Statins overprescribed for primary prevention
Even healthy people who don't suffer from a cardiovascular disease are prescribed cholesterol-lowering drugs, known as statins, if they meet certain risk criteria. However, for years the use of statins for primary prevention has been hotly debated among experts. Now, a new study aims to identify the benefits and harms of using statins for preventative care purposes.
Ultimately, using statins for preventative purposes is meant to ward off heart attack or strokes, though it is only effective in a few cases, says Milo Puhan, PhD, professor of epidemiology and public health at the University of Zurich in Switzerland.
“All people who take statins are at risk of experiencing the side effects," he said.
When deciding whether to prescribe statins to a patient, doctors use several risk factors, such as cholesterol level, BMI, and smoking to determine the likelihood of a person suffering a heart attack or stroke in the next 10 years. If this figure reaches or exceeds 10 percent, many medical guidelines recommend the use of statins; however, some guidelines put this number at 7.5 percent, including those from the American Heart Association and the American College of Cardiology, though they leave room for variation.
If these guidelines, most of which are drawn up by cardiology organizations, are to be believed, more than one third of all people between the age of 40 and 75 would have to take statins as a preventive measure—in other words, hundreds of millions of people around the world.
According to Puhan, however, these guidelines were drawn up without properly considering the unwanted side effects, such as muscle pain, cataracts, liver defects, or diabetes.
"The thresholds set by experts aren't based on any systematic studies,’ he said.
Striking a good balance between the benefits and the harmful side effects is therefore one of the great challenges of developing improved guidelines for preventive statin use. This is why Puhan and his team have carried out a comprehensive statistical modeling study.
The researchers systematically compiled all data from specialist literature that documents the benefits and side effects of the preventive use of statins. To include the view of patients in their model, they also performed a survey among healthy people about the significance of heart attacks, strokes and certain side effects.
Using this information, the scientists determined new thresholds for men and women across different age groups between 40 and 75. They also compared the benefits and unwanted side effects of four widely used statin preparations.
"Our study shows that today statins are recommended far too often," says Puhan.
According to his estimates, the newly set thresholds could cut the number of people who are given a recommendation to take statins by half.
The benefits of cholesterol-lowering drugs have been greatly exaggerated particularly when it comes to senior citizens. For the 70 to 75 age group, the study's model put the threshold at approximately 21 percent, meaning the benefits of statins outweigh the harm from potential side effects of statins only if there's a 21 percent risk or higher that a person will suffer a heart attack or a stroke in the next 10 years.
For men and women aged 40 to 45, the threshold is slightly lower, at 14 percent and 17 percent, respectively. The researchers also noted that two of the four examined statin preparations, atorvastatin and rosuvastatin, had a significantly better balance of benefits and harms than the other two, simvastatin und pravastatin.
Considering the study's findings, Puhan recommends that all people concerned should discuss their individual risk for cardiovascular disease, as well as possible side effects with their doctors before deciding whether to take statins as a preventive measure.