Restless Legs Syndrome in Patients with Psoriatic Arthritis: Association with Inflammatory and Clinical Parameters...

Introduction/Objectives: Restless legs syndrome (RLS), a chronic neurological disorder related to brain iron metabolism, has been linked to immune-mediated inflammatory conditions such as psoriatic arthritis (PsA). However, the role that inflammation plays in this association and the impact of RLS on PsA outcomes remain unclear. This study aims to investigate the association between RLS and inflammatory/clinical parameters in PsA patients. Materials and Methods: In this cross-sectional study, 230 PsA patients completed the International Restless Legs Syndrome Study Group (IRLSSG) screening questionnaire, with diagnoses confirmed by a neurologist. Data collected included clinical features, disease activity, and comorbidities (obesity, anxiety, depression, insomnia, and fibromyalgia). Results: In total, forty-six patients met the IRLSSG criteria (20%). Those with RLS more frequently had polyarthritis (27% vs. 6%; p < 0.001), more swollen joints (2.0 vs. 1.4; p = 0.04), greater psoriatic involvement (5.7 vs. 3.6; p < 0.001), greater fatigue (39.0 vs. 30.5; p < 0.001), and greater disease activity (14.5 vs. 10.5; p < 0.001). They also exhibited increased disease impact (4.7 vs. 2.9; p < 0.001), poorer functioning (0.7 vs. 0.5; p = 0.01), and higher levels of anxiety (8.0 vs. 5.5; p < 0.001), depression (6.5 vs. 3.9; p < 0.001), and sleep disturbance (13.9 vs. 8.7; p < 0.001). Skin lesions and polyarthritis explained nearly 40% of RLS cases (Odds Ratio (OR) 1.4; 95% Confidence Interval (CI) 1.03-2.0; p = 0.03 and OR 1.03; 95% CI 1.00-1.9; p = 0.04). Conclusions: Psoriatic activity and inflammation may contribute to RLS in PsA. The coexistence of RLS was associated with greater disease activity, greater disease impact, and more emotional and sleep-related comorbidities.