The association between comorbidities and disease activity in patients with rheumatoid arthritis: a multicenter, cross-sectional cohort study in Japan with the highest proportion of elderly individuals

Abstract

Abstract Background This study aimed to assess the association of disease activity with the presence of comorbidities in patients with rheumatoid arthritis, using the Akita Orthopedic Group on Rheumatoid Arthritis (AORA) registry, a multicenter, cross-sectional registry in Japan with the highest proportion of elderly people. We included 1838 patients (mean age: 66.4 years old) who visited our affiliated institutions between April 2018 and March 2019. The patients were divided into two groups based on the disease activity in 28 joints based on the erythrocyte sedimentation rate (DAS28-ESR) into the remission or low disease activity group (L group) and the moderate or high disease activity group (H group). Patient demographics and comorbidities in the two groups were compared. Results The most common comorbidity was hypertension (33.7%), followed by renal disease (25.2%), respiratory disease (12.2%), diabetes mellitus (8.1%), cardiovascular disease (8.0%), malignancies (5.7%), and cerebrovascular disease (4.7%). The H group was older (p<0.0001); had a higher prevalence of hypertension (p<0.0001), diabetes (p=0.0011), respiratory disease (p<0.0001), cerebrovascular disease (p<0.0001), and cardiovascular disease (p=0.0030); and was less likely to use anti-rheumatic drugs. The prevalence of comorbidities other than renal disease and malignant tumor was higher in the H group. Multivariate logistic regression analysis showed that female sex (p=0.0054), advanced Steinbrocker class (p<0.0001), high anti-citrullinated protein antibody levels (p=0.0211), high prednisolone dose (p<0.0001), and absence of biologics’ or JAK inhibitors’ use (p<0.0001) were risk factors for high disease activity, and shorter treatment period was a low-risk factor for high disease activity (p=0.0041). Among comorbidities, the presence of cerebrovascular disease (p=0.0334) was the only independent risk factor for high disease activity. Conclusions In our registry study with a high proportion of elderly RA patients, cerebrovascular disease was associated with high disease activity in patients with RA. Therefore, when treating elderly patients with RA, we need to pay careful attention to cerebrovascular disease, and treatment should be aimed at achieving adequate control of RA.