by Amanda Barrett, MA
On July 13, 2004, a government-appointed panel of experts from the National Cholesterol Education Program (NCEP) issued an update on cholesterol guidelines for men and women considered at risk of heart attack or stroke .
This is the second update to the guidelines since their inception in 1993, and is based on five major clinical trials of statin therapy (a cholesterol-lowering pharmaceutical treatment) conducted since the release of the first update in 2001. All five of these trials demonstrated a direct link between low low-density lipoprotein (LDL, or bad) cholesterol levels and reduced risk of major coronary events, indicating that lower levels than were previously recommended are preferable. Consequently, the update essentially does two things:
- It lowers the limit at which LDL levels are considered too high and potentially in need of drug treatment from 130 milligrams per deciliter (mg/dL)[3.4 mmol/L] to 100 mg/dL (2.6 mmol/L) in very high-risk people. It acknowledges that some very high risk persons with LDL less than 100 mg/dL (2.6 mmol/L) could be treated with drugs.
- It offers, as an option, lowering the ideal goal of LDL treatment from 100 mg/dL (2.6 mmol/L) to 70 mg/dL (1.8 mmol/L) in very high-risk people.
- Very-high risk is defined as persons who have had a recent heart attack or who have known vascular disease plus other serious risk factors (diabetes, smoking, metabolic syndrome).
High levels of LDL cholesterol and/or low levels of high-density lipoprotein (HDL, or good) cholesterol, are major risk factors for heart attack and stroke. Heart attack and stroke are the first and third most common causes of death, respectively, in the United States today (cancer being the second). Each year, more than a million people in the US have a heart attack, and about half of them die from it.
The good news is that most persons can control major heart disease risk factors, including cholesterol levels, smoking, excessive weight, lack of exercise, high blood pressure , and type 2 diabetes . Increasing age, having a family history of heart disease, and being male, however, are risk factors for heart disease that cant be controlled. All people over age 20 are advised to have their cholesterol levels checked every five years. A total cholesterol level (including both HDL and LDL) over 200 mg/dL (5.2 mmol/L), or an LDL level over 130 mg/dL (3.4 mmol/L), is considered moderately high in the general population. A person with a cholesterol level over 240 mg/dL (6.2 mmol/L) has more than twice the risk of heart disease compared to someone whose cholesterol is below 200 mg/dL (5.2 mmol/L). A Run-Down of the GuidelinesThe guidelines propose different recommendations depending on a persons degree of risk of heart attack within the next ten years. This risk is determined by the presence of several risk factors, including history of heart attack or stroke, unstable or stable angina (chest pain), history of coronary artery procedures, evidence of clogged arteries (myocardial ischemia), diabetes, metabolic syndrome, high LDL cholesterol, low HDL cholesterol, high blood pressure, smoking, family history of heart disease, and age. There are four major risk levels: high risk (over 20% chance of heart attack within ten years), moderately high risk (10% to 20% chance), moderate risk (under 10% chance), and lower risk (0-1 risk factors).
To calculate your own risk, go to the National Cholesterol Education Program's 10-Year Risk Calculator . The new guidelines do not change cholesterol management recommendations for those at lower or moderate risk of heart attack, only for those at moderately high and high risk. Major changes are outlined in the table below:Risk Category2004 recommendations based on LDL levelsMajor change from 2001 recommendations?High-risk and very high-risk Drug therapy: definite above 130 mg/dL* (3.4 mmol/L), optional between 100-129 mg/dL (2.6-3.3 mmol/L) YesModerately high-riskDrug therapy: consider if above 130 mg/dL (3.4 mmol/L)YesModerate riskDrug therapy: consider if above 160 mg/dL (4.1 mmol/L)Overall treatment goal of LDL levels less than 130 mg/dL (3.4 mmol/L)NoLower riskDrug therapy: consider if above 190 mg/dL (5.0 mmol/L)No * milligrams per deciliter (millimoles per liter)The guidelines also now state that drug treatment for high-risk patients must be aggressive enough to achieve at least a 30% to 40% reduction in LDL levels, indicating higher doses more often. Finally, the update maintains the importance of initiating therapeutic lifestyle changes (TLC) in high-risk personsregardless of cholesterol levelsince TLC can reduce cardiovascular risk in several ways besides lowering cholesterol.
Recommended Treatment Pharmaceutical TherapyBy drug treatment, the guidelines refer mainly to the prescription of HMG-CoA reductase inhibitors, commonly known as statins. Other pharmaceutical treatment options include resins, nicotinic acid, gemfibrozil, and clofibrate. Statin medications work by blocking an enzyme (HMG-CoA reductase) that helps the body make cholesterol. Statins are distributed under the brand names Lipitor, Mevacor, Zocor, Pravachol, Lescol, and Crestol. Currently, approximately 12 million Americans are prescribed some type of statin medication.Statin drugs have proven to be highly effective in reducing cholesterol levels hence the new guidelines based on evidence from five major clinical trials of statin therapy. According to the FDA, statins can lower LDL cholesterol by as much as 60%, and in one 2002 meta-analysis, statins lowered cholesterol anywhere from 18% to 55%, depending on drug type and dosage, while they increased healthy HDL levels by 5% to 15%. Beyond cholesterol levels themselves, statins have been shown to reduce risk of a coronary event by as much as 30% and mortality from such an event by 20%. Furthermore, statins are generally highly accepted by patients and have few serious side effects. Common side effects include nausea, abdominal pain, gas, heartburn, and headache. More serious and rare side effects include muscle pain (myositis), joint pain, sleep disturbances, blurry eyesight, and decreased sexual ability. Very rarely , myositis can develop into rhabdomyolysis , a condition that can cause kidney failure and even death. The statin drug, Baycol, was actually recalled in 2001 after being linked to 31 rhabdomyolysis-related deaths. In 2005, the FDA denied a petition to remove one other statin from the market because of reported kidney complications. Statins should not be used in people with active liver disease, or during pregnancy or lactation. Some drugs should be avoided while taking statins in order to decrease the risk of myopathy, so discuss your current regimen with your doctor before beginning statin therapy.
Lifestyle Therapy The TLC that the update recommends are basically a set of heart-healthy lifestyle modifications. TLC includes eating a diet low in saturated fat and cholesterol, getting regular physical activity, and achieving overall weight management. Diet and lifestyle have been the mainstays of cholesterol treatment since well before statins came along. In fact, research has shown that some dietary regimens are just as effective as statin medication at lowering cholesterol. According to a 1998 study, LDL levels were reduced by 40% in patients with cardiovascular disease who followed a low-fat, vegetarian diet and performed 30 minutes of moderate exercise daily. Even though a 2006 study in the prestigious journal JAMA reported no benefit from a low fat diet, it is unclear how effectively study participants adhered to the diet. Other studies do suggest benefits from significant fat reduction and substitution of monounsaturated (vegetable) fats for animal fats. Moreover, diet and exercise have no adverse side effects (barring potential injury), and can help relieve risk factors for heart disease other than high cholesterol. Diet and exercise can also reduce weight, lower blood pressure, and control diabetes. However, beneficial changes to diet and exercise habits are extremely difficult to achieve, so people may be less likely to successfully lower their cholesterol in this way. Popping a pill is clearly the easier option.
Implications for the Future In the end, diet and exercise remain the first-line treatment option for high cholesterol in those at low to moderate risk for heart disease. And, most certainly, they are measures of prevention that everyone should heed. The new guidelines recommend aggressive drug treatment only for those at high risk for an adverse coronary event. The 2006 "Asteroid study" found that in very high risk individuals an average reduction of LDL by over 50% (to under 70 mg/dL [1.8 mmol/L]) led to actual regression of coronary artery plaque, though the degree of reduction in volume of plaque was under 10%. These findings are important but further studies are needed to insure that the benefits translate into decreased heart attack risk. Some critics of the new guidelines argue that its unwise to call for such a major increase in drug prescription while allowing diet and exercise goals to fall by the wayside. They feel that dependence on drugs over willpower is ultimately a trend for the worse. Some even claim that members of the NCEP expert panel have financial ties to statin companies that will profit from the new guidelines.On the other hand, according to the updates authors, high-risk patients are still urged to incorporate TLC into their treatment regimen; however, the crucial fact is many of them simply cannot lower their cholesterol levels sufficiently, or fast enough, by diet and exercise alone. In essence, having failed to keep cholesterol levels lower, drug treatment is the best remaining option for those at high riskespecially when faced with heart attack and stroke.
Furthermore, burgeoning research suggests that intense statin therapy may be lifesaving for patients who have already experienced an acute coronary event, such as a heart attack, and are thus at severe risk for a repeat event. RESOURCES: American Heart Associationhttp://www.americanheart.org National Heart, Lung and Blood Institutehttp://www.nhlbi.nih.gov References: American Heart Association. Available at: http://www.americanheart.org . Grundy SM, Cleeman JI, Bairey Merz CN, Brewer HB, Clark LT, Hunninghake DB, Pasternak RC, et al. Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III guidelines. Circulation . 2004; 110:227239 Healy, B. Meet the cholesterol busters. US News & World Report . March 22, 2004. Available at: http://www.keepmedia.com/ShowItemDetails.do?item_id=395621&oliID=255&bemID=l/sjnYFhOG3jl2DVcd+7gQaa2208 . Accessed September 13, 2004. Henkel, J. Keeping cholesterol under control. FDA Consumer Magazine . Available at: http://www.fda.gov/fdac/features/1999/199_chol.html . Accessed on September 13, 2004.
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Last reviewed April 2006 by Lawrence Frisch, MD, MPHPlease be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.