ASSESSMENT OF SEASONAL VARIATIONS ON CHRONIC INFLAMMATORY RHEUMATISMS ACTIVITY

Background: Although rheumatoid arthritis (RA) and spondyloarthritis (SA) activities have been described to vary under the influence of several factors, little is known about the influence of seasonality on the activity of chronic inflammatory rheumatisms. Objectives: To assess the influence of seasonality on the activity of chronic inflammatory rheumatisms. Methods: We conducted a cross-sectional study involving patients with RA (2010 ACR/EULAR criteria) and SA (2009 ASAS criteria). Chronic inflammatory rheumatisms activity was assessed during the summer (June-September) and winter (December-February) using clinical parameters including the Patient’s Global Assessment of disease activity (PGA), 10-cm Visual Analog Scale (VAS) pain score, morning stiffness, nocturnal awakenings, and joint count for RA (tender joint count (TJC) and swollen joint count (SJC)); biological parameters including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); disease activity scores including the SDAI, CDAI and DAS 28 for RA, BASDAI and ASDAS CRP for SA. An analysis of variance (ANOVA) was used to assess the statistical relationship between seasonality and rheumatisms activities. Results: We enrolled 175 patients (100 RA and 75 SA) with a sex ratio of 0.5 and a mean age of 57.75 ± 10.53 years [23-83]. The mean chronic inflammatory rheumatisms duration was 12.38 ± 4.6 years. RA was erosive in 91% of cases. Rheumatoid factor and anti-citrullinated peptides antibodies were positive respectively in 84% and 85% of cases. Seventy-five percent of RA patients were on corticosteroids with a mean dose of 10.14 mg/day of prednisone equivalent and 79% of SA patients were on non-steroidal anti-inflammatory drugs. Eighty percent of our patients were treated with conventional synthetic DMARD and 44% with biological DMARD. Small joints were more affected than large joints regardless of the season in RA patients (p=0.05). The following parameters were higher in winter than in summer in RA patients: mean PGA 4.73 vs 4.64 (p=0.01); mean morning stiffness 1.6 vs 1.1 (p=0.01); mean SJC 8.7 vs 7.5 (p=0.01); mean DAS 28 ESR 4.56 vs 3.99 (p= 0.05); mean DAS28 CRP 4.6 vs 3.41 (p= 0.05), mean SDAI 21.8 vs 19.5 (p= 0.05); mean CDAI 20.5 vs 18.75 (p= 0.01) and mean ESR 45.6mm/h vs 38.2 mm/h (p=0.01). As for SA, the following parameters were higher in winter than in summer: mean morning stiffness 2 vs 1.4 (p= 0.01); mean ASDASCRP 3.9 vs 3.1 (p= 0.01) and mean BASDAI 6.2 vs 4.9 (p= 0.05). However, we found no statistically significant correlation between seasonal changes and VAS pain score, nocturnal awakenings, TJC, and CRP. Conclusion: Chronic inflammatory rheumatisms activity was higher in winter. Health care professionals should take seasonal changes into account in order to improve therapeutic care. Disclosure of Interests: None declared Citation: Ann Rheum Dis, volume 80, supplement 1, year 2021, page 1466Session: HPR Patients’ perspectives, functioning and health (descriptive: qualitative or quantitative) (Publication Only)