Statins may decrease mortality in patients with ankylosing spondylitis or psoriatic arthritis

Treatment with statins may reduce mortality risk among patients with ankylosing spondylitis or psoriatic arthritis, according to findings presented during the plenary session at the American College of Rheumatology Annual Meeting.

“We know that systemic inflammation is a risk factor for cardiovascular disease,” Beth Laurie Jonas, MD, FACR, told Healio Rheumatology. “A very interesting paper examined whether the use of statins may decrease mortality in patients with ankylosing spondylitis and psoriatic arthritis.”

The incident user cohort study was presented by Amar Oza, MD, of Massachusetts General Hospital. Oza and colleagues identified patients with ankylosing spondylitis or psoriatic arthritis who had initiated statins from a general United Kingdom population database (n = 2,904). Data was collected between January 1, 2000 and December 31, 2014.

Patients with ankylosing spondylitis or psoriatic arthritis who initiated statins were compared with 2,904 propensity-matched comparators with ankylosing spondylitis or psoriatic arthritis who did not begin statins. Propensity score-matched cohorts of those who initiated statins and those who did not were compared within 1-year cohort accrual blocks to account for potential confounders, according to the study results. The researchers utilized 50 variables to create propensity scores, including disease duration, socioeconomic status, BMI, lifestyle factors and medication use, among others.

“In an effort to balance the distribution of confounders between groups, we utilized propensity score matching,” Oza said. “The function of this process is to assign a score to the probability of receiving a treatment as a function of the confounders.”

Over a mean follow-up of 5.3 years, 271 patients taking statins died, compared with 376 individuals not prescribed statins during a mean follow-up period of 5.15 years. This corresponds to incidence rates of 17.62/1,000 and 25.14/1,000 person-years, respectively, according to the study results. Statin initiation was associated with a 33% reduction in all-cause mortality (HR = 0.68, 95% CI, 0.57-0.81).

The unmatched cohorts were compared to evaluate the effectiveness of the researchers’ propensity score matching. In this comparison, patients who initiated statins (n = 3,389) had a 44% higher risk of mortality (HR = 1.44; 95% CI, 1.22-1.70) than those who did not begin statins (n = 3,389) because of “confounding by indication,” according to the study results.

“In this large, community-based cohort, patients with ankylosing spondylitis or psoriatic arthritis were less likely to die if they had been started on a statin,” Jonas told Healio Rheumatology. “They used a very interesting construct to try to correct for many of the comorbidities and other variables in this cohort. There’s certainly a lot more to be done in this area, but this gives us some data and some direction about where to go in future studies.” – by Julia Ernst, MS

Reference:

Oza A, et al. Abstract 910. Presented at: The American College of Rheumatology Annual Meeting; Nov. 11-16, 2016. Washington.

Disclosures: Jonas and Oza report no relevant financial disclosures.