribed. While this combination is often effective in patients with complex lipid disorders, the potential for side effects may be increased and such patients should be under strict medical supervision.