Trial finds no link between statins and muscle pain

Patients who stop taking statins due to perceived side effects may be unnecessarily putting themselves at increased cardiovascular risk, new research into the links between muscle pain and the drugs has shown.

Professor Thomas MacDonald, a cardiovascular researcher at the University of Dundee, helped design and analyse the StatinWise study, led by London School of Hygiene and Tropical Medicine. The trial found there was no overall effect of statins on the frequency or severity of muscle symptoms compared with placebo in people who had previously reported severe muscle symptoms when taking statins.

Statins are widely used to prevent heart disease and stroke by lowering cholesterol levels and while severe side effects are rare, many people believe these drugs can cause muscle pain and stiffness, even though there is no clear evidence to support this. 

This belief has led to patients stopping treatment, exposing them to an increased risk of serious cardiovascular events. To address this uncertainty, the StatinWise team set out to establish the effect of statins in people who had previously reported muscle symptoms when taking the drugs.

Patients who participated were randomly assigned to a sequence of six, two-month treatment periods during each of which they received either statins or a placebo. Neither patients, nor their GP, knew which tablet they were receiving. 

At the end of each treatment period, participants rated their muscle symptoms, defined as pain, weakness, tenderness, stiffness, or cramp of any intensity, on a 10-point scale. Overall, the researchers found no difference in muscle symptom scores between the statin and placebo periods.

“This is a significant finding because the benefits of taking statins are considerable and so deciding to stop taking them means foregoing these benefits,” said Professor MacDonald. “Statins are very effective at reducing cholesterol. Every 1mmol/l of serum cholesterol fall translates to a more than 20% reduction in a person’s chances of experiencing a serious cardiovascular event. That is hugely important in a country like Scotland with high rates of cardiovascular diseases.

“Doctors are well used to patients complaining about muscle pain, stiffness and cramps when on statins. In clinical trials, these symptoms were only noted in only around 2-3% of cases but in usual practice the figures are more like 20-30%, which doesn’t make much sense.

“People experience muscle aches and pain all the time, particularly in the group most likely to be taking statins, but the narrative that statins can cause these symptoms has taken hold and patients often jump to this conclusion and stop their medication, putting themselves at much higher risk of heart disease.

“A very small number of people may be genetically predisposed to statin intolerance but many more are putting themselves at risk because of perceived side effects that aren’t actually linked to statins.”

The StatinWise findings are based on 200 patients (average age 69.5 years) from 50 general practices in England and Wales who had recently stopped or were considering stopping treatment with statins because of muscle symptoms. Each patient was part of an individual randomised, placebo-controlled trial (known as an n-of-1 trial). When combined, the results can be used to assess the overall effect of a treatment.

The research also found no differences for the effect of muscle symptoms on aspects of daily life (general activity, mood, ability to walk, normal work, relationships with other people, sleep, and enjoyment of life) between the statin and placebo periods. Withdrawals because of intolerable muscle symptoms were 18 participants (9%) during a statin period and 13 (7%) during a placebo period. 

Two-thirds of those completing the trial said they planned to restart long term treatment with statins after seeing their results, an outcome that Professor MacDonald believes has the potential to overcome statin hesitancy in the future.

“Most of the patients who were shown their results are now back on statins and accruing the benefits of this treatment,” he said. “I believe that if we can bring this type of trail into clinical practice and ask our patients to stop and start statins, while monitoring their symptoms, rather than stopping completely then we will be able to significantly reduce fatalities and serious cardiovascular events.

“It is not difficult to carry out a trial on a single person to find if statins are suitable for them. Being able to show a patient that their symptoms did not significantly differ during the statin and placebo periods may just save their life.”

The research is published today in the British Medical Journal.