Sleep Disturbance in Psoriatic Disease: Prevalence and Associated Factors

Objective. We aimed to determine the prevalence and quality of sleep in patients with psoriatic arthritis (PsA) and those with psoriasis without PsA (PsC) followed in the same center, to identify factors associated with sleep disturbance, and to compare findings to those of healthy controls (HC). Methods. The study included 113 PsA [ClASsification for Psoriatic ARthritis (CASPAR) criteria] and 62 PsC (PsA excluded by a rheumatologist) patients and 52 HC. Clinical variables were collected using a standard protocol. The sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Other patient-reported outcomes collected included the Health Assessment Questionnaire (HAQ), Dermatology Life Quality Index, EQ-5D, Medical Outcomes Study Short Form-36 survey, patient’s global assessment, and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-fatigue) scale. Statistical analyses included descriptive statistics, Wilcoxon rank-sum test, and linear regression. Results. The prevalence of poor sleep quality was 84%, 69%, and 50% in PsA, PsC, and HC, respectively. Total PSQI score was higher in both patients with PsA and patients with PsC compared with HC (p < 0.01) and higher in patients with PsA compared to patients with PsC (p < 0.0001). EQ-5D anxiety component, EQ-5D final, and FACIT-fatigue were independently associated with worse PSQI in patients with PsC and those with PsA (p < 0.05). Actively inflamed (tender or swollen) joints are independently associated with worse PSQI in patients with PsA (p < 0.01). Conclusion. Patients with psoriatic disease have poor sleep quality. Poor sleep is associated with fatigue, anxiety, and lower EQ-5D. In patients with PsA, poor sleep is associated with active joint inflammation.