P273 Factors related to insomnia in patients with psoriatic arthritis: a cross-sectional study
Authors: McGagh Dylan , McGowan Niall M , Elahi Shezan , MacDonald Joanne , Saunders Kate E. A , Coates Laura C 
Published: April 2022

Abstract

Background/Aims
Several studies have demonstrated an increased prevalence of sleep disorders in patients with psoriatic arthritis (PsA). However, there are few data on the relationship between sleep disturbance and disease activity in PsA. We conducted a cross-sectional study to investigate the prevalence of insomnia symptoms and poor sleep quality in PsA and examine correlation with demographic, clinical and patient-reported outcome measures.

Methods
Patients were recruited from rheumatology clinics at a single centre. Patients had a diagnosis of PsA, met the CASPAR (ClASsification criteria for Psoriatic ARthritis) criteria and were aged ≥ 18 and ≤ 80 years. They had no other confirmed sleep disorder diagnoses. Disease activity was calculated using the cDAPSA (Clinical Disease Activity in PSoriatic Arthritis) score. Disease impact was measured using a pain visual analogue scale (VAS) and the Psoriatic Arthritis Impact of Disease (PsAID)-12 questionnaire and functional impairment was assessed using the health assessment questionnaire (HAQ). We used the Sleep Condition Indicator (SCI) to assess symptoms of Diagnostic and Statistical Manual of Mental Disorders (DSM)-V insomnia disorder (ID). The SCI is a score from 0-30 with lower scores indicating worse subjective sleep. We used the Pittsburgh Sleep Quality Index (PSQI) to assess subjective sleep quality. Relationships between clinical characteristics and sleep disturbance were examined using Pearson’s correlation coefficients and multivariable logistic regression.

Results
Thirty participants were enrolled in the study, of which 13 were female. Mean (SD) age of participants was 49 (13.5) years. Overall, the prevalence of probable DSM-V ID (SCI score ≤ 16) was 43.33% (13/30) with a mean (SD) SCI score of 6.80 (4.79). Mean (SD) PSQI score was 6.77 (3.22) with 60% (18/30) classified as subjective poor sleepers. Mean (SD) pain VAS, PsAID-12 and HAQ were 33.89 (28.67), 2.97 (2.05) and 46.12 (38.83), respectively. Mean (SD) cDAPSA score was 12.3 (15). A significant correlation was observed between the SCI score and cDAPSA (r=-0.3809, p = 0.038), and SCI and PsAID-12 scores (r=-0.3809, p = 0.033). No correlation was found between SCI score and HAQ, age, pain VAS, or disease duration. Multivariable logistic regression controlling for age found an association between cDAPSA and probable ID (OR:1.098 95%CI:1.014-1.253). This association did not persist once pain level, gender, PsAID-12 and HAQ scores were controlled for.

Conclusion
This cross-sectional analysis of patients with PsA demonstrates that sleep disturbance is highly prevalent. Symptoms of insomnia in this small cohort were related to higher baseline disease activity and self-reported disease impact. This study is the first to demonstrate these findings and warrants further exploration in a larger sample size with longitudinal data. It would be of interest to understand the relationship between insomnia and disease activity and whether insomnia is responsive to treating PsA to low disease activity levels.

Disclosure
D. McGagh: None. N.M. McGowan: None. S. Elahi: None. J. MacDonald: None. K.E.A. Saunders: None. L.C. Coates: None.