Clinical characteristics of obese patients with adult-onset Still's disease. Data from a large multicentre cohort

Objectives: To evaluate the impact of obesity in patients with adult-onset Still's disease (AOSD) and to assess their clinical characteristics and disease outcomes. Methods: The clinical features of AOSD patients with a body mass index (BMI) ≥ 30 were assessed among those included in the multicentre Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale (GIRRCS) cohort. Results: Out of 139 AOSD patients, who had BMI registered in our database, 26 (18.7%) had a BMI ≥ 30. A lower rate of sore throat (P < 0.05), pericarditis (P < 0.05), and pleuritis (P < 0.05) was shown in obese patients. Additionally, obese patients showed higher values of C-reactive protein (CRP) (P < 0.05) and ferritin (P < 0.05) than others. Furthermore, obese patients were characterised by biologic disease-modifying antirheumatic drug (bDMARD) failure in subsequent follow-up (P < 0.05). They also presented higher rate of comorbidity than non-obese patients (P < 0.05). Finally, obesity predicted the presence of a chronic disease course in both univariate (HR: 1.72, 95%CI: 1.03–2.51, P < 0.05) and multivariate analyses (HR: 1.85, 95%CI: 1.45–2.89, P < 0.05). Obesity was also a significant predictor of bDMARD failure in AOSD patients in both univariate (HR: 3.03, 95%CI: 1.42–6.45, P < 0.01) and multivariate analyses (HR: 3.59, 95%CI: 1.55–8.27, P < 0.01). Conclusion: Obese patients at the time of diagnosis of the disease were characterised by a lower prevalence of sore throat, serositis, as well as by higher values of CRP and ferritin. Obesity was also a predictive factor for a chronic disease course and bDMARD failure, thus highlighting a subset of patients with AOSD to be carefully managed.