Age does not affect disease activity, management in ankylosing spondylitis

Markers of disease activity and treatment trends appear to be similar among geriatric patients with ankylosing spondylitis compared with younger counterparts with the same condition, according to findings presented at the American College of Rheumatology Annual Meeting.

“Ankylosing spondylitis in the geriatric population tends to be underrepresented in the literature,” Ahmed Omar, MD, of the University of Toronto, told Healio Rheumatology. “But the geriatric population is increasing worldwide. We need more research into this patient population.”

Omar and colleagues collected data from a longitudinal, Toronto-based cohort of patients with spondyloarthropathies. Geriatric patients were categorized as those at least 65 years of age and non-geriatric patients were those younger than 65 years. Data from a tertiary care orthopedics clinic in Toronto were used as an age-matched geriatric control group of patients without ankylosing spondylitis (AS).

“It is important to point out that this study did not aim to specifically look at ‘late onset AS,’” Omar said. “We aimed to develop a profile of patients who have AS and happen to be elderly, whether they developed the condition early or later in their lives.”

The investigators compared clinical and laboratory data between cohorts.

A total of 890 patients with AS were identified; 48 patients were classified as geriatric. The non-AS geriatric comparison group included 322 patients with knee osteoarthritis (OA).

Preliminary comparisons between young and geriatric patients with AS demonstrated no differences in gender distribution, although geriatric patients with AS tended to be older at the time of diagnosis (P < .001). The younger population was diagnosed earlier than the elderly group, which may reflect greater disease awareness among physicians in recent years, according to the study results.

No differences in clinical activity were observed between the groups, including mean inflammatory markers or Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores. Extra-articular manifestations were also similar between the geriatric and non-geriatric patients with AS.

No significant differences between the two groups were observed with regard to use of NSAIDs, disease-modifying antirheumatic drugs, corticosteroids and biologics, or in side effects associated with the agents. Investigators found 1% of patients in the geriatric group began biologic therapy at 65 years of age or older.

“Standard precautions regarding age-related pharmacokinetics still apply, but the results suggest it may not be necessary to avoid using certain immunomodulating agents in geriatric patients with AS,” Omar said. “In general, there may be a tendency to undertreat elderly patients due to concerns about drug-related side effects, but more research is required to better understand the way we can, and should, use these drugs in the elderly, as earlier trials tend to favor younger populations. Real-world, registry-based studies are a valuable resource that can help address some research questions, but we also need more prospective studies and clinical trials that cater to this specific age group.”

Mobility, as measured by the Bath Ankylosing Spondylitis Metrology Index (BASMI), and function, as measured by the Bath Ankylosing Spondylitis Functional Index (BASFI), were higher among geriatric patients with AS (BASMI, P < .001; BASFI, P < .04), indicating greater restricted spinal mobility and greater impact on function in the geriatric patient with AS. These patients were also more likely to have a history of physical trauma and/or injury (P = .03) and have a higher score on the SF-36 Health Survey. Quality of life scores were similar between groups.

There were more men in the group of patients with AS when the geriatric patients with AS and the geriatric patients with OA were compared. Patients without AS were more likely to smoke and have a history of diabetes (P = .04), as well as have greater functional disability scores. Rates of infection were similar between the groups.

“We show that geriatric patients with AS have similar treatment and disease activity parameters, but differ in a select few functional components and comorbidities when compared with the younger population,” the researchers wrote. “Further research into the geriatric AS population is needed to better define and manage this group’s specific needs.” – by Julia Ernst, MS

Reference:

Omar A, et al. Abstract 2755. Presented at: American College of Rheumatology Annual Meeting; Nov. 11-16, 2016; Washington.

Disclosure: The researchers report no relevant financial disclosures.