Table 1 Baseline clinical characteristics and differences in spirometry and IOS parameters between patients with rheumatoid arthritis with normal and those with abnormal findings in HRCT
|  | Abnormal on HRCT (n = 35) | Normal on HRCT (n = 13) | p-value |
|---|---|---|---|
Age, years | 69.0 (65.0–70.0) | 55.0 (44.2–60.9) |  < 0.001 |
Sex, female (%) | 28 (80.0) | 10 (76.9) | 0.818 |
RF | 234.4 (101.5–367.2) | 129.5 (38.7–220.4) | 0.183 |
RF( +) (%) | 19 (54.3) | 8 (61.5) | 0.656 |
Anti-CCP | 381.2 (198.6–563.7) | 114.5 (6.67–222.3) | 0.013 |
Anti-CCP( +) (%) | 24 (68.6) | 9 (69.2) | 0.965 |
CRP | 0.56 (0.23–0.89) | 0.18 (0.10–0.25) | 0.029 |
ESR | 18.8 (13.1–24.5) | 17.5 (7.68–27.4) | 0.814 |
Spirometry | |||
 FVC (%) | 91.9 (87.3–95.7) | 102.4 (95.6–110.8) | 0.038 |
 FEV1/FVC (%) | 79 (75.2–81.0) | 82 (79.1–86.0) | 0.024 |
 MMEF25/75 (%) | 57.6 (48.9–66.1) | 77.9 (71.9–102.5) | 0.001 |
 RV (%) | 102 (91.6–109.4) | 106.0 (89.6–118.6) | 0.492 |
IOS | |||
 R5 (%) | 150 (128.7–176.3) | 110 (93.6–128.0) | 0.004 |
 R20 (%) | 132 (118.3–146.7) | 116 (106.0–133.8) | 0.107 |
 X5 < -0.12 | -0.18 (-0.22–-0.15) | -0.13 (-0.15–-0.11) | 0.011 |
 R5-R20 > 0.07 | 0.13 (0.06–0.18) | 0.05 (0.01–0.08) | 0.008 |
 Fres > 14.14 | 16.0 (14.9–21.8) | 12.1 (10.1–14.2) | 0.006 |
 AX > 0.44 | 1.00 (0.56–1.89) | 0.40 (0.23–0.60) | 0.001 |
DLCO (%) | 66.7 (56.3–76.7) | 71.3 (61.1–89.8) | 0.167 |