REDUCED SLEEP QUALITY AND DECREASED EXECUTIVE PERFORMANCE IN PATIENTS WITH PSORIASIS

Introduction: Psoriasis is a widespread dermatological disease with frequent multiple comorbidities. In its pathogenesis and maintenance, sleep impairments seem to play a crucial, albeit underestimated, role. Here, our main aim is to provide an in-depth analysis of psoriatic patients’ objective sleep features - whose clear and full description is still lacking - also addressing their association with cognitive functioning. Materials and methods: Psoriatic patients were recruited from Dermatology Units based on the following criteria: 18–65 years, mild symptom severity (PASI< 10; DLQI< 5), no systemic treatment (topical only), absence of comorbid medical conditions (including psychiatric and sleep disorder diagnoses), no history of drug or alcohol abuse, limited caffeine (no more than 150 mg/day) and alcohol (no more than 250 mL/day) consumption. Control participants were recruited via social media and advertisements following the same inclusion criteria except for the presence of psoriasis. All participants underwent 7 days of actigraphy (Camtech, UK). Sleep during the final two nights was also monitored using SomnoArt (PPRS, FR), a validated wearable device. Cognitive performance was assessed with the Rey-Osterrieth test, Rey Auditory Verbal Learning Test (RAVLT), Finger Tapping Test (FTT), 2-back test, and Go/No-Go task. Results: Nineteen patients (12M, 7F; age = 37.89±12.93) and 53 controls (14M, 39F; age = 28.33± 13.29) were recruited. Psoriatic patients showed reduced total sleep time (p=.013), higher sleep latency (p=.023), NREM (p=.050) and REM sleep duration (p=.024) compared to control participants. In addition, patients’ sleep showed reduced number of sleep cycles (p=.041) and frequency of short awakenings (< 2 minutes; p=.049), as well as a higher number (p=.005) and frequency (per hour of sleep) (p=.003) of functional uncertainty periods (FUP; i.e. periods with three or more state transitions, separated by no more than 90 seconds). As for the cognitive assessment, patients committed more errors on the Go/No-Go Task (p=.041), obtained higher scores at the Rey Figure immediate test (p=.004) and less correct responses on the 2-back test (p=.043). In the overall sample, positive correlations emerged between sleep efficiency and the number of correct responses on the FTT (ρ=.353; p=.003) and total responses to the 2-back test (ρ=.242; p=.042). Sleep cycle number correlated positively with performance at the Rey Figure Delayed Recall (ρ=.301; p=.011) and RAVLT (ρ=.257, p=.012) and negatively with Go/No-Go response time (ρ=-.338; p=.004). Conclusions: Despite the mildness of symptom severity, psoriatic patients display significant impairments in their sleep features. Specifically, patients’ sleep turns out to be shorter and more fragmented and notably shows reduced organization in NREM-REM cycles, a well-established indicator of sleep quality. Psoriatic patients’ sleep also appears less stable than controls, as reflected by data on FUPs. These changes are negatively correlated with performance at executive tasks, highlighting an interesting interplay between sleep and cognitive functioning. The present data suggest that specific interventions to improve sleep quality could have an impact on patients’ psychophysiological state and even on the very same course of psoriatic disease. Funded by the European Union – Next Generation EU, Mission 4 Component 1 CUP B53D23003440006