Everyone knows that a high cholesterol level can be bad for your health. Most people understand this relates to the risk of heart attack, and many are aware that cholesterol build-up is related to strokes as well.
The statins are a group of drugs that lower cholesterol levels by decreasing the rate of cholesterol production within the body. It is unknown, however, if this is the mechanism whereby the risk of heart attacks and strokes is lowered. Statins may be doing something else beneficial. Apparently drugs that lower cholesterol by other mechanisms are not as effective in preventing cardiovascular disease. The statin drugs include Zocor, Lipitor, Crestor, Mevacor, Pravachol, and Lescol. It has been proven that statin drugs lower the risk of death from any cause, death from heart attack and stroke, as well as non-fatal cardiovascular events.
Patients may assume these drugs lower the risk a great amount, but the results are not as optimistic as you might expect.
For patients who already have diabetes or cardiovascular disease, taking a statin regularly over the course of five years will reduce your risk of death from any cause from 9.6% to 8.5%. To achieve this reduction, 86 patients will need to be treated to prevent one death (the number needed to treat, NNT). Statin use reduces the risk of death from heart attack or stroke from 4.4% to 3.4%. This requires treating 109 patients to prevent one death.
Statins work best for patients under 65 years of age. In this age group, 68 patients need to be treated to prevent one cardiovascular event. In patients over 65, this requires treating 111 patients. For women the numbers are especially dismal: 326 women over age 65 must be treated with a statin for five years in order to prevent one cardiovascular event (heart attack, stroke, other), according to a meta-analysis in the medical journal Lancet, October 8, 2005.
If you’re like my patients, you probably thought taking a statin would reduce your risk by at least half. Not so.
This is why the U.S. Preventive Services Task Force does not recommend for or against screening women for high cholesterol who are not at risk for cardiovascular disease otherwise. Other risk factors include smoking, family history, diabetes, and obesity.
If you were 80 years old, would you take a drug that has a 1 in 326 chance of helping you? I wouldn’t. How about if you’re 55 and the odds are 1 in 10 that it will save your life? These are the sort of questions you should ask your doctor before beginning treatment for high cholesterol. The goal isn’t just to lower the number on a lab test. The goal is to decrease your risk of a potentially fatal or debilitating disease.
Copyright 2010 Cynthia J. Koelker, M.D.