Statins for healthy people? Hang on a minute…

Statins for healthy people? Hang on a minute…

I’ve had a few emails today alerting me to reports of a study concerning the use of statins in healthy individuals. The study in question is a meta-analysis (grouping together of similar studies) of statin trials [1]. Part of this meta-analysis involved assessing the impact of statin therapy in individuals deemed to be at relatively low risk of cardiovascular events such as heart attacks and strokes. One of the stand-out findings of this study is that statins led to a statistically significant reduction in risk of ‘major vascular events’. This was even true for individuals at less than 10 per cent risk of vascular events over a 5-year period. This has led to the suggestion that statins used might be widened to even people at low risk of cardiovascular problems.

Before we swallow this idea, though, it is perhaps a good idea to see just how effective statins were found to be in this meta-analsysis. First of all, what is meant by ‘major vascular events’? Actually, this is a term that includes many different potential outcomes including fatal and non-fatal heart attacks and strokes and ‘revascularisation’ procedures (such as placing tubes called stents in the coronary arteries). When a lot of different outcomes are grouped together, it makes it much more likely that a ‘statistically significant’ results will emerge.

When the outcomes are narrowed a little, the results are less impressive. For example, when we look at risk of death from any vascular event (a heart attack or stroke), we find that statins did not reduce risk in individuals deemed to be at low risk (<10 per cent over 5 years). This, by the way, was even true for those who had known vascular disease.

The ‘positive’ findings from this study have, as is often the case, been expressed as reductions in relative risk. The risk of vascular events overall was 21 per cent lower for each 1 mmol/l (39 mg/ml) reduction in levels of low density lipoprotein cholesterol (LDL-C). However, when overall risk is low, then a relative risk reduction might not amount to much in real terms.

We’re told by the authors this meta-analysis that treating with statins prevented 11 major vascular events for every 1000 people treated for a period of 5 years. Put another way, 91 people would need to be treated for 5 years to prevent one major vascular event. Or in other words, only about 1 per cent of people treated with statins for 5 years will benefit (and about 99 per cent won’t).

Overall, lowering LDL-C by 1 mmol/l was found to reduce the risk of death by 9 per cent over a 5-year period. Again, this might sound like a positive finding to some, but the actual reduction in risk of death was 0.2 per cent per year. What this means is that at this level of cholesterol reduction, 500 individuals would need to be treated with statins for a year for one person to have his/her life saved.
The authors of this meta-analysis give us some soothing reassurances about the fact that the benefits of statins vastly outweighing the risks of adverse events such as myopapthy (muscle pain and weakness). They quote of the excess incidence of myopathy as 0.5 cases per 1000 people over 5 years. However, the source they quote is based on diagnosing myopathy once the marker for muscle damage (creatine kinase) is at least TEN TIMES the upper limit of normal. Many individuals will have significant pain and weakness with much lower levels of creatine kinase. Statins are also linked with adverse effects on the liver and kidneys, and increase risk of diabetes too.

Despite the very positive interpretation of the data by the study authors and the media, this meta-analysis shows us again what previous evidence has revealed: statins are highly ineffective in terms of improving health and saving lives. And their risks are generally downplayed.

Collectively, the authors of the meta-analysis are referred to as the Cholesterol Treatment Trialists’ (CTT) Collaborators, including researchers from Clinical Trial Service Unit and Epidemiological Studies Unit at Oxford University. The conflicts of interest statement which accompanies this paper informs us that: “Some members of the writing committee have received reimbursement of costs to participate in scientific meetings from the pharmaceutical industry.” I suppose this may account, at least in part, for a data interpretation that appears so heavily biased towards statins.

References:
Cholesterol Treatment Trialists’ (CTT) Collaborators. The effects of lowering LDL cholesterol with statin therapy in people at low risk of vascular disease: meta
-analysis of individual data from 27 randomised trials. The Lancet epub 17th May 2012
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Read the full atricle here.http://www.drbriffa.com/2012/05/18/statins-for-healthy-people-hang-on-a-minute/

Why statin side effects are likely to be much more common than official statistics suggest

 Why statin side effects are likely to be much more common than official statistics suggest

By : Dr John Briffa

In the UK, the most popular ‘drugs bible’ goes by the name of the British National Formulary (BNF). Within its pages is found a wealth of information about pills and potions that are available over-the-counter and by prescription, including indications and advice of dosages. A significant proportion of the pages in the BNF are taken up with information about contraindications (situations where the drug should be avoided or used with caution) and side-effects. This information is now to be found as part of the packet insert which comes with medication. I’ve known many, many people to read this information and decide that they’ll give the medication a miss.

One class of medication with a range of known side-effects are the statins. These cholesterol-reducing drugs are known to have the potential to cause symptoms such as muscle pain and fatigue, as well as cause damage to organs such as the liver and kidneys. About a year ago I was at a medical lecture, and one (doctor) member of the audience commented that he felt his patients experienced side effects from taking statins far more commonly than official statistics suggested. My own experience supports this observation.

Could there be an explanation for this phenomenon?

One explanation has to do with the design of statin studies. Quite often, individuals who are in poor health and perhaps at increased risk of side-effects are automatically barred from entering a study. Yet, in the real world, even people who are poor candidates in this respect may end up being prescribed a statin. Individuals with a history of problems such as muscular pain or damage to the liver or kidneys (all of which can be exacerbated by statins) are typically excluded from studies too, further reducing the chance that side-effects will arise.

Even those who make it through this screening process, however, may be subjected to what is known as an ‘run in’ period prior to the study. Here, individuals may be treated with a statin with idea being that individuals who are ‘non-compliant’ (do not take their medication as instructed) are weeded out. However, the run-in period also affords the researchers the opportunity to detect individuals who are susceptible to statin side-effects and stop them getting into the study proper.

In other words, in formal studies participants are often at a significantly lower risk of side-effects than those in the general population.

Another problem with conventional studies is how side-effects are defined. Muscle pain is a quite-frequent side-effect of statins. In extreme cases, statins can cause a break-down of muscle tissue known as ‘rhabdomyolysis’ which can have potentially fatal consequences. In some studies, the focus has been on rhabdomyolysis, which means less severe side-effects such as muscle pain or fatigue may ‘go missing’.

Another way in which the bar for side-effects can be set very high concerns the blood parameters used to detect damage. For instance, in a recent study muscle damage was only deemed to have occurred when muscle enzyme levels (a marker for muscle damage) were at least 5 times the upper limit of normal [1]. In this same study, liver damage (another potential hazard of statins) was only deemed to have occurred when liver enzymes were at least 3 times the upper limit of normal. In both cases, a more logical approach would be to regard a rise of any amount above the top end of the normal range as abnormal and significant. This would be more how it is in actual clinical practice.
The elimination of individuals prone to side-effects and the setting of the bar very high for abnormalities help explain why the side-effects from statins seem much more common in the real world than officially quoted statistics.

However, even in the real world, there might be under-recognition of the damage statins can do. That’s because, quite often, doctors will dismiss the idea that statins might be the cause for someone’s symptoms, even when scientific evidence supports such as link. For more on this, see here.

References:
1. Nicholls S, et al. Effect of Two Intensive Statin Regimens on Progression of Coronary Disease. NEJM 2011;365(22):2078-87
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Read the complete article here.