Comorbidities, pain and fatigue in psoriatic arthritis, psoriasis and healthy controls: a clinical cohort study

Objectives. To explore the prognostic value of pre-specified comorbidities on treatment outcomes in PsA, and to compare baseline data with cutaneous psoriasis without arthritis and healthy controls (HC). Methods. Patients initiating conventional synthetic/biological disease-modifying antirheumatic drugs were enrolled in this clinical observational cohort study, and data on comorbidities, and clinical and patient-reported outcomes were retrieved at baseline and after 4 months. Pearson's chi-squared tests were performed to investigate the prognostic value of pre-specified comorbidities and achievement of ACR20, DAPSA50 and MDA. Mann-Whitney U tests were used to compare OMERACT PsA Core Outcome Set (COS) measures at baseline and follow-up for the pre-specified comorbidities. Results. A total of 100 PsA patients were included at baseline. Statistically significantly fewer patients with obesity achieved DAPSA50 compared with patients without obesity (P = 0.035), and fewer patients with hypertension (P = 0.034) and Charlson Comorbidity Index (CCI) >= 1 (P = 0.027), respectively, achieved MDA compared with patients without these comorbidities. Patients with obesity, hypertension, widespread pain, and CCI >= 1 had significantly worse COS measures at follow-up compared with patients without these comorbidities. At baseline, patients with PsA had higher disease burden compared with patients with cutaneous psoriasis and HC, including higher pain (P<0.001) and fatigue (P<0.001) scores, and more widespread pain (P = 0.002). Conclusion. Obesity, hypertension and CCI >= 1 were prognostic factors for poorer treatment outcome rates in PsA. Pain and fatigue were more frequently reported among patients with PsA compared with patients with cutaneous psoriasis and HC.