Osteoporosis Prevalence in PsA Similar to General Population

Bianca Nogrady

January 07, 2021

The rates of osteopenia and osteoporosis among individuals with psoriatic arthritis are comparable to those seen in the general population, research suggests.

The cohort study, published in Arthritis Care & Research, also found that clinicians are likely to refer patients for bone mineral density (BMD) testing based on osteoporosis risk factors or psoriatic arthritis disease severity markers.

Timothy S.H. Kwok, MD, of the University of Toronto, and coauthors wrote that previous research suggested a possible link between psoriatic arthritis and osteoporosis or osteopenia. However, no cohort studies appear to have examined this association.

The study involved 201 individuals with psoriatic arthritis attending a single specialist clinic, who were enrolled in a longitudinal study of psoriatic arthritis (PsA) and who were also referred for BMD testing with dual-energy x-ray absorptiometry.

Of these participants, 13% had a BMD in the osteoporotic range, 45% were in the osteopenic range, and 42% were in the normal range for BMD. The prevalence of osteoporosis observed in the general population aged 50 or above, observed in an earlier large prospective study, ranged from 7% to 16%, and osteopenia ranged from 27% to 46%.

"Our study suggests that patients with PsA have similar BMDs compared to the general population," the authors wrote.

Researchers did note the suggestion that patients with polyarthritis had lower BMDs over time. Because of the small number of events, this did not achieve statistical significance, but "this relationship warrants further research, given that multiple cohort studies have independently demonstrated polyarticular onset of disease predicting clinical deformities and erosive disease in PsA," they wrote.

They also saw that patients with increased body mass index had a significant 21% lower odds of having a BMD in the osteoporotic range, while those using biologics had a significant 83% lower odds.

Among participants with BMD scores in the osteopenic or osteoporotic range, these scores were seen in the lumbar spine in 63% of measurements, the femoral neck in 88%, and the total hip in 39%. Mean T-scores for the lumbar spine were –0.30±0.32, and for the femoral neck were –1.10±1.04 and the total hip, –0.45±0.42.

The study also examined what factors were associated with referral for BMD testing. They found that increasing age, menopause, elevated acute phase reactants, or use of biologics, methotrexate, and systemic glucocorticoids were associated with a higher likelihood of undergoing BMD testing.

Noting that the latest Canadian clinical practice guidelines on BMD testing advise that age, menopause, and use of systemic glucocorticoids use are risk factors that should prompt testing, the authors suggested clinicians were using a combination of traditional osteoporosis risk factors and markers of psoriatic disease severity to underpin their decision to refer.

However, they commented that none of the factors associated with a higher likelihood of having a BMD test were actually associated with lower BMD scores.

"This suggests that clinicians may be over-screening patients with PsA for osteopenia/osteoporosis, as they do not appear to be at baseline higher risk for lower BMD scores than the general population," they wrote. "This is of importance, as there are currently no formal recommendations with regards to the optimal interval or time to commence BMD testing within the recent major PsA guidelines."

The study was supported by a grant from the Krembil Foundation. No conflicts of interest were declared.

SOURCE: Kwok TSH et al. Arthritis Care Res. 2020 Dec 16. doi: 10.1002/acr.24538.

This article originally appeared on MDedge.com, part of the Medscape Professional Network


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