Non-high density lipoprotein cholesterol may be a valuable independent predictor for adverse cardiac events in patients with heart disease, according to a report in the October 22nd issue of Circulation.

Previous studies have shown that the general category of non-high density lipoprotein cholesterol is a strong predictor of adverse events in people who have not yet developed clinical evidence of heart disease. As a result, the latest version of the National Cholesterol Education Program guidelines recommends that doctors first target low-density cholesterol, but that they also pay attention to non-high density lipoprotein cholesterol.

“Low-density lipoprotein cholesterol, even though it is a ‘bad’ cholesterol, tells only part of the story,” says lead author Vera Bittner, M.D., M.S.P.H. “We found that while low-density lipoprotein cholesterol is important, the non-high density lipoprotein cholesterol is the more important predictor ? at least in this group of people with heart disease.”

In the current study, American researchers studied data compiled previously during the Bypass Angioplasty Revascularization Investigation trial, a study that followed 1,514 heart patients (73 percent male, average age 61 years) for five years, with measurement of their cholesterol levels throughout the study period and continuing monitoring of their cardiovascular health.

The study authors found that non-high density lipoprotein cholesterol is a strong and independent predictor of non-fatal myocardial infarction and angina at five years, even after adjustment for other risk factors such as age and smoking --- a stronger predictor than total cholesterol, low-density lipoprotein cholesterol, triglycerides, and high-density lipoprotein cholesterol

There was a 4.9 percent increase in risk of myocardial infarction for every 10 milligram per deciliter (mg/dL) increase in non-high density lipoprotein cholesterol compared with a 4.3 percent increase in risk for every 10 mg/dL of total cholesterol and a 1.6 percent increase in risk with each 10 mg/dL of triglycerides. The increased risk associated with increased low-density lipoprotein cholesterol levels was not significant. The researchers also found that non-high density lipoprotein cholesterol had the most profound effect on angina, with a 4.9 percent increased risk for every 10mg/dL increase in level.
Bittner noted that one possible reason for the insignificance of low-density lipoprotein cholesterol levels is that many of the study patients were already on medications to lower low-density lipoprotein levels.

“What we have done is purely focused on the low-density lipoprotein cholesterol and ignored these other particles. This study tells the consumer and physician to look at the entire picture and treat both,” she said.
Medications that have traditionally been used to lower low-density lipoprotein cholesterol, such as statins, tend to affect other lipoproteins only in part, according to Bittner. Niacin and some other medications might better treat these particles, which have higher triglyceride content. Often patients require a combination of medications for the best results.

In an accompanying editorial, Scott M. Grundy, M.D., Ph.D., agreed that non-high density lipoprotein cholesterol is an important part of the treatment picture. However, he suggested it should be a secondary target of therapy until more evidence shows that it is more important than low-density lipoprotein cholesterol.

“I think the study shows that non-high density lipoprotein cholesterol increasingly appears to be a useful predictor of coronary outcomes, and the findings of this study support the National Cholesterol Education Program’s new emphasis of non-high density lipoprotein cholesterol as a secondary target of treatment after low-density lipoprotein cholesterol,” Grundy said.