March 23 (HealthDay News) -- Many Americans have higher-than-recommended levels of the blood fats called triglycerides, and most aren't making the lifestyle changes necessary to bring those levels down, a study finds.
"Clearly, the focus in this country has been on cholesterol levels," said Dr. Earl S. Ford, with the U.S. Centers for Disease Control and Prevention and lead author of a report in the March 23 Archives of Internal Medicine. "But there are a fair number of studies that suggest that triglycerides have a role in cardiovascular disease."
While just about everyone knows about the link between cholesterol and heart disease, few Americans seem concerned about triglycerides, which are the most common kind of fats in the body -- and in food.
Triglyceride levels aren't nearly as big a concern as cholesterol levels. While the journal report states that, "increasing evidence supports triglyceride concentration as a risk factor for cardiovascular disease," the report also hedges that a bit, saying, "if triglycerides are indeed a risk factor."
Nonetheless, the National Cholesterol Education Program offers a list of recommendations about blood triglyceride levels: that they are best kept under 150 milligrams per deciliter; considered borderline high between 150 and 199 milligrams per deciliter; and deemed high at 200 or greater.
Data on 5,610 Americans in National Health and Nutrition Examination Surveys between 1999 and 2004 found that 33.1 percent of them had borderline high triglyceride levels; 17.9 percent had readings of 200 or higher; 1.7 percent came in at 500 or higher; and 0.4 percent were at 1,000 or higher, the study found.
Use of three triglyceride-lowering drugs was limited, with 2.6 percent of those in the borderline high group and 3.6 percent of those in the 200-and-higher group taking them. The drugs -- gembifrozil, niacin and fenofibrate --are also prescribed to raise levels of HDL cholesterol, the "good" kind that helps prevent artery blockage.
That may be just as well, Ford said. "Unlike LDL cholesterol, where we have all kinds of trials showing the benefits of statins against cardiovascular disease, there is not as strong a database for triglycerides," he said. "Until we get stronger evidence of benefit, drug treatment of triglycerides remains a little uncertain. Whether taking these drugs will reduce cardiovascular disease is unclear."
So the recommended treatment for elevated triglyceride levels is the kind of lifestyle recommended for high cholesterol levels, Ford said. Indeed, survey participants with high triglyceride levels tended to be overweight, inactive and smoke.
Losing weight, getting exercise, eating low-fat foods and giving up smoking apply to triglycerides as well, Ford said. An additional recommendation is to reduce consumption of alcohol, which promotes triglyceride production by the liver.
Dr. Stephen Nicholls, a cardiologist at the Cleveland Clinic, believes that triglycerides may deserve more scrutiny by physicians. "Many doctors are not sure about how aggressive they should be in treating elevated triglycerides," he said. "There are always other issues, such as obesity and smoking, involved. But we are understanding more and more that looking after triglycerides is important in providing heart care. If you look at large populations, those with high levels of triglycerides always do worse."
SOURCES: Earl S. Ford, M.D., MPH, medical officer, U.S. Public Health Service, Atlanta; Stephen Nicholls M.D., Ph.D, cardiologist, Cleveland Clinic; March 23, 2009, Archives of Internal Medicine