Background: Ultrasound (US) can improve disease activity assessment in psoriatic arthritis (PsA). Despite known associations of various factors with US abnormalities, their significance in PsA is unclear. This gap in understanding underscores the need for deeper investigation into how these factors interplay with sonographic findings in PsA.

Objective: The main goal is to investigate the impact of contextual factors on sonographic lesions in patients with active PsA.

Methods: In a cross-sectional study, active PsA patients underwent US evaluation for inflammatory (inf) and structural (str) lesions like synovitis, enthesitis, peritenonitis (PTI), tenosynovitis (TN), bone erosion (BE), and new bone formation (NBF), with semi-quantitative B-mode and Dopper scores. The US protocol included 64 joints, 16 entheses, and 24 tendons. Total summary scores for each domain were analyzed using t-tests and linear multivariable regression by age (≥60, <60), sex, body mass index (BMI) (≥30, <30), diabetes, alcohol (any, none), smoking, disease duration (≥1, <1 years), and biological/target-synthetic disease-modifying anti-rheumatic drug (b/tsDMARDs) exposure.

Results: In the study of 115 patients (mean age 47.1, 47.8% females), the average Disease Activity in PSoriatic Arthritis was 22.6, with mean US score of 35.6 for synovitis and 30.1 for total enthesitis. Significantly higher sonographic inf and str enthesitis, BE, and NBF scores were found in age ≥ 60 group (Figure 1). Synovitis and TN scores were significantly higher in b/tsDMARDs-exposed patients. Diabetics had higher str enthesitis but lower BE scores. Other groups showed no significant differences.

Multivariable analysis (Figure 2) revealed that age ≥ 60 was independently associated with higher inf and str enthesitis (adjusted β 6.37 and 14.6,

respectively, p < 0.05). b/tsDMARDs-exposure correlated with higher synovitis and TN scores (adjusted β 12.8 and 5.95, respectively, p < 0.05). Age ≥ 60 (adjusted β 2.53), male sex (adjusted β 1.58), BMI ≥ 30 (adjusted β -1.72), and diabetes (adjusted β -3.76) were significantly associated with BE score, with age also being associated with NBF (adjusted β 13.7, p < 0.001).

Conclusion: Older age consistently correlated with more severe inf and str US lesions, suggesting an association between age and more severe PsA phenotype or overlap with age-related joint abnormalities like osteoarthritis. The higher synovitis and TN scores in b/tsDMARDs-exposed patient suggests its role as a severity marker. These findings highlight the importance of integrating patient demographics and treatment history in PsA sonographic assessments, offering insights for more personalized management strategies.