In the vast majority of people who experience muscle pain or weakness while taking a statin, those symptoms are not related to the statin, a new individual patient data meta-analysis of randomized controlled trials shows.
The Cholesterol Trialists Collaboration meta-analysis examined 19 large randomized double-blind trials that compared statin therapy with placebo and involved almost 124,000 patients.
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“Our results show that, in people who experience muscle symptoms in the first year of taking a statin, those symptoms are actually due to the statin in only 1 of 15 of those people. For the other 14 of the 15 people who experience muscle symptoms in the first year of taking a statin, that muscle pain is not due to the statin,” lead investigator Colin Baigent, MD, said.
After the first year, there was no difference in muscle symptoms between patients taking a statin or those taking placebo.
Dr. Baigent, who is director of the Population Health Research Unit at the University of Oxford (England), presented the data on Aug. 29 at the European Society of Cardiology 2022 Congress.
It was also simultaneously published online in The Lancet.
Dr. Baigent explained that statins very rarely cause serious muscle adverse effects with biochemical evidence of cellular damage, such as myopathy (which occurs in less than 1 in 10,000 patients per year) and rhabdomyolysis (which occurs in about 0.2 per 10,000 patients per year).
The effect of statins on other less serious muscle symptoms without biochemical evidence of cellular damage is less clear, but misinformation about the risks have arisen from nonrandomized studies, with social media and press reports suggesting that the risk for muscle symptoms with statins is extremely common, Dr. Baigent said.
In response to this, the Cholesterol Trialists Collaboration put together a new program of data collection, validation, and analysis to provide reliable information from large double-blind randomized trials that are free from bias and confounding.
“Overall, when we look at all these data, we find there is about a 3% relative increase in the risks of experiencing muscle pain or weakness with a statin versus with placebo,” Dr. Baigent reported.
Muscle pain or weakness was reported by 16,835 of 62,028 patients taking a statin, (27.1%), compared with 16,446 of 61,912 patients taking placebo (26.6%), for a rate ratio of 1.03 (95% confidence interval, 1.01-1.06).
In absolute terms, the results show a rate of 166 reports of muscle symptoms per 1,000 patient-years in those taking a statin, compared with 155 per 1,000-patient-years in those taking placebo in the first year. This gives a rate ratio of 1.07 and an excess of 11 cases of muscle pain or weakness per 1,000 patients in the first year of statin therapy.
“The very small excess of muscle symptoms in the statin patients were generally mild, with most patients able to continue treatment,” Dr. Baigent added.
After the first year, the rate of muscle pain or weakness was exactly the same in the statin and placebo groups, at 50 per 1,000 patient-years.
“Therefore, for the vast majority of people who experience muscle pain or weakness on a statin, those symptoms are not due to the statin itself. It is due to something else, which could be ageing, thyroid disease, or exercise,” Dr. Baigent said. “After the first year of taking a statin, there is no excess risk of muscle pain or weakness at all.”
“To summarize, the excess risk of muscle pain or weakness with statin use is tiny, and almost nonexistent after the first year,” he added.
“Muscle pain is very common in the general population, and it was very common in both patients taking a statin and those given placebo in these randomized trials. We can only detect a difference by looking at all the data combined in this enormous study. And we now know for sure that over 90% of cases of muscle symptoms experienced by people taking a statin are not due to the statin.”
The researchers also looked at statin intensity and found that the more intense statins tend to cause slightly more muscle pain. “There was also some evidence, although this was not very clear, that the muscle pain with the more intensive statins may persist for longer than 1 year,” Dr. Baigent said.
But in terms of different moderate-intensity and high-intensity statins, there was no evidence of differences in muscle pain between the individual statin brands, he added.