Table 1 Baseline characteristics of the patients with or without the presence of RA-ILD ^(n=732)

Age at diagnosis of RA (mean ± SD)

56.5 ± 13.7

46.4 ± 15.4

< 0.001 **

Age at diagnosis of RA-ILD (mean ± SD)

61.9 ± 12.2

--

--

Female gender

42 (77.8%)

608 (89.7%)

0.008 **

Male gender

12 (22.2%)

70 (10.3%)

Smoking

 • Ever smoked

09 (16.7%)

20 (2.9%)

< 0.001 **

 • Never smoked

45 (83.3%)

658 (97.1%)

Comorbidities

 • DM

23 (42.6%)

130 (19.2%)

< 0.001 **

 • HTN

26 (48.1%)

171 (25.3%)

< 0.001 **

 • DLP

04 (07.4%)

57 (08.4%)

0.793

 • Hypothyroidism

11 (20.4%)

91 (13.5%)

0.159

 • IHD

08 (14.8%)

12 (01.8%)

< 0.001 **

 • OA

10 (18.5%)

63 (09.3%)

0.030 **

 • Osteoporosis

07 (13.0%)

52 (07.7%)

0.171

 • Others

17 (56.7%)

175 (68.6%)

0.186

Seropositive

 • RF

35 (71.4%)

356 (59.9%)

0.113

 • Anti-CCP

31 (66.0%)

334 (58.2%)

0.298

 • Double positive

03 (09.1%)

50 (16.3%)

0.279

 • Seronegative

01 (03.0%)

21 (06.8%)

0.400

 • Antinuclear Antibody (ANA)

24 (60.0%)

332 (67.9%)

0.306