Bad Cholesterol Levels Among American Adults Decreasing

Cholesterol is a waxy substance found in all parts of the body. It helps protect nerves, make cell tissues, and produce certain hormones. But when there is too much cholesterol in the blood, the excess builds up on the walls of the arteries, causing them to narrow and harden. Large deposits of cholesterol can completely block an artery. If an artery that supplies blood to the muscles of the heart becomes blocked, a heart attack can occur. If an artery that supplies blood to your brain becomes blocked, a stroke can occur. In fact, cholesterol buildup is the most common cause of heart disease, and it happens so gradually that you aren’t even aware of it. The higher your blood cholesterol, the greater your chance of this buildup—and the greater your chance of heart attack or stroke.

Almost everyone can benefit from lowering their blood cholesterol, and according to a new study published in the November 18 issue of the Journal of the American Medical Association, many Americans have had success in doing so. Researchers say that an analysis of data from the National Health and Nutrition Examination Survey (NHANES), a program of studies designed to access the health and nutrition of large numbers of people in the U.S., shows that overall, the prevalence for high LDL “bad” cholesterol decreased from 31.5 percent in 1999-2000 to 21.2 percent in 2005-2006. During the same time, statin use rose from 8 percent to 13.4 percent.The study’s lead researcher, Dr. Elena V. Kuklina, said the drop in high LDL rates may be a result of more people eating a better diet, getting more exercise, and taking cholesterol-lowering medication.

However, among those who tested high for LDL, nearly 36 percent had not been screened for LDL in the past, almost 25 percent who had been screened previously were unaware they had high LDL levels, and more than 39 percent were untreated or inadequately treated in 2005-2006, findings that suggest there are still a large percentage of adults who are likely unaware they have high cholesterol. “We found 60 percent of people with high levels of LDL cholesterol didn’t know about these conditions,” Dr. Kuklina said. “They are in two major groups—those who have never been screened, and those who have been screened but not diagnosed.”

The researchers say that while the prevalence for high LDL levels decreased more than 10 percent overall, it varied significantly by patient risk category. The greatest prevalence occurred in those who were considered high risk, which included people with self-reported heart disease, angina, heart attack, stroke and diabetes, as well as others with high blood glucose levels while fasting. In that category, high LDL levels declined from 69 percent in 1999-2000 to 59 percent in 2005-2006, the study showed.

Among all risk groups, screening rates for high cholesterol didn’t change significantly, remaining at less than 70 percent during the study periods—far below the 80 percent target set by Healthy People 2010, the nation’s health objectives. In an editorial accompanying the study, Drs.Thomas A. and J. Michael Gaziano of Brigham and Women’s Hospital in Boston called the 70 percent screening rate “disappointing,” placing the blame on the complexity of guidelines that doctors use to determine when and if patients should be checked and treated. “We still have a lot of room to go identifying people who should be treated and treating them appropriately,” he said. “We recommend simplifying how the risk is calculated.”

Dr. Douglas Weaver of Henry Ford Health System in Detroit and immediate past president of the American College of Cardiology issued this comment about the study’s findings. “I find these results alarming,” he said. “Although we are making great strides in cholesterol management in patients with known heart disease, this study shows that many patients who could benefit from lipid-lowering medications and changes in their lifestyle and diet are still going unrecognized, and untreated.”

Weaver says that while doctors should be more aggressive about both testing and treating patients with high levels of LDL cholesterol, people over 20 also need to take it upon themselves to ask for screening.