Patients with ankylosing spondylitis or psoriatic arthritis who take statins may have as much as a 33 percent lower mortality risk, according to new research findings presented this week at the American College of Rheumatology Annual Scientific Meeting in Washington.

Ankylosing spondylitis (AS) is arthritis of the spine that can resemble rheumatoid arthritis. It more often affects males, with HLA antigen present but rheumatoid factor absent. Psoriatic arthritis (PsA) is a chronic form of arthritis that can affect the skin and joints. It can lead to joint damage if not treated.

Researchers at Massachusetts General Hospital in Boston set out to explore the potential benefits of statins, which can both lower lipids and reduce inflammation, in patients with AS or PsA, which are both seronegative spondyloarthropathies. Both AS and PsA are associated with increased cardiovascular mortality risk. The goal of the study was to see if initiation of statins might be associated with a lower mortality risk in this patient population.

"The expanding literature on the dual-role of statins to lower both inflammation and cholesterol levels has naturally led to interest in the role of statins in inflammatory arthritis," said Amar Oza, MD, a rheumatologist at Massachusetts General and a lead author of the study along with Na Lu, MD and Hyon Choi, MD. "A randomized trial found such a dual benefit among patients with rheumatoid arthritis (RA), and a population-based study of patients with RA found a survival benefit associated with statin use as well. As such, we hoped to quantify the potential impact of statins in the seronegative spondyloarthropathies, as the risk of all-cause mortality and even cardiovascular-specific mortality has shown to be elevated in these conditions."

Using a United Kingdom (UK) general population database, the researchers studied both AS and PsA patients between January 1, 2000 and December 31, 2014. They also used 50 different variables to create propensity scores, including disease duration, socioeconomic status, body-mass index, lifestyle factors and medication use. Of 2,904 patients with either AS or PsA who started statins, 271 died during the follow-up, a mean of 5.3 years. Of 2,904 propensity-matched AS or PsA patients who did not start statins, 376 died during the follow-up, a mean of 5.15 years. Baseline characteristics between the two groups were well balanced. Statin initiation was associated with 33 percent reduction in all-cause mortality.

The inverse association of statin initiation and mortality risk among AS and PsA patients appears to be larger than that observed in other population-based cohort studies of rheumatoid arthritis patients, the study noted. Statins' dual benefits of lowering lipids and reducing inflammation, both contributors to cardiovascular disease risk, could be the reason for this significant benefit.

"Given the increased risk of mortality and cardiovascular disease compared to the general population, patients with seronegative spondyloarthropathies like AS and PsA may benefit from the dual anti-inflammatory and lipid-lowering properties of statins, perhaps even more than in the general population," said Dr. Oza. "This observational study raises the possibility that clinicians may have a lower threshold for starting their patients on statins to mitigate this mortality risk. To that effect, it sets the groundwork for potential clinical trials to come, which will provide high-level evidence about the impact statins have on their health."

More research is needed to explore the potential benefits of statins to prevent mortality due to cardiovascular and other causes, he concluded.

This research was supported by funding from the NIH's National Institute of Arthritis and Musculoskeletal and Skin Diseases.