Chinese registry of rheumatoid arthritis (CREDIT) V: sex impacts rheumatoid arthritis in Chinese patients

Background: The impact of sex on the clinical manifestations of rheumatoid arthritis (RA) were diversely reported in the literature. The Chinese Registry of rhEumatoiD arthrITis provides a platform for the investigation of this issue in Chinese patients.Methods: Demographic and clinical parameters were collected from all enrolled patients with RA and from patients with early RA (disease duration ≤6 months). The differences in data regarding disease activity, comorbidities, and medications for RA were compared between men and women. The proportions of patients who achieved remission and low disease activity were compared at enrollment and during 3-, 6-, and 12-month follow-up visits.Results: A total of 11,564 patients were enrolled, 83.6% of whom were female. In all the enrolled patients and patients with early RA, C-reactive protein (CRP, 12.0vs. 6.7 mg/L), pain visual analogue scale (4.8vs. 4.5), patient’s and physician’s global assessment (4.9vs. 4.5 and 4.9vs. 4.5), 28-joint disease activity score using DAS28-CRP (4.3vs. 4.0) simplified disease activity index (21.9vs. 19.9), and clinical disease activity index (19.3vs. 18.0) were significantly higher in men than in women. Additionally, the swollen joint count/tender joint count and DAS28 using erythrocyte sedimentation rate were higher in male patients than in female patients with early RA. More female patients with early RA reached the treatment target at baseline than male patients (23.4%vs. 18.2%, assessed by CDAI). At 3 months, 6 months, and 12 months, the proportion of remission and treatment target achievement was similar in both sexes. Coronary artery disease (CAD) and stroke were more frequent in men than in women.Conclusions: In Chinese patients with RA, men were found to have more active disease, as well as more cases of CAD and stroke. Therefore, sex should be carefully considered during the personalization of RA treatment.