Restless legs syndrome in patients with psoriasis: association with inflammation and sleep quality

Background We aimed to evaluate if psoriasis associated with restless legs syndrome (RLS) due to its close relationship with metabolic disorders. Methods This was a cross-sectional study in which the relationship between RLS and psoriasis was evaluated. Seventy consecutive psoriasis patients and 70 controls without any skin disorder were included in this study. Data including age, gender, body weight, height, and Psoriasis Area Severity Index (PASI) scores were recorded. Diagnosis of RLS was established using International RLS Study Group (IRLSSG) diagnostic criteria. International RLS Rating Scale (IRLSRS) was used to evaluate the severity of symptoms. Each participant completed forms of the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Dermatology Life Quality Index (DLQI). Results The RLS frequency in patients with psoriasis was 18.6% vs. 5.7% in the control group (P = 0.018). In psoriasis patients, BMI, DLQI, IRLSRS, hemoglobin, ferritin, CRP, and uric acid levels were significantly higher than those of the controls. In psoriasis patients with RLS, PASI, DLQI, PSQI, IRLSRS scores, CRP level, and BMI were significantly higher, and hemoglobin level was significantly lower relative to the psoriasis patients without RLS. PASI score was the sole independent associate of RLS presence in psoriasis patients. Conclusion Restless legs syndrome was significantly more common in psoriasis patients, and the presence of RLS was associated with significantly more severe psoriasis, more severe systemic inflammation, lower serum hemoglobin values, worse quality of life, and sleep quality.