"Statins are not effective at lowering cholesterol levels for half of patients," the Daily Mirror reports.
Statins are a widely used and well established medicine for lowering cholesterol.
A large body of evidence has shown that statins are effective in reducing so-called "bad cholesterol", which in turn can reduce the risk of heart disease and stroke.
A new study assessed GP records for more than 160,000 patients in the UK who'd had a cholesterol check in the 2 years after they started statins.
Half of patients did not have an adequate response to statins: their cholesterol levels had reduced by less than 40%.
These patients had a slightly higher risk of future cardiovascular problems than those who'd had a good response.
But this does not mean statins do not work. We do not have enough information about the people who did not respond to statins, such as whether they took the medicine as prescribed.
And those who did not respond to statins tended to be on lower doses than responders.
Whether some people could be less responsive to statins needs to be looked into.
The study also highlights the need for doctors to monitor a patient's response and change their medication if needed.
People prescribed statins should not stop taking them. This could increase their risk of having a heart attack or stroke.
You should speak with your doctor if you have concerns.
Where did the story come from?
This study was carried out by researchers from the University of Nottingham and was funded by the same institution.
The article was published in the peer-reviewed journal Heart.
The UK media reported the study accurately and included some helpful commentary from independent experts.
What kind of research was this?
This cohort study looked at a large number of people who were prescribed statins to see the effect this had on their cholesterol levels.
A randomised controlled trial (RCT) is the best way to directly look at the effects of a medicine, where you can compare the effects of a treatment like statins with no treatment or with another cholesterol-lowering medicine.
But a practical drawback is that RCTs can be both expensive and time consuming to carry out.
Cohort studies are often used to assess the effects of medication because they allow you to study many more people than you can usually include in a RCT and follow them for longer periods of time.
The disadvantage is that you cannot account for differences between people who do and do not respond to statins.
What did the research involve?
The study used the GP records database (UK Clinical Practice Research Datalink) to identify 183,213 patients who started taking statins between 1990 and 2016.
Eligible patients had to have at least 2 cholesterol measures taken: 1 in the 12 months before taking statins and 1 in the 24 months after starting statins.
The researchers excluded anyone who'd experienced cardiovascular problems, such as a heart attack or stroke, before starting statins.
This left them with data for 165,411 patients (47% women), who had an average age of 62.
They looked at the number of patients who'd failed to achieve at least a 40% reduction in their low density lipoprotein (LDL) "bad" cholesterol.
This is the adequate treatment response currently recommended in national guidelines.
They also looked at whether there were any cardiovascular events like a heart attack or stroke.
The researchers adjusted for various confounding factors that may influence the results, such as:
- baseline cholesterol levels
- how long the patients were on statins
- use of other medications
- blood pressure
- history of smoking
- alcohol use
- socioeconomic status
What were the basic results?
They found half of the patients assessed (51%, 84,609) did not achieve an adequate 40% reduction in their LDL cholesterol levels.
Non-responders were more likely to have been prescribed lower strength statins.
For example, 29% of non-responders were taking low dose and 66% medium dose, compared with 18% low dose and 76% medium dose among responders.
Non-responders had a slightly higher risk of future cardiovascular problems than responders (adjusted hazard ratio 1.22, 95% confidence interval [CI] 1.19 to 1.25), though the actual difference was fairly small.
Over the course of 10 years on statins, 22.6% of non-responders would experience a cardiovascular problem, compared with 19.7% of responders.
How did the researchers interpret the results?
The researchers concluded: "Optimal lowering of LDL cholesterol is not achieved within 2 years in over half of patients in the general population initiated on statin therapy, and these patients will experience significantly increased risk of future [cardiovascular disease]."
This valuable study made use of a large number of general practice records to look at the cholesterol response of hundreds of people taking statins.
It shows that half of people on statins are not achieving the required 40% reduction in their LDL cholesterol levels.
This is of some concern and highlights a need for doctors to look into this further to find out why this might be the case.
For example, it could be that statins do not work so well for certain people.
But there are a few points to consider.
The researchers adjusted for many factors that could influence the results, but we do not know enough about the individuals to be sure there are not any differences between responders and non-responders that could have affected the results.
For example, we do not know whether the participants took the medication as prescribed.
Those who did not respond to statins did have a higher risk of further cardiovascular problems. But the absolute size of the difference was still fairly small: only a 3% risk increase over the course of 10 years.
Notably, those who did not respond were on lower doses, but the study cannot tell us that specific statins or particular doses "do not work" because we do not know enough about why doctors prescribed as they did.
Importantly, the results of this study do not apply to people who have been prescribed statins after a previous heart attack or stroke: they will nearly always be prescribed higher dose statins.
The study highlights the need for doctors to review the cholesterol response in people who take statins.
National guidelines recommend that people who have been started on statins should have their cholesterol rechecked after 3 months.
If they have not achieved at least a 40% reduction in LDL cholesterol, the guidelines recommend:
- checking that the person is taking the medication as prescribed
- promoting general healthy living advice through diet and exercise
- considering increasing the dose
It's important that people do not stop taking statins without speaking to their doctor, as this could increase their risk of having a heart attack or stroke.
Analysis by Bazian
Edited by NHS Website
Links to the headlines
The Guardian, 16 April 2019
BBC News, 15 April 2019
Mail Online, 15 April 2019
Daily Mirror, 15 April 2019
The Telegraph, 15 April 2019
Links to the science
Heart. Published online April 15 2019