Association Between Vitamin D Deficiency and Disease Activity, Disability, and Radiographic Progression in Early Rheumatoid Arthritis: The ESPOIR Cohort

Objective. To evaluate the association of baseline serum level of vitamin D with disease activity, disability, and radiographic damage over the first year in early rheumatoid arthritis (RA). Methods. Among early arthritis patients included in the ESPOIR cohort, patients with early RA were evaluated. Levels of 25-hydroxy vitamin D2 and D3 were measured at baseline. Baseline associations between vitamin D level and 28-joint count Disease Activity Score based on erythrocyte sedimentation rate (DAS28-ESR), Health Assessment Questionnaire-Disability Index (HAQ-DI), and van der Heijde modified total Sharp score (mTSS) were assessed. Bivariate analysis was used to assess the association between vitamin D level and radiographic progression (mTSS increased by >= 1 point) or disability (HAQ-DI >= 0.5) over 12 months. Forward stepwise multiple logistic regression was used to evaluate the independent association of baseline variables and outcomes. Results. Among 813 patients with early arthritis, data for 645 patients with RA were analyzed. Vitamin D level was < 10 ng/mL (deficiency, group 1), 10-29.9 ng/mL (low level, group 2), and >= 30 ng/mL (normal, group 3) for 114 (17.7%), 415 (64.54%), and 114 (17.7%) patients, respectively. At baseline, DAS28-ESR and HAQ-DI were higher with vitamin D deficiency compared with groups 2 and 3 combined (P = 0.007 and P = 0.001, respectively), as was mean mTSS, but not significantly (p = 0.076). On multivariate analysis, baseline vitamin D deficiency was associated with HAQ-DI at 6 months (OR 1.70) and mTSS at 12 months (OR 1.76). Conclusion. Vitamin D deficiency was associated with more active and severe disease at baseline and may predict disability and radiographic progression over 1 year in early RA patients. [ClinicalTrials.gov: NCT03666091]