Table 1 Demographic and clinical characteristics of study participants (n = 549) and CTD-matched participants (n = 258) stratified by ILD
Total study population (n = 549) | Matched subgroup* (n = 258) | |||||
|---|---|---|---|---|---|---|
ILD(+) (n = 165) | ILD(−) (n = 384) | p value | ILD(+) (n = 129) | ILD(−) (n = 129) | p value | |
Mean age, years (SD) | 56.4 (13.0) | 51.1 (14.3) | < 0.001 | 55.1 (14.0) | 54.5 (14.8) | 0.721 |
Sex, male (%) | 27 (16.4) | 44 (11.5) | 0.116 | 25 (19.4) | 22 (17.1) | 0.628 |
Type of CTD (%) | ||||||
RA | 41 (24.8) | 106 (27.6) | – | 41 (31.8) | 41 (31.8) | – |
SSc | 53 (32.1) | 21 (5.5) | – | 21 (16.3) | 21 (16.3) | – |
IM | 56 (33.9) | 52 (13.5) | – | 52 (40.3) | 52 (40.3) | – |
Others (SLE or SS) | 15 (9.2) | 205 (53.4) | – | 15 (11.6) | 15 (11.6) | – |
Inflammatory markers† (SD) | ||||||
Mean ESR, mm/h | 39.0 (24.9) | 32.4 (25.7) | 0.006 | 39.5 (24.5) | 30.2 (26.3) | 0.004 |
Mean CRP, mg/dL | 0.97 (1.98) | 1.01 (1.97) | 0.828 | 1.12 (2.13) | 1.03 (1.97) | 0.744 |
Serum KL-6, U/mL (SD) | 741.0 (724.3) | 236.1 (157.0) | < 0.001 | 693.8 (679.0) | 256.0 (224.4) | < 0.001 |
Pulmonary function (SD) | ||||||
Mean FVC% | 77.2 (17.3) | – | – | 77.5 (17.3) | – | – |
Mean DLCO% | 61.3 (16.9) | – | – | 63.2 (16.4) | – | – |
Semiquantitative CT grade (%) | (n = 145) | (n = 112) | ||||
Grade 1 (0–25) | 61 (42.1) | – | – | 51 (45.5) | – | – |
Grade 2 (26–50) | 39 (26.9) | – | – | 31 (27.7) | – | – |
Grade 3 (51–75) | 31 (21.4) | – | – | 20 (17.9) | – | – |
Grade 4 (76–100) | 14 (9.6) | – | – | 10 (8.9) | – | – |