The impact of aging and glucocorticoid use on physical function of older rheumatoid arthritis in remission: analysis of a National Database of Rheumatic Disease in Japan.

Abstract

Objective: To investigate clinical features and physical function in rheumatoid arthritis (RA) in remission with and without glucocorticoid (GC).

Methods: Data from 2078 RA patients aged 55-84 years in remission (simplified disease activity index (SDAI) ≤ 3.3) and at stage I/II according to the Steinbrocker classification were extracted from the National Database of Rheumatic Diseases in Japan (NinJa) which includes 11,036 patients from 2017 to 2018 before the coronavirus pandemic. Patients were stratified into six groups: RA aged 55-64, aged 65-74, and aged 75-84 with or without GCs. The primary outcome was the health assessment questionnaire disability index (HAQ-DI) > 0.5, and interactions of age and GC use on the HAQ-DI > 0.5 were examined by multivariable logistic regression.

Results: GC use in patients in remission increased with age. Methotrexate and biological disease-modifying antirheumatic drug prescriptions were similar in patients aged 75-84 with and without GC. Significantly more GC users aged 75-84, but not aged 65-74 and 55-64, had a HAQ-DI > 0.5 than GC non-users (23.9% vs. 14.8%, P = 0.015). An interaction between age and GC use for HAQ-DI > 0.5 was observed, and the adjusted odds ratios (ORs) relative to GC non-users aged 55-64 for HAQ-DI > 0.5 increased to 4.72 (95% CI 2.49-8.96, P < 0.001) for GC non-users aged 75-84 and 7.62 (95% CI 3.70-15.7, P < 0.001) for GC users aged 75-84.

Conclusions: Decline in physical function among GC users was observed in patients aged 75-84, and increasing age and GCs were mutually associated with physical dysfunction of patients in remission. Key Points • The proportion of patients who were in remission but still using glucocorticoids increased with age. • Proportions of patients in remission with HAQ-DI > 0.5 were significantly higher in the patients aged 75-84 with GCs than those without GCs but not in the patients aged 55-64 and 65-74. • Glucocorticoid use for patients in remission was more strongly associated with impaired physical function in patients aged 75-84 than in patients aged 55-74 years.