Characteristic | Total RA Population, n = 850 | With Vitamin D Insufficiency, n = 715 | Without Vitamin D Insufficiency, n = 135 | p |
---|---|---|---|---|
Sociodemographic and health measures | ||||
Age, yrs | 64.0 (11.3) | 63.6 (11.2) | 66.3 (11.4) | 0.009 |
Caucasian race/ethnicity | 76 | 74 | 84 | 0.017 |
Men | 90 | 90 | 93 | 0.201 |
High school education or greater | 83 | 82 | 86 | 0.338 |
Ever smoking | 80 | 81 | 77 | 0.328 |
Body Mass Index, kg/m2 | 27.9 (5.7) | 28.1 (5.8) | 26.6 (5.2) | 0.006 |
Comorbidity count (0–8) | 2.0 (1.4) | 2.0 (1.4) | 1.8 (1.3) | 0.187 |
Season of enrollment | ||||
Summer | 24 | 23 | 27 | 0.775 |
Fall | 20 | 20 | 19 | |
Winter | 25 | 25 | 24 | |
Spring | 31 | 31 | 30 | |
RA-related measures | ||||
Anti-CCP antibody-positive, % | 76 | 78 | 67 | 0.009 |
RF-positive, % | 81 | 81 | 78 | 0.388 |
Nodules, % | 39 | 39 | 36 | 0.511 |
Radiographic changes, % | 53 | 53 | 52 | 0.852 |
Pain (0–10) | 4.8 (3.0) | 4.8 (3.0) | 4.6 (3.0) | 0.412 |
MD-HAQ (0–3) | 1.0 (0.6) | 1.0 (0.6) | 1.0 (0.6) | 0.698 |
Tender joint count (0–28) | 5.6 (7.1) | 5.7 (7.2) | 4.8 (6.4) | 0.186 |
Swollen joint count (0–28) | 4.5 (5.6) | 4.5 (5.7) | 4.4 (5.1) | 0.923 |
Disease Activity Score-28 | 4.1 (1.6) | 4.1 (1.6) | 4.1 (1.5) | 0.999 |
Patient global well-being (0–100mm) | 44.6 (26.7) | 44.5 (26.8) | 45.1 (26.3) | 0.814 |
hs-CRP, mg/l | 13.2 (19.5) | 13.1 (19.9) | 13.5 (17.7) | 0.840 |
ESR, mm/h | 27.7 (23.6) | 27.9 (24.0) | 26.9 (21.4) | 0.660 |
Duration of RA at enrollment, yrs | 12.4 (11.5) | 12.4 (11.6) | 12.9 (11.2) | 0.660 |
Medication use, % | ||||
DMARD | 90 | 90 | 92 | 0.453 |
Methotrexate | 54 | 54 | 57 | 0.462 |
Biologic | 32 | 30 | 35 | 0.352 |
Prednisone | 48 | 48 | 47 | 0.903 |
Vitamin D supplementation* | 34 | 32 | 47 | < 0.001 |
↵* Vitamin D use included vitamin D supplements (2.3%), cholecalciferol (0.5%), combination of calcium and vitamin D supplements (24.2%), or patient-reported supplementation from VARA database (16.3%). Anti-CCP: anti-cyclic citrullinated peptide antibody; RF: rheumatoid factor; MD-HAQ: Multidimensional Health Assessment Questionnaire; hs-CRP: high sensitivity C-reactive protein; ESR: erythrocyte sedimentation rate; DMARD: disease modifying antirheumatic drugs.