There’s no question in anyone’s mind that the best method of improving cholesterol and thereby lowering the risk of heart disease is through lifestyle measures–diet, exercise and not smoking. Yet the fact remains that for the majority of Americans the most effective way to get their cholesterol to a healthy level is by combining these healthy habits with a cholesterol-lowering medication.
Studies have consistently found that, depending on the drug and the dosage prescribed, statins lower LDL cholesterol by 10 to 60 percent. The landmark Scandinavian Simvastatin Survival Study (1994), found a 42 percent decrease in deaths from heart disease and a 30 percent decrease in deaths from all causes among patients with heart disease who took the statin drug Zocor.
As a consequence of that and other studies, doctors have been prescribing statins for patients considered at high risk of a heart attack. About 10 percent of American adults are now taking a statin, and based on guidelines of the National Institutes of Health, that’s only about a third of persons who should qualify.
Sorting Out the Benefits
As deaths from heart disease have fallen by 36 percent over the past decade, the case for statins has been made. But if you read the newspapers, you may have some questions regarding potential risks and benefits. While one headline shouts: “Statins: The New Wonder Drugs,” another asks: “Have the Benefits of Statins Been Oversold?”
On one issue, the evidence is clear. Nearly all doctors agree that for high-risk patients–particularly those who have had a heart attack–statins are an effective way to prevent a recurrence. Most doctors also prescribe statins for other persons considered to be high risk–those with very high cholesterol or blood pressure, for example, or those with a close family member who has had a relatively early heart attack or stroke.
Even for persons considered at low risk of a heart attack, some studies show a 30 percent decreased risk associated with statin use. But since the number of heart attacks in this group is low anyway, the value of that benefit has to be questioned. Most individuals prescribed statins take them for the rest of their lives. Results from the ongoing West of Scotland Coronary Prevention Study, however, found that men taking pravastatin had a reduced risk of having a heart attack or dying from a heart-related cause for at least 10 years after they stopped taking the drug. This was probably because the drugs have benefits beyond merely lowering LDL cholesterol.
Plaque deposits in arteries take years to develop and are not so easily broken down simply by removing some of the LDL cholesterol that feeds them. Studies have shown that the effect of statins on plaque deposits is small compared to their effect on LDL cholesterol. Yet statins start to work within a matter of weeks.
Doctors now believe that, in addition to lowering LDL cholesterol, these drugs may work by reducing inflammation and oxidation, improving the healthy dilation and contraction of blood vessels and preventing the breakdown of existing plaque deposits that often leads to the formation of blood clots.
One study published in The Lancet theorized that statins may act as vitamin D analogues, and that these actions may explain many of the unexpected benefits that have been attributed to statins.
Subjects in the West of Scotland study who took pravastatin had a reduced incidence of diabetes compared to those taking placebo. Those with organ transplants had a reduced rate of rejection. And women taking statins had greater bone density than other subjects.
All of these possible “side benefits” are based on observational studies and must be confirmed by randomized, controlled studies. Early reports of a decreased risk of Alzheimer’s disease associated with statin use was not confirmed in one recent study.
More promising are results of a study of nearly 25,000 heart failure patients. Those who took statins over a two and one half year period were 43 percent less likely to die and 30 percent less likely to be hospitalized than patients not taking statins. In another study, patients with a dangerous heart arrhythmia taking statins were 78 percent less likely to die compared to those not taking statins.
Simvastatin has been used successfully in the treatment of multiple sclerosis. And a controlled study found atorvastatin superior to placebo for the treatment of rheumatoid arthritis. In all of these instances, the benefits attributed to statins were not because of their effects on LDL cholesterol.
With a growing list of potential benefits, some observers have begun to talk of statins as miracle drugs and to recommend widespread use. You may have heard similar claims in the past for substances such as vitamin E and gingko biloba. In fact, all drugs come with a risk of adverse, as well as beneficial, effects.
For statins, adverse effects include muscle pain and weakness and, in rare cases, a severe breakdown of muscle tissue that leads to kidney failure. The drugs can cause severe liver damage, and some recent reports have linked the use of one statin to neurological and memory problems. Statins may also slow the body’s production of coenzyme Q10, a substance that helps cells use energy. The most serious effects, of course, are rare.
While you should not be scared away from taking statins because of these potential problems, neither should you take lightly long-term use of any drug. Before prescribing a statin–or any drug–your doctor will look carefully at the risk-benefit profile of the drug being considered as it relates to your continued good health.
Michelle Herbert Thomas, PharmD, CDE
Clinical Director
