Friday September 9 2016
Statins help reduce the production of LDL cholesterol
"The benefits of statins are hugely underestimated and far outweigh any harm," the Daily Mail reports.
A major review also argues that the risks of statins have been exaggerated by both the media and some sections of the medical profession.
The review in question explored a variety of evidence to weigh up the benefits and possible harms of the widely used cholesterol-lowering drugs.
It highlights that the benefits of statin therapy, which include reducing the risk of cardiovascular events like heart attack and stroke, far outweigh any possible side effects a patient may encounter as a result of the treatment.
Statins have been controversial since they were first introduced as they are mainly used as a preventative measure for people at risk of, but with no history of, heart disease.
The drugs are an obvious target for "overmedicalisation" claims – that is, doctors treating people who don't actually need treatment.
The drugs have been associated with potential risks, such as harming the liver or, very rarely, causing muscle weakness or damage.
The review notes, for example, that for every 10,000 people who take standard-dose statin therapy for five years, only five would experience muscle weakness as a result.
Comparatively, between 500 and 1,000 cases of heart attack or stroke would have been avoided by the same number of people.
The authors also note that many side effects reported in placebo-controlled trials of statins may not in fact have been directly caused by the drugs.
Often, people who claimed statins were causing side effects continued to have the same side effects when given a dummy treatment.
Ironically, many of the media sources talking about side effects being "dangerously exaggerated" are the same ones exaggerating them in the first place – as we discussed in more detail in June 2016.
Dr Maureen Baker of the Royal College of General Practitioners (RCGP) said: "We hope this research reassures patients that in the majority of cases statins are safe and effective drugs – but in most cases where adverse side effects are seen, these are reversible by stopping taking statins."
Who produced the review?
The review was carried out by researchers from a variety of international institutes, including the University of Oxford and the London School of Hygiene and Tropical Medicine in the UK, Johns Hopkins University in the US, and the University of Sydney in Australia.
The majority of researchers were funded by pharmaceutical companies. The study was published in the peer-reviewed journal, The Lancet.
The review was widely covered by a variety of both UK and international media outlets. The Daily Mail's headline read: "Statins ARE safe and we should give them to six million more people because benefits outweigh any harm, says biggest study ever".
But the review in question does not give such a definite opinion about the use of statins – rather, it highlights the importance of making an informed decision about any medical issue.
What evidence did they look at?
The review explored evidence from randomised controlled trials (RCTs) and observational studies, highlighting the strengths and limitations of each study design before delving into specific evidence on the safety and efficacy of statin therapy.
The authors argue that when it comes to weight of evidence, RCTs are more "weighty" as they carry less risk of bias than observational studies.
This is an important point – many of the reports about side effects and complications of statins came from observational studies, not RCTs.
The review generally reports outcomes in terms of the effects of taking a daily effective statin dose – for example, 40mg atorvastatin – in 10,000 patients over five years.
The methods behind how the literature was identified aren't described, and as such it isn't possible to say that this review was systematic in manner.
For example, the review doesn't mention whether literature databases were searched, search dates, search terms, or study eligibility for inclusion. This means there could be a chance that some relevant studies have not been included.
Proven beneficial effects of statin therapy
- Large-scale evidence shows that effective low-cost statin treatment, such as 40mg atorvastatin, can reduce low-density lipoprotein (LDL, or "bad") cholesterol levels by more than 50%. Five trials showed a reduction of 0.5mmol/L in LDL cholesterol levels after one year of therapy, 17 trials showed a reduction of 1.1mmol/L, and five further trials showed a reduction of >1.1mmol/L.
- The reduction in LDL cholesterol levels was associated with a proportional reduction in major vascular event rates, such as heart attacks and related deaths, strokes and coronary revascularisations. For example, evidence showed each 1mmol/L reduction in LDL cholesterol was responsible for about a 25% reduction in the rate of major vascular events, and reducing cholesterol by 2mmol/L could reduce risk by about 45%.
- The evidence indicated that reducing LDL cholesterol by 2mmol/L over five years in 10,000 people would prevent about 1,000 vascular events in people who were taking a statin after a previous heart attack or stroke (secondary prevention). This means the drugs would prevent further events in 10% of high-risk patients.
- For people taking statins because they had cardiovascular disease risk factors but had not yet had an event (primary prevention), the drugs would prevent events in 500 out of 10,000 people – benefiting 5%.
Possible harms of statin therapy
- Statin therapy has been linked with a rare risk of muscle weakness (myopathy) and possibly increases the risk of new-onset diabetes and strokes caused by bleeding (haemorrhagic stroke). Statistics show that typically for 10,000 patients who take a standard-dose statin for five years, five individuals would suffer from myopathy and 5 to 10 people would suffer from a haemorrhagic stroke. This means the event rates are extremely low. For new cases of diabetes, the risk was slightly higher – 50 to 100 new cases per 10,000 over five years.
- Any harmful effects caused by statin therapy can be reversed by stopping treatment, but the effects of heart attacks or strokes that occur when statin therapy has not been used may be devastating.
This review highlights that misleading claims made about the balance of safety and efficacy of statins may pose a serious threat to the public's health.
In the past, exaggerated reporting of side effect rates and the related media coverage may have led to some doctors having reservations about prescribing statins to patients who needed them.
The coverage may have also led to reduced compliance from patients as a result of raised awareness about perceived side effects.
Evidence shows statin therapy is underused by people at a high risk of suffering from a heart attack or stroke.
One such study showed that in Europe only 42% of individuals with prior cardiovascular disease were taking any form of cholesterol-lowering treatment.
Drug discontinuation rates are also high, particularly among people who have not suffered from recent cardiovascular events.
This review notes the importance of employing caution when making claims about the possible side effects of a drug, as patients and doctors may be dissuaded from using statin therapy despite the proven benefits.
This study reviews evidence from randomised controlled trials (RCTs) and observational studies to better evaluate the effects and safety of statin therapy.
It provides valuable data on the size of the benefits compared with the risks, informing a topic that has had much media coverage in recent times.
The researchers highlight that the benefits of statin therapy for people at risk of cardiovascular disease events far outweigh any possible side effects.
But it is still for a doctor and their patient to come to a conclusion about what the best treatment for them may be.
If you have been prescribed a statin, it is important that you keep taking this medication as prescribed.
If you have any concerns or experience any side effects you think could be caused by a statin, you should speak with your doctor.
They will be able to assess whether the effects could be caused by the drug and will be able to consider an alternative treatment if needed.
You can also reduce your cholesterol levels by making changes to your diet.
Try to avoid or cut down on the following foods, which are high in saturated fat:
- fatty cuts of meat and meat products, such as sausages and pies
- butter, ghee and lard
- cream, soured cream, crème fraîche and ice cream
- cheese, particularly hard cheese
- cakes and biscuits
- milk chocolate
- coconut oil, coconut cream and palm oil