By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

What are Triglycerides?

When you eat a fatty meal, much of the fat is absorbed directly into the bloodstream as triglycerides (which is simply the technical name for fat), and it may come as no surprise to learn that having a high triglyceride level in the blood is a risk factor for coronary heart disease. Nevertheless, of the three major lipid components (the other two being LDL- and HDL-cholesterol) the triglycerides are the least important. The problem in evaluating the role of triglycerides has been that there is a strong association between triglycerides and HDL, such that high triglycerides tend to occur in conjunction with a low HDL, so that it's not clear whether the increased risk is due to the low HDL rather than the high triglycerides. Nevertheless, in the Framingham Heart Study a high triglyceride level in women over the age of 50 does appear to be an independent risk factor.

Triglycerides may be high for a number of reasons, the most important of which are listed below:

Causes of High Blood Triglycerides

Genetic

High fat intake

Obesity

Diabetes

Alcohol

There are a number of genetic conditions which lead to increased triglycerides; they may also be associated with high cholesterol, low HDL, and high blood pressure. The combination of obesity, high triglycerides, and insulin resistance is common, and often referred to as the insulin resistance syndrome. In some people, even moderate alcohol intake can raise triglycerides. One of the side effects of some blood pressure-lowering medications is to raise triglycerides, which is most noticeable with the diuretics, although the changes are usually quite small.

Because the blood triglyceride level is affected by food, it's important to have your blood tested after you've fasted for at least 12 hours (cholesterol and HDL are less affected).

The treatment of high triglycerides is primarily by diet, and is generally no different from the treatment of high cholesterol--restriction of calorie and fat intake, except that if alcohol is thought to be contributory, it should be restricted as well. The drug fenofibrate is especially effective at lowering triglycerides, and in women, transdermal estrogens can be used.