Sex-related differences in clinical characteristics and comorbidities and their impact on clinical outcome in Korean patients with rheumatoid arthritis

Abstract

Backgrounds: Rheumatoid arthritis (RA) is more prevalent in women and prior studies have reported several epidemiologic differences between sex and low achievement of remission in women RA. However, these sex differences across various populations remain incompletely understood. This study aimed to elucidate sex-related differences in clinical characteristics and their potential impact on clinical outcome in a large Korean cohort of patients with RA. Methods In total, 5,376 RA patients from the KORean Observational study Network for Arthritis (KORONA) database were examined at baseline and for 3 consecutive years using the disease activity score 28 (DAS28), health assessment questionnaire (HAQ), and health-related outcomes. Within a subgroup with active disease (DAS28 ≥ 3.2) at baseline, sex impacts on clinical outcome during a 3-year period were analyzed using generalized estimating equation (GEE) models. The sex effect on achieving clinical remission was analyzed using Cox-proportional hazard regression. Results At baseline, women (n = 4,574) were younger and had more erosive disease and longer disease duration than men (n = 802) with significantly higher scores in DAS28, HAQ, and patient-reported outcomes. The prevalence of interstitial lung disease, cardiovascular disease, and diabetes in men was significantly higher than that of women. In a RA subgroup with active disease at baseline, a GEE analysis demonstrated that sex significantly influenced the rate of change of DAS28 (p = 0.035) over time. In that group, men are associated with achieving DAS28 sustained remission as well as point remission (both p < 0.001). Conclusion Most comorbidities were more prevalent in men than in women among Korean patients with RA. However, for RA-related clinical outcomes, the longitudinal change in disease activity and the rate of achieving clinical remission were found to be worse in women RA. Therefore, sex-related differences should be considered when managing RA patients.