As if you need another reason to avoid statins …
A couple of readers sent me a link to the latest post by Dr. Malcolm Kendrick, which is titled Statins and Amyotrophic Lateral Sclerosis. (You may have heard ALS referred to by its more common name, Lou Gehrig’s Disease.) Let’s take a peek:
With ALS, your brain remains unaffected, whilst your body dies around you. People suffering ALS are often the ones you see in front of the High Court asking for a change in the law, so that they can be assisted to die, rather than suffocating to death. Thus far, in the UK, the courts have remained impervious to basic, caring, humanity. [You may infer what my views are on this matter].
Now, I have known for many years that statins are likely to cause damage to nerve cells. Probably through a direct effect on inhibiting cholesterol synthesis. Synapses are made, primarily, of cholesterol. Cholesterol is required to maintain the health of the myelin sheath, that surrounds and protects neurones. Glial cells in the brain, sustain the myelin sheath by synthesizing their own cholesterol and transferring it across to neurones, and suchlike.
A couple of weeks ago I was sent the following paper that was published in the Journal Drug Safety. ‘Amyotrophic Lateral Sclerosis Associated with Statin Use A Disproportionality Analysis of the FDA’s Adverse Event Reporting System.’
You can read a summary of the study Dr. Kendrick analyzed here. He apparently has the full-text version and pulled out some interesting (or horrifying, if you prefer) findings. The paper lists the relative risk of developing ALS among statin-takers compared to the general population. As Dr. Kendrick explains:
An odds ratio, basically means increased (or decreased) risk of something happening relative to the standard risk of one. An odds ratio of two (2) means something is twice as likely to happen. An odds ratio of nine (9) means something is nine times as likely to happen. This can also be represented as 900% increase in risk.
Stripping these figures out, we find the following increased risk of ALS associated with the use of different statins. Some statins are more likely to enter the brain than others (atorvastatin, simvastatin and lovastatin) because they are lipophilic (attracted to lipids), these ones had higher ROR.
He listed the odds ratios in a table, so let me just summarize in words: compared to the general population, people taking Rosuvastatin (brand name Crestor) are nine times as likely on average to develop ALS. Horrifying, right? Actually, that’s on the low end of the spectrum. For Atorvastatin (Lipitor), the odds ratio is 17. For Simvastatin (Zocor), the odds ratio is 23 – again, that means people taking it are 23 times more likely on average to develop ALS. But wait, it gets even better. For people taking Lovastatin (Mevacor), the odds ratio is 107.
Two questions may have already popped into your mind. Here’s the first: since this is just an observational study, should we be concerned? I’ll let Dr. Kendrick answer that:
It is often said that association does not mean causation. However, this is only true up to a point. Most statisticians agree that an odds ratio > 6 represents proof of causation. When you find that people taking atorvastatin have a seventeen-fold increase in risk of ALS, this is proof of causation. The effect is too massive to be due to anything else.
A lot of the scary headlines produced by observational studies are based on what looks like a high risk (people who eat bacon are 20% more likely to develop bunions!) but isn’t – 20% more likely in this case would mean an odds ratio of 1.2. Nowhere close to 6.0. We can and should ignore associations of that variety.
But in this study, we’re talking about odds ratios ranging from 9.0 to 107. I’d pay attention.
The second question: why aren’t doctors beating down the doors of health agencies to scream that statin patients are developing ALS at an alarming rate? I’ll let Kendrick answer that as well:
Now, you may think this is one hell of a lot of people, surely someone would notice. In truth, an increase like this is unlikely to be spotted by anyone. Looking at the UK, each year you might expect to see an extra 3425 cases of ALS each year.
There are around fifty thousand General Practitioners in the UK. So, each GP might expect to see an extra statin related ALS case every sixteen years or so. Or a maximum of two in their working life. You would have to be exceptionally alert to associate one extra case of ALS every sixteen years to statin use.
Doctors aren’t noticing because a 23-fold increase in a very small number is still a small number. Dr. Kendrick did the math:
In short, in a population of fifty million people, not taking statins, we can calculate that around 1,250 would develop ALS every year.
On the other hand, in a population of fifty million people taking statins (atorvastatin and simvastatin) we can expect that figure to be multiplied by around twenty. Now instead of 1,250 people developing ALS, we can expect to see 20 x 1,250 = 25,000.
Still a very small number in absolute terms. Divide 25,000 by 50 million and you get 0.0005, or one in every 2,000 statin-takers. The study isn’t saying if you take a statin, you’re highly likely to develop ALS. It’s saying the small odds are multiplied.
But then again, the supposed life-saving benefits of statins are also very small. Even the most positive studies (which are certainly cherry-picked) suggest perhaps 1 in 100 people taking statins will avoid a heart attack – but only if they belong to a narrowly-defined group at high risk.
Here’s what one study said about how long statins actually prolong life:
The median postponement of death for primary and secondary prevention trials were 3.2 and 4.1 days, respectively.
Wow. A few extra days on average. Now balance that against the risks of muscle and joint pains, permanent muscle damage, diabetes, liver damage, memory loss and perhaps ALS.
And that’s why I once told a doctor who suggested I might try a statin to lower my (ahem) “high” cholesterol, “I wouldn’t take a statin unless you had a gun to my head and I was convinced you’d pull the trigger.”