(B-298) Hormone Therapy and Risk of Psoriasis in Reproductive and Postmenopausal Women: A Target Trial Emulation

Background: Hormone therapy (HT) is commonly prescribed for contraception in the reproductive population and for managing menopausal symptoms in postmenopausal individuals. Beyond these uses, hormones are known to influence the immune system, skin cell functionality, and inflammatory responses, all of which play a role in psoriasis pathogenesis. Despite these connections, the impact of HT on psoriasis risk remains unclear, highlighting the need for further research across different age groups to inform clinical practice and optimize treatment strategies.

Objectives: To investigate the association between HT and the risk of psoriasis in reproductive-age and postmenopausal women.

Methods: This study employed a nationwide cohort design and target trial emulation using data from Taiwan's National Health Insurance Database (2001–2021). Women over 20 years old with no prior history of psoriasis, ovarian cancer, or breast cancer were included and categorized into reproductive-age (≤50 years) and postmenopausal (>50 years) groups. Those who initiated hormone therapy (HT) were designated as the exposed group, while those without HT served as the comparison group. The primary outcome was the incidence of psoriasis over a five-year period. To estimate hazard ratios (HRs), the study utilized inverse probability of treatment weighting (IPTW) and Cox proportional hazards models. Both intention-to-treat (ITT) and per-protocol (PP) analyses were conducted to strengthen the robustness of the findings.

Results: In the postmenopausal cohort, consisting of 1,482,302 HT users and 1,313,799 nonusers, the IPTW-adjusted HR for psoriasis in the ITT analysis was 1.48 (95% CI 1.44–1.52), while the PP analysis revealed a higher risk with an HR of 5.93 (95% CI 5.66–6.22). In the reproductive-age cohort, which included 3,849,721 HT users and 1,585,461 nonusers, the IPTW-adjusted HR in the ITT analysis was 1.93 (95% CI 1.90–1.99), with the PP analysis showing an even greater risk (HR 7.85, 95% CI 7.56–8.15). These results indicate a substantially increased risk of psoriasis associated with HT, particularly among younger women.

Conclusions: This study identifies a link between HT and an elevated risk of psoriasis in both reproductive-age and postmenopausal women. Clinicians should carefully assess the benefits and risks of HT and remain vigilant for early signs of psoriasis in patients.