Table 1.

Demographic and disease characteristics by presence of diffuse idiopathic skeletal hyperostosis (DISH).

DISH, Mean (SD) or Frequency (%)
CharacteristicYes, n = 78No, n = 234p*
Age, yrs62.9 (8.9)49.3 (12.8)< 0.0001
Age at diagnosis of psoriasis, yrs39.1 (15.4)28.3 (14.1)< 0.0001
Age at diagnosis of PsA, yrs48.0 (13.0)36.5 (12.1)< 0.0001
Duration of psoriasis, yrs23.9 (14.7)21.0 (13.1)0.01
Duration of PsA, yrs15.1 (11.7)12.8 (10.3)0.03
Sex, males/females (%)57 (73.1)/21 (26.9)171 (73.4)/62 (26.6)NS
Body mass index32.9 (5.6)28.7 (5.8)< 0.0001
Obesity (%)31 (70.5)50 (33.8)< 0.0001
Enthesitis (%)8 (10.3)26 (11.2)0.88
Damaged joint count11.9 (16.4)6.7 (11.6)< 0.0001
Active joint count10.5 (10.9)8.1 (9.3)0.27
Diabetes (%)21 (28.0)22 (9.8)< 0.0001
Hypertension (%)39 (50.0)58 (24.9)< 0.0001
Angina (%)3 (3.9)3 (1.3)0.15
Myocardial infarction (%)2 (3.1)2 (1.1)0.25
Inflammatory back pain (%)10 (18.5)36 (21.7)0.88
C-reactive protein10.8 (12.5)10.0 (13.5)0.79
Erythrocyte sedimentation rate20.6 (16.9)14.4 (15.4)< 0.0001
Elevated uric acid levels (%)12 (16.0)15 (7.0)0.01
NSAID (%)45 (72.6)131 (66.5)0.26
DMARD (%)39 (61.9)124 (63.9)0.63
Biologics14 (28.0)55 (31.8)0.69
UVT (%)8 (11.0)30 (13.9)0.53
Radiographic damage (%)66 (84.6)158 (67.8)< 0.0001
Modified Steinbrocker score (%)32.0 (39.8)19.5 (31.4)0.0001
Calcaneal spurs (%)65 (83.3)142 (60.9)< 0.0001
Syndesmophytes (%)30 (38.5)43 (18.7)< 0.0001
  Classical24 (30.8)32 (13.9)< 0.0001
  Paramarginal18 (23.1)21 (9.1)< 0.0001
Sacroiliitis (%)37 (47.4)110 (47.2)0.70
Grade IV sacroiliitis (%)11 (14.5)18 (7.8)0.01
HLA-B278 (11.8)30 (14.8)0.42
HLA-C6 (%)13 (19.1)58 (28.6)0.02
HAQ score0.86 (0.74)0.56 (0.62)0.0007
BASMI score5.8 (2.1)5.1 (2.6)< 0.0001
Left cervical spine rotation, degrees63.1 (19.6)73.8 (15.9)< 0.0001
Right cervical spine rotation, degrees62.9 (18.3)73.9 (17.1)< 0.0001
Occiput to wall distance, cm3.7 (5.2)1.1 (4.9)< 0.0001
Tragus to wall distance, cm13.2 (4.1)12.0 (8.2)0.09
Modified Schober’s test, cm4.4 (1.3)4.7 (1.2)0.02
Internal rotation of hip, cm29.8 (12.4)36.4 (11.5)< 0.0001
Intermalleolar distance, cm95.1 (23.3)105.9 (24.4)< 0.0001
Left lateral flexion**, cm13.8 (6.4)17.1 (4.5)< 0.0001
Right lateral flexion**, cm13.0 (4.5)17.5 (4.6)< 0.0001
INSPIRE method, cm26.2 (11.2)32.2 (9.6)< 0.0001
Chest expansion at xyphisternum, cm4.9 (1.7)6.6 (6.6)0.0002
  • * McNemar test for categorical variables and paired t test for continuous variables (takes matching into consideration).

  • ** DOMJAN method. PsA: psoriatic arthritis; NSAID: nonsteroidal antiinflammatory drug; DMARD: disease-modifying antirheumatic drug; HAQ: Health Assessment Questionnaire; BASMI: Bath Ankylosing Spondylitis Metrology Index; UVT: ultraviolet therapy.