PO:13:189 | Greater impact of psoriatic arthritis in females: is this mediated primarily by disease activity?

Roberta Masnata¹, Valentina Boni¹, Giusy Peluso¹, Giulia Calabrese¹, Enrico De Lorenzis¹, Gerlando Natalello¹, Maria Antonietta D'Agostino¹, Augusta Ortolan¹. | ¹UOC Reumatologia e Immunologia Clinica- Fondazione Policlinico Agostino Gemelli IRCCS-Università Cattolica Sacro Cuore, Roma, Italy.

Background. Sex-related differences have been observed in psoriatic arthritis (PsA), with women often reporting a higher disease burden. Previous studies suggest that female patients experience more pain, fatigue, and reduced quality of life. However, it remains unclear whether this increased disease impact is primarily mediated by disease activity. Objective To evaluate whether the higher disease impact (measured by PSAID) observed in female patients with PsA is mediated by disease activity (measured by DAPSA).

Methods. A cross-sectional study was conducted on consecutive patients who met CASPAR criteria for PsA. Demographic, clinical, and lifestyle information was collected, including socio-economic characteristics and comorbidities (with a focus on fibromyalgia). Disease activity was assessed using the Disease Activity index for Psoriatic Arthritis (DAPSA), and disease impact was measured using the Psoriatic Arthritis Impact of Disease (PSAID) questionnaire. Comparisons between males and females were performed using Mann-Whitney U or Chi-square tests. Mediation analysis was conducted following the Baron and Kenny approach, testing the significance of each association across three linear regression models: (1) total effect of sex on PSAID; (2) effect of sex on DAPSA; and (3) effect of DAPSA on PSAID adjusted for sex (Figure). All models were adjusted for age, BMI, comorbidity index (RDCI), and fibromyalgia. Results were expressed as beta (95% confidence interval).

Results. A total of 136 PsA patients were included (54% female; mean age 58.9±12.0 years). The characteristics of female and male patients are displayed in Table. No major differences in disease manifestations were observed between sexes. Fybromialgia was more frequent in males. Females consistently reported higher scores in patient-reported outcomes, including DAPSA components related to pain and global disease activity, and across all PSAID items. In multivariable analysis, all associations required for mediation were significant: male sex was associated with lower PSAID scores ( = -1.73, 95% CI: -2.60 to -0.85) and lower DAPSA scores ( = -2.89, 95% CI: -5.57 to -0.22), while DAPSA was positively associated with PSAID ( = 0.20, 95% CI: 0.15 to 0.25), supporting a mediating role of DAPSA. However, the indirect effect through DAPSA accounted for 33% of the total effect of sex on PSAID, indicating partial mediation.

Conclusions. Disease activity explains only part of the higher disease impact experienced by female PsA patients. Additional contributor, such as altered pain perception, fibromyalgia, and possibly psychosocial or cultural factor, may significantly influence disease burden. These findings underscore the need for individualized, sex-aware management strategies and further research into non-inflammatory drivers of disease impact in PsA.