Table 1 Demographic and disease-specific characteristics of patients with psoriatic arthritis (PsA), patients with psoriasis (PSO) and healthy controls (HC)

 Number of subjects

101

55

47

–

 Sex (male/female)

50/51

35/20

24/23

0.220

 Age (years)

50.8 ± 13.2

49.0 ± 11.4

45.7 ± 12.9

0.056

 Body mass index

28.1 ± 5.7

27.9 ± 5.6

25.0 ± 4.7

0.011

 Smokers, N (%)

28 (27.7)

16 (29.1)

11 (23.4)

0.875

 Duration of PSO (years)

18.9 ± 14.8

15.2 ± 15.4

–

0.071

 Duration of PsA (years)

6.4 ± 7.3

–

–

–

 PASI (units)

3.4 ± 5.5

6.2 ± 8.0

–

0.007

 HAQ

0.8 ± 0.8

0.4 ± 0.5

–

0.003

 DAS28-ESR (units)

2.98 ± 1.48

–

–

–

 Nail involvement, N (%)

21 (20.8)

28 (50.9)

–

0.004

 Scalp involvement, N (%)

20 (19.8)

16 (29.1)

–

0.659

 Positive ACPA, N (%)

1 (1.0)

0

–

0.452

 Positive low-titre RF, N (%)^a

9 (8.9)

4 (7.3)

–

0.681

 C-reactive protein (mg/L)^b

4.9 ± 6.5

3.8 ± 4.6

–

0.228

 Current csDMARDs, N (%)

52 (51.5)

9 (16.4)

–

< 0.001

 Current bDMARDs, N (%)

49 (48.5)

4 (7.3)

–

< 0.001

 Current Glucocorticoids, N (%)

19 (18.8)

0 (0)

–

0.001

 Current NSAIDs, N (%)

31 (30.7)

6 (10.9)

–

0.005

 No systemic treatment, N (%)

13 (12.9)

41 (74.5)

–

< 0.001