As life expectancy increases, psoriatic arthritis (PsA) in older individuals becomes more prevalent. We explored whether late-onset versus earlier-onset PsA patients display different clinical features at diagnosis and/or during the disease course, as well as different treatment approaches and comorbidity profiles. We retrospectively collected data from consecutive PsA patients attending two rheumatology centers (December 2017-December 2022). Late-onset PsA patients (diagnosis-age: ≥60 years) were compared to those diagnosed before 60 years old. Univariate analyses and logistic regression were performed to examine for factors associated with late-onset PsA. For sensitivity analyses, the cohort's mean diagnosis age was used as the cut-off value. Overall, 281 PsA patients were included (mean ± SD diagnosis-age: 46.0 ± 13.3 years). Of them, 14.2% (N = 40) had late-onset PsA. At diagnosis, after controlling for confounders, no demographic and clinical differences were identified. During the disease course, the late-onset group exhibited 65% fewer odds of manifesting enthesitis (adjusted Odds-ratio-adOR 0.35; 95% confidence interval 0.13-0.97), but higher frequency of dyslipidemia (adOR 3.01; 1.30-6.95) and of major adverse cardiovascular events (adOR 4.30; 1.42-12.98) compared to earlier-onset PsA group. No differences were found in the treatment approaches. In sensitivity analyses, PsA patients diagnosed after 46 (vs. ≤46) years old had an increased frequency of hypertension (adOR 3.18; 1.70-5.94) and dyslipidemia (adOR 2.17; 1.25-3.74). The present study underpins that late-onset PsA is not uncommon, while the age at PsA onset may affect the longitudinal clinical expression of the disease. Patients with late-onset PsA were less likely to manifest enthesitis but displayed increased cardiovascular risk.
Keywords: characteristics; early-onset; late-onset; psoriatic arthritis.