Are people taking too many cholesterol pills?
Although the worldwide consumption of lipid-lowering drugs keeps growing, some recent studies cast doubt on their advisability
Cholesterol is losing relevance as an indicator of health; at least when taken as an isolated factor without taking into account other parameters. However, although some serious studies downplay its ability to predict cardiovascular events in healthy people, the consumption of pills to reduce it keeps growing throughout the world.
“Perhaps we shouldn’t ask if they are many or too few, but if we are taking them correctly,” says Daniel Escribano, coordinator of the dyslipidemia group of the Spanish Society of Family and Community Medicine (semFYC). What he suggests is that people who are most at risk of cardiac events might even be under-medicated, while others, less likely to suffer them, could be taking them unnecessarily.
Reducing the cholesterol no matter what and as much as possible is now an old dogma. The scientific evidence that is available today conditions it to many other factors; if it became known as the key parameter to consider in an analysis it was because its presence was found to be associated with the risk of cardiovascular events, but it is still a relatively recent field, barely a few decades old, and it has become more nuanced.
What is measured is not the cholesterol itself, but some indirect indicators: the lipoproteins that carry it through the blood. In fact, there are no different types of cholesterol – there are different types of lipoproteins, and one of them, LDL, in large amounts, can cause atherosclerosis, the accumulation of fat in veins and arteries that can lead to heart attacks, strokes and other events.
As the differences between lipoproteins became known, it was found that the risk of these events was not so much associated with cholesterol itself but with the LDL, which is also known as bad cholesterol.
What lipid-lowering drugs (commonly known as statins) actually do is lower LDL levels and, thus, coronary risk. At least, that is the theory; as cardiologist José Abellán from the Santa Lucia de Cartagena University General Hospital (Spain) explains, there is a very solid consensus that a low level of LDL is essential in people who have already experienced a cardiovascular event, to prevent it from happening again.
The nuances apply especially to healthy people, or those without other risk factors. A review of studies published in 2022 concluded that, for the general population, the absolute benefits of statins are “modest.” If the subjects that were included in all the studies were to be divided into two large groups – one treated with the drug and the other with a placebo – the relative reductions of the former would be 9% for all causes of mortality, 29% for myocardial infarction and 14% for cerebrovascular accident. Told this way it sounds like an argument for the medication, but in absolute terms, the reductions were much smaller: 0.8%, 1.3% and 0.4%, respectively.
What is the difference between relative and absolute risk? In a hypothetical disease that causes 1% mortality, a drug that lowers it to 0.8% is reducing the relative risk by 20%, but the absolute risk by only 0.2 points. Taking the drug, a person suffering from the ailment goes from a very low chance of dying to just a little less; the difference in the prognosis is statistically tiny, although that little bit is a reduction of 20%. And, even though the personal risk hardly changes, taken in an entire population this percentage is large: if a million people get sick (of which 10,000 would die) the drug can save 2,000 lives. But to know if it is worth prescribing or not, the side effects would have to be considered, as the risk may outweigh the benefit.
Paula Byrne, one of the authors of the meta-analysis on the benefits of statins, explains it very clearly in an article published last December. In two groups of 1,000 people with high cholesterol, one treated with drugs and the other with a placebo, the vast majority simply did not have a heart attack, regardless. Among those who took an innocuous substance there were 45 serious events, while those who took statins registered 32.
If statins were free of side effects, there would be no question that these 13 events (including eight deaths) are worth avoiding. But they do have them, and sometimes they are not mild. In Byrne’s example, more than 950 people who were medicated were not going to suffer any complications in any case. This is why the authors recommend informing patients of these statistics, so that they can make their own decisions.
However, clinical guidelines have been adapted to the evidence, and in the last 15 years the recommended cholesterol levels have changed. Escribano explains that the number that indicates cholesterol is no longer an absolute reference, but that risk factors such as sex, age, stress, physical activity, diet and smoking are taken into account, as well as personal and family history: someone who is young, healthy and active will do better with a high level of LDL than a sedentary smoker whose father died of a heart attack. Doctors should not automatically prescribe statins to a patient with high cholesterol; only taking all these factors into account and if other approaches have failed.
Types of cholesterol that are not measured
Still, health is not an exact science. There are borderline situations, with high values and medium risk levels, in which there is no clear solution. For them, standard blood tests may fall short. Within the largest types of lipoproteins there are other subtypes and other substances that are not measured and which could prove useful when making clinical decisions; LDL-P (a type of LDL) is a more accurate indicator of risk and can be calculated by measuring a protein called APOB that is not included in conventional tests.
Another type of cholesterol that is not usually analyzed is the lipoprotein(a), whose level can also help reach a decision regarding which treatment to give patients who are not clearly at high or low risk. “It should be measured at least once in a person’s lifetime to determine cardiovascular risk, but this is not always possible,” says Escribano. As with many other tests, primary care physicians sometimes request this type of analysis and sometimes they do not.
In any case, he points out that such meticulousness is not necessary for the majority of people and that, in the absence of any major risk factors or some genetic predisposition to rare high cholesterol, diet and exercise should be enough medicine for most.
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