Table 1.
Characteristics of the study population.
| Characteristics | Healthy controls (n=88) | Early-RA (n=66) | Established-RA (n=98) | axSpA (n=69) |
|---|---|---|---|---|
| Age (years) | 53 ± 11 ($) | 57 ± 13 ($) | 57 ± 13 ($$) | 48 ± 13 |
| Female | 67 (76) ($$$) | 46 (70) ($$$) | 79 (81) ($$$) | 28 (41) |
| Smokers | – | 32 (48) | 45 (46) | 32 (52) |
| Disease duration (years) | – | – | 9 (4-15) | 7 (3-16) |
| RF | – | 36 (54) (##) | 75 (77) | – |
| ACPA | – | 40 (60) (##) | 78 (80) | – |
| HLA-B27 | – | – | – | 49 (72) |
| BMI (kg/m2) | – | 27.0 ± 4.4 | 26.6 ± 4.9 | 27.1 ± 5.0 |
| BMI≥25 kg/m2 | – | 42 (68) | 58 (59) | 41 (59) |
| DAS28 | – | 4.4 ± 1.4 (##) | 4.9 ± 1.3 | – |
| ASDAS | – | – | – | 3.5 ± 1.0 |
| CRP (mg/L) | – | 1 (0-3) (###,$$$) | 6 (2-20) | 8 (3-24) |
| csDMARDs | – | 4 (6) (###,$$$) | 91 (93) ($$$) | 40 (58) |
| Prednisone | – | 20 (31) (##,$) | 57 (58) ($$$) | 9 (13) |
The table shows the mean ± SD, median (IQR) or absolute number (percentage) of the four groups included in the study (n=321). A P value<0.05 was considered statistically significant. Difference with early-RA. #Difference with established-RA. $Difference with axSpA ($: P<0.05; ##, $$: P<0.01; ###, $$$: P<0.0001). ACPA, anti–citrullinated peptide antibody; ASDAS, Ankylosing Spondylitis Disease Activity Index; BMI, body mass index; CRP, C-reactive protein; csDMARD, conventional synthetic disease-modifying antirheumatic drug; DAS28, 28-joint disease activity score; HLA-B27, human leukocyte antigen B27; RA, rheumatoid arthritis; RF, rheumatoid factor.