Relationship between disease activity of rheumatoid arthritis and development of locomotive syndrome: A five-year longitudinal cohort study.

Objective: This study aimed to longitudinally evaluate the association between rheumatoid arthritis (RA) and locomotive syndrome (LS) in RA patients using the 25-question Geriatric Locomotive Function Scale (GLFS-25).

Methods: Subjects were 58 RA patients (female, 48 (82.8%); mean age, 60.9 ± 10.9 years) who had GLFS-25 scores available for five consecutive years and who did not have LS at baseline (i.e. GLFS-25 < 16 points). Associations between DAS28-CRP and the development of LS were determined using linear regression analysis and receiver operating characteristic (ROC) curve analysis.

Results: Subjects were divided into the LS group ( = 15, GLFS-25 ≥ 16 points) and non-LS group ( = 43, GLFS-25 < 16 points) based on GLFS-25 scores at the 5th year of the study period. In the LS group, DAS28-CRP worsened every year. The linear regression model adjusted for age and sex revealed that ΔGLFS-25 increased by 3.80 (95% confidence interval: 1.81-5.79) each time ΔDAS28-CRP increased by 1 (<.001). Among patients in remission (DAS28-CRP < 2.3), 13.5% had LS. ROC curve analysis yielded a five-year mean DAS28-CRP of 1.99 (sensitivity, 86.7%; specificity, 62.8%) as the cut-off point for the development of LS.

Conclusion: Tight control of RA disease activity for deeper remission may be needed to prevent the development of LS.