Serious statin muscle side effects are rare for most people, new calculator shows

Serious statin muscle side effects are rare for most people, new calculator shows

Researchers at the University of Oxford have created a new calculator to estimate the risk of developing serious muscle disorders from statins. The tool, developed at the Nuffield Department of Primary Care Health Sciences, aims to help patients and clinicians make more informed decisions about medications used to prevent strokes and heart attacks.

The research, published in The Lancet Digital Health, found that serious muscle disorders are rare for the majority of people eligible for the treatment. More than 98% of those identified by GPs as eligible were predicted to be at low risk of such disorders over the next decade.

This finding comes amid a significant treatment gap. More than 60% of eligible people were not taking statins, according to the researchers, and some of those individuals are at high risk of stroke or heart attack.

Personalized Risk Assessment

The calculator is based on a clinical prediction model using anonymised health records from more than 5.6 million people registered with GP practices across England. To build the model, researchers used data from more than 1.7 million people and tested its accuracy using another 3.9 million records.

The model evaluates 22 routinely recorded factors to estimate risk over one, five and ten years. These factors include:

• Age, sex, and ethnicity
• Body mass index and smoking status
• Existing health conditions and previous muscle problems
• Vitamin D deficiency
• Medication use and statin prescription

The authors focused specifically on serious muscle disorders that lead to death or hospital admission. This excludes milder symptoms, such as muscle aches and pains, which are more common but often not caused by the medication. The study identifies severe conditions including myopathy, myalgia, and rhabdomyolysis, a dangerous state where muscle tissue breaks down and toxins leak into the blood.

"Serious muscle disorders are one of the most widely discussed concerns about statins, but our findings suggest that the risk is very low for the vast majority of people who may benefit from treatment."

Dr Ting Cai, Research Fellow in the Nuffield Department of Primary Care Health Sciences, University of Oxford, via phc.ox.ac.uk

Addressing the "Treatment Gap"

Statins, such as rosuvastatin, atorvastatin, and simvastatin, can lower LDL cholesterol levels by as much as 60%. However, fear of side effects often deters patients. In the United States, less than half of the 50 million people who could benefit from statins use them. Research shows about 40% of people prescribed the drug quit within three months, and up to one-third never fill their prescriptions.

Dr. Nishant Shah, a preventive cardiologist at Duke Health, noted that this concern is driven by a confluence of social media messaging, medical misinformation on non-peer-reviewed websites, and anecdotal family stories.

Experts suggest that risks are often overestimated. Dr. Steve Nissen, chief academic officer of the Heart, Vascular & Thoracic Institute at Cleveland Clinic, stated that in his 40 years of practice, he has never admitted a patient to the hospital for a statin-associated muscle disorder.

Clinical factors can influence risk. People with kidney disease or those taking certain other medications may face a higher risk. Vitamin D deficiency is also linked to muscle soreness during statin use, according to Dr. Nissen.

Clinical Application

The researchers intend for the calculator to be used alongside existing cardiovascular risk tools like QRISK. This allows doctors to weigh the benefits of preventing a heart attack against the personalized risk of muscle disorders.

"Treatment decisions are often based on estimates of a person's future cardiovascular risk, but much less information is available about their individual risk of adverse outcomes."

Professor James Sheppard, Professor of Primary Care Research at the University of Oxford, via phc.ox.ac.uk

Professor Constantinos Koshiaris, Assistant Professor of Medical Statistics at the University of Nicosia Medical School, added that understanding potential harms is as important as estimating benefit to support balanced discussions about treatment options.

The tool is available via the Oxford University Innovation software store as the STRATIFY-StatinMD Risk Calculator for academic use.