Though the majority of people with problem cholesterol have high LDL cholesterol, there are some people whose lipid levels show other abnormalities. The most common of these disorders are elevated blood triglyceride levels or reduced HDL values, both of which can occur with or without high LDL.

Low levels of HDL or higher than normal levels of triglyceride increase the likelihood of developing coronary disease, and so they are important to address. They can both be diagnosed by a fasting lipid profile test, and each problem requires a slightly different treatment plan.

If you have high triglyceride levels but normal levels of HDL and LDL, one of two things can be to blame: a genetic abnormality or unhealthy lifestyle choices. More commonly, it’s the latter. Normal triglyceride levels are less than 150. Levels of 200–1,000 can be caused by having uncontrolled diabetes, being significantly overweight, drinking too much alcohol, or taking certain medications.

Medications that affect triglyceride levels include estrogen (either in hormonal replacement regimens or as part of an oral contraceptive), isotretinoin, beta-blockers, thiazide diuretics, and medications that combat HIV. People with genetic abnormalities that cause their bodies to be unable to metabolize chylomicrons can have triglyceride levels in the thousands.

Chylomicrons are 90 percent to 95 percent triglyceride by weight, and they normally get cleared from the bloodstream about twelve hours after eating. If your body can’t clear them, triglyceride levels soar. How dangerous are these high levels? It depends.

The extraordinarily high triglyceride levels caused by several of the genetic abnormalities generally do not cause heart disease because it seems that the chylomicron is not prone to producing inflammation in the artery wall, the first step in causing a heart attack.

However, it’s hard to be confident that heart disease risk for people with triglyceride levels in the thousands is definitely low, because there are relatively few of these people to study and the metabolism of the chylomicron leads to a remnant particle that may cause heart disease.

In any case, very high triglyceride levels can cause other major health problems in the liver and pancreas, so physicians will aggressively treat these patients to lower their triglycerides. In this case, treatment would include a very low-fat diet where only 5 percent to 6 percent of calories come from fat, as opposed to the 20 percent to 30 percent we generally recommend.

These individuals also get some benefit from taking fibrate medications, but the effect of the medicines is easily overwhelmed by poor dietary choices. People with high triglyceride levels caused by lifestyle factors, typically under 1,000 mg/dL, on the other hand, do have an increased risk for heart disease.

For women, this increase in risk may be two to two and a half times greater than in women with normal levels, whereas for men the risk appears to be less, about one and a half times. In these cases, the obvious first step is to change the problematic lifestyle.

Work with your doctor to treat your diabetes better, switch to a medication that doesn’t affect triglyceride levels, stop drinking, eat healthier, and exercise. Besides contributing to weight loss, exercise also lowers triglycerides because your muscles use triglycerides as fuel. If you don’t have any of these lifestyle risks or your triglyceride levels don’t fall even after you modify your lifestyle, your doctor will probably put you on fibrates.