Study Finds Atorvastatin Ineffective for Knee Osteoarthritis Treatment

Professor Flavia Cucuttini (Medical Journal of Australia)

The use of atorvastatin in treatment of symptomatic knee osteoarthritis (OA) did not significantly reduce cartilage volume loss in a recent study. 

Over a two-year period, once-daily 40mg atorvastatin did not significantly reduce the rate of tibial cartilage volume loss nor improve knee pain versus placebo, according to new data. 

Investigators led by Professor Flavia Cicuttini of the School of Public Health and Preventive Medicine at Monash University in Australia, conducted a randomized, double-blind, placebo-controlled trial from August 2013 to April 2016.

Trial participants were required to have symptomatic knee OA for at least 6 months, meet a pain score of >20mm on a 100mm visual scale and match American College of Rheumatology (ACR) clinical criteria. Patients were recruited through advertising and on a practitioner basis.

Of the trial participants, 459 patients were screened and 304 were randomized from the screening. Participants in the trial either received atorvastatin (n = 151) or the placebo (n = 153).

Investigators took MRIs of the knee at both baseline and at the 24-month marker. They also measured elements at baseline and follow-up using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for knee pain (0-500), stiffness (0 – 200) and function (0 – 1700). 

A minority of participants withdrew from the study, including 32 in the atorvastatin group and 24 in the placebo group, leaving investigators with 248 participants completing the study.

Participants had a mean age of 55.7 years and a majority of participants were women (169).

Baseline characteristics show a higher proportion of females in the atorvastatin group compared to the placebo. At the end of the study, 84.6% participants complied with the study medication of >80% based on pill count.

Data showed that tibial cartilage volume reduced by a mean value of 1.66% in the atorvastatin group and 2.17% in the placebo group over 2 years.

Both groups also experienced a mean improvement in knee pain, stiffness and function over the 2 years of study, but there was no significant statistical difference measured at any time point. 

The team monitored adverse events at the conclusion of the trial and found 89 adverse events in the atorvastatin group, with 37.7% of participants experiencing ≥1 event. In the placebo group, there were 82 adverse events, with 34% of participants experiencing ≥1. 

However, the investigators do not believe the adverse events were related to the treatment.

Previous observational studies found statin use was not associated with the incidence or progression of knee OA, with analysis showing reduced risk of knee OA. The randomized controlled study in this investigation did not support a beneficial effect of atorvastatin.

However, in a sub-group analysis, investigators found evidence that atorvastatin may help reduce the development of bone marrow lesions and cartilage loss in patients without lesions at baseline or in different phenotypes of knee OA.

“We cannot exclude an effect of atorvastatin on reducing cartilage volume loss in those without bone marrow lesions,” investigators wrote. “The widespread use of statins in the community for the prevention of cardiovascular disease may have a collateral benefit, reducing the structural progression of knee OA.”

The team concluded that while further study is necessary, their research does not support the use of atorvastatin in reducing knee cartilage volume loss.

“These findings do not support the use of atorvastatin in the treatment of knee OA,” investigators wrote. “However, based on the findings from the subgroup analysis, it may be that widespread use of statins in the management of cardiovascular disease has some benefit on reducing the progression of knee OA, and this is worthy of further targeted study.”

The study, “Effect of atorvastatin on knee cartilage volume in patients with symptomatic knee osteoarthritis: results from a randomized placebo‐controlled trial” was published online in Arthritis & Rheumatology.