The sex differences of rheumatoid arthritis symptoms and activities in China: A cross-sectional study of 3374 patients

Abstract

Abstract Background There are limited data studied the association between sex and rheumatoid arthritis (RA) symptoms and activities in China. Methods This is a cross-sectional study with recruitment of RA patients from 10 hospitals in China from 2014 to 2018. Patients were evaluated with the 28-joint Disease Activity Score based on erythrocyte sedimentation rate (DAS28-ESR), Simple Disease Activity Index (SDAI) for Rheumatoid Arthritis, Visual Analog Scale (VAS) scores, Revised American College of Rheumatology (ACR) Functional Classification of Global Functional Status, and vital signs. Mann-Whitney U and Chi-square tests were used to compare the sex differences. Ordinal logistic regression and linear regression models were used to estimate the odds ratio (OR) and adjusted for confounding factors of age and body mass index (BMI). Subgroup analyses were conducted to study the associations in RA patients with hypertension and diabetes. Results A total of 3374 RA patients were recruited. Ratio of female versus male was 4:1. After adjusting for age and BMI, significant sex differences were found in ACR functions, DAS28-ESR, SDAI, VAS, and C-reactive protein (CRP) levels. Patients with hypertension and diabetes accounted for 10% and 3% among all the RA patients, respectively. For RA patients with hypertension, significant association was found only between sex and CRP. Sex was not significantly associated with most clinical manifestations in diabetic RA patients except for level 2 of ACR functions of joints. Conclusion Our study provided epidemiological data of RA and its comorbidities in China. The results did not reach consensus to support substantial sex differences of RA symptoms and activities in Chinese populations.