What Statins Actually Do And Why You Might Need To Take Them

After last week's controversial Catalyst program on the ABC, some people may be wondering whether they should stop taking statins to lower their cholesterol. But before making such a decision, read this article and discuss your risk of heart disease or stroke with a doctor.

Pills picture from Shutterstock

About 2.6 million Australians take statins. And a recent analysis of Australian data found that over-treatment of people at low risk is more common than under-treatment of people at high risk.

This is problematic but it doesn't reflect a problem with the statins. Rather, it shows that people may not be appropriately informed about who benefits from taking this medicine.

What the trials say

While Catalyst highlighted that most of the major trials for statins have been funded by the pharmaceutical industry, it didn't explain their overall results.

A collaboration funded by the UK Medical Research Council, British Heart Foundation and Cancer Research UK (the Cholesterol Treatment Triallists Collaboration), brought together data from 26 trials involving 170,000 patients, to better understand what the trials found.

What they discovered was the results are remarkably consistent: they show statins reduce the risk of heart attack or stroke by about 20 per cent. This is true whether you've had a heart attack or stroke in the past or not.

There were fewer women in the trials, so the numbers for women are less precise but they're approximately the same as the overall numbers.

If your risk of having a heart attack or stroke over the next five years is 30 per cent , taking statins will reduce it to 24 per cent. If it's 10 per cent , your risk is reduced to 8 per cent. Obviously, the benefit is greater if your initial risk is higher (we'll come back to how to work this out later).

Heart attacks and strokes are serious events that most people want to avoid, and there's clear, solid evidence that statins reduce the chance of having one.

But like all drugs, statins also have side effects and the Catalyst program was correct in pointing out that these were probably underestimated in the trials. There are good reasons for this.

Trials often exclude people with early side effects, the elderly and people with other conditions, such as kidney disease. It would be unethical to continue giving a new drug to someone if they are experiencing side effects and do not wish to continue, so participants can withdraw from the trial at any time.

The age group and medical conditions for clinical trials are specified so it can identify the effect of the drug on the target group for treatment. But the side effects of statins have been investigated in many other studies and populations outside of those trials, and continue to be monitored.

The most common side effects are fatigue, exercise intolerance, cataracts, and sometimes, memory loss. On the other hand, statins may protect people from small strokes that could cause dementia. This is why the decision to take statins has to be a balance between their benefits and risks.

Who should take statins

In Australia, the National Heart Foundation, Kidney Health Australia, Diabetes Australia, and the National Stroke Foundation (the National Vascular Disease Prevention Alliance) have weighed up the benefits and risks of drugs to lower cholesterol.

They recommend medication for people who have a high absolute risk, which is more than a 15 per cent chance of having a heart attack or stroke over the next five years.

The absolute risk of heart attack or stroke is calculated by using all the major factors that predict risk – age (it gets more likely as you get older), sex (males are at higher risk), blood pressure, and cholesterol. Whether someone smokes or has diabetes also strongly impacts their risk profile.

Medication may also be considered for people at moderate risk (10 per cent to 15 per cent ), who haven't been able to reduce their risk with diet and exercise. Or if they have a strong family history of heart disease.

The decision to take statins should not be based on someone's cholesterol level alone unless it's unusually high. If you are between 35 and 74 years of age, and know your blood pressure and cholesterol level, you can calculate your own risk here.

The advantage of this approach (using absolute risk as the guide) is that people at high risk of heart attack or stroke who have normal cholesterol levels can still reduce their risk by taking statins.

At the same time, people with mildly elevated cholesterol levels who have no other risk factors (and are therefore unlikely to benefit) don't need to take them.

The balancing game

Regular exercise and a Mediterranean-style diet also lower the risk of heart attack and stroke, and are recommended for everyone, whether they have low, medium, or high risk. But for some people, this is not going to be enough.

The number of deaths from heart disease has fallen dramatically since its peak in the late 1960s and early 1970s. This is partly because of overall improvement of diet, efforts to stop smoking and control blood pressure.

But reducing cholesterol levels through drugs, such as statins, has also played an important role.

People on statins who are now questioning whether to continue take them should talk to a doctor about their absolute risk of heart attack or stroke. This calculation needs to be based on levels of cholesterol and blood pressure before starting medication.

If substantial lifestyle changes have recently been made, it may be appropriate to consider a trial period off statins.

Statins are no magic bullet and people who take them may still have a heart attack or stroke, even though their chance of having one is reduced. And the truth is that if a person has been taking statins and doesn't have a heart attack or stroke, we can't tell if that's because of statins or because they were never going to have one.

The best we can do is use data from trials and other studies to estimate the benefits and risks. Like all medications, statins are not inherently good or bad — whether they help someone depends on whether their likely benefit outweighs their side effects for an individual.

Carissa Bonner is a Research Coordinator and PhD Candidate in Public Health at University of Sydney. Jenny Doust is Professor of Clinical Epidemiology at Bond University. Carissa Bonner receives funding from an Australian Postgraduate Award and the National Heart Foundation of Australia. Jenny Doust receives funding from National Health and Medical Research Council. She was previously a member of the Pharmaceutical Benefits Advisory Committee which considered the effectiveness and cost-effectiveness of statins.

The ConversationThis article was originally published at The Conversation. Read the original article.


Comments

    The gist of that show from my point of view was that the original studies were massively skewed by the doctor who did them. Cholesterol, it seems does more good than harm in a normal healthy person. Even in the day, other doctors pointed out the flaws in his studies, but he had such political clout by the end, that everyone was ridiculed for arguing against it. In the mean time pharmaceutical companies have been, and still are, making a fortune out of a drug, that for the average person with mildly high cholesterol is doing more harm than good. The issue in the end, came down again, on sugar levels in food. India this week was reported to be taking up fast food with gusto and their kids are now getting fat too...! I notice also that the types of fats in foods discussed on that show were not mentioned in this article. Seems butter, which has been villainised all these years, is apparently better than margarine...!!

    Last edited 08/11/13 9:00 am

      That's what I took from the program, too - except for the butter v margarine thing - I'm happy to have a foot in each camp (or is that a knife in each tub?) on that one :)

      Margarine in the US is terrible and full of trans fats. Margarine in Aus is actually largely trans fat free. I say this as someone who is very pro butter and eats it regularly. This is because I have low blood lipids, particularly low LDL levels, so I can chase the benefits of butter without being concerned about the potential downsides. My diet is healthy enough that it fits in nicely.

      The claims the experts make about how margarine is worse than butter IS ABSOLUTELY TRUE, in the USA. In Australia it's not as easy as that. It depends on what your overall diet is like and what your blood lipids and other hormonal readings are.

      The show made some true points (about how it's not just about saturated fat intake and modern studies are showing this and is also a fact that the Heart Foundation agrees with). It veers too far into sensationalism though.

      Ancel Keys was a respected scientist. He never said that all and any fat was bad but that you have to have a moderate intake. Other people misrepresented his views leading to the 'all fat is bad' craze of the 80s. Ancel Keys was also the author of the Mediterranean diet which was the diet the show praised in the first episode. They somehow failed to mention this.

      What the episode didn't do was clear up the misunderstanding around cholesterol. What we call cholesterol is actually blood lipids in total, of which cholesterol is one and not a very important one in heart health. Dietary cholesterol doesn't seem to have much of an effect on our blood lipid profiles. Not nearly as much as fat intake, overall dietary intake and body fat, exercise habits, and genetics.

      This is what caused people to think that things like eggs were bad because they contain cholesterol.

      I haven't watched the second episode and can't comment but I'm pretty horrified if it is suggesting broadly that people should go off statins. All drugs have side effects but for the people who are on them the benefits outweigh the costs. People should be working to try and reduce their need for statins but you can't just go off them. There's no scientific backing for the claims that statins are extremely detrimental to health. I say this as someone with little respect for the knowledge of GPs.

      I was disappointed with the show because I find the misunderstandings surrounding blood lipids frustrating and I'm somewhat sympathetic with the work of Dr Bowden. I also hate how all our 'diet foods' take out the fat and have put in sugar. That is a terrible result.

      I don't think this show was that helpful in clearing things up though. The media never gives the balanced, boring middle of the road truth though when it comes to nutrition and health. Only wild claims and misrepresentations make for good headlines. Something like 'excess saturated fat intake is an important factor in a multitude of factors contributing to blood lipid profiles contributing to heart disease' will never be a headline.

      Last edited 08/11/13 10:10 am

    First you get a scientific study with a set of results. Then you have a article conclusion which summarises key findings. Then you have a science show which summarises the findings for the layman for the purpose of education. Then you have some journalists summarised the already twice summarised findings and you have the average person with no science background thinks their entire life is living a lie.

    If the findings are correct (and they'll be verified with further research), corrective action will filter through clinical trials and make appropriate changes to general medical practice. You'll then see a decrease in the prescription of certain drugs over a course of decades. People with no scientific or medical background obviously shouldn't willy nilly change their medical routine....

      I don't know why you think because a person has no science background, has no informed point to make on the subject. There's a plethora of information out there, and any layman with an ounce of sense can derive a valid opinion based on that information. If people didn't do this we would all just be sheep, doing whatever the hierarchy tells us to do no questions asked..!

    The article states "While Catalyst highlighted that most of the major trials for statins have been funded by the pharmaceutical industry, it didn’t explain their overall results." I don't believe this is at all accurate. The Catalyst program did explain their results, and covered at length the reduction in risk of heart attack and stroke. What it also covered (which is omitted from the above article) is that the studies also found NO reduction in overall mortality rates. That is that the studies showed a reduction in heart attack/stroke, however an increase in death by other causes, and overall no reduction in mortality rates.

    You really should read the latest analysis of the 2012-2013 Cochrane study published about 2 weeks ago:

    “Should people at low risk of cardiovascular disease take a statin?”

    BMJ 2013; 347 : f6123 doi: 10.1136/bmj.f6123 (Published 22 October 2013 )

    http://www.abc.net.au/catalyst/heartofthematter/download/StatinsshouldNOTbebroadedtowiderpopulation.pdf

    The bottom line:

    “Our calculations using data presented in the 2012 CTT patient level meta-analysis show that statin therapy prevents one serious cardiovascular event per 140 low risk people (five year risk <10%) treated for five years. Statin therapy in low risk people does not reduce all cause mortality serious illness and has about an 18% risk of causing side effects that range from minor and reversible to serious and irreversible. Broadening the recommendations in cholesterol lowering guidelines to include statin therapy for low risk individuals will unnecessarily increase the incidence of adverse effects without providing overall health benefit."

    Second episode showed how statin worked. Imagine a tree, many branches, at the end of ONE of those branches is cholesterol. At other branches are also many other chemicals used by body, one is needed by heart (watch episode). Where in this tree is the statin working, at the branch where needed? No, it works by cutting tree at trunk! You lose everthing.

    That Catalyst piece was not characteristic of the normally balanced reporting for that program. It presented a rather skewed view and tellingly had no local cardiologists supporting their argument. so much so that I initially thought it was a syndicated piece from a US network.

    They did gloss over some details to suit their message. Prescribing patterns in the US are very different vs here mainly due to the way health funds work. There are additional incentives for US doctors to prescribe certain medications ... and so, of course, over-prescribing occurs. To people who probably don't need statins. And who are exposed to the risks for little-to-no benefit. Also there is no disincentive for health funds to limit spending on these drugs as they just pass the cost onto customers. Perhaps there is an element of that in Aus too, but PBS and various other mechanisms act as a brake on reckless or inappropriate prescribing.

    Another important point is that statin do reduce risk of significant cardiovascular events (heart attacks etc) in those at risk. For them, the risks are far outweighed by the benefits.

    And it was a shame that there was little mention of the LDL-to-HDL cholesterol influences that statins also confer in addition to just reducing overall levels. It's the former that helps too. Not to mention that statins also confer further anti-inflammatory benefits beyond cholesterol lowering. A growing body of evidence shows people already taking statins survive pneumonia and other potentially hazardous infections better than those not taking them.

Join the discussion!

Trending Stories Right Now