Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.

Recently Diagnosed Ankylosing Spondylitis: Gender Differences and Factors Related to Delay in the Diagnosis. The North Israeli Study of ANkylosing Spondylitis (NISAN).

Slobodin1,  Gleb, Reychan7,  Iris, Avshovich5,  Nina, Balbir-Gurman6,  Alexandra, Boulman2,  Nina, Elias3,  Mona, Feld3,  Joy

Bnai Zion Medical Center, Haifa, Israel
Bnai Zion Medical Center
Carmel Medical Center
Haemek Medical Center, Afula, Israel
Hillel Yaffe Mecial Center
Rambam Medical Center


Gender differences have been demonstrated in patients with advanced ankylosing spondylitis (AS). There are no studies evaluating this in patients with recently diagnosed disease. The aim of the study was to characterize a cohort of patients with recently diagnosed AS, both preradiographic and established, with emphasis on gender differences and factors leading to delay in diagnosis.


All consecutive patients diagnosed with AS in 2004–2009 were recruited over a 6 month period by participating rheumatologists. Clinical, laboratory and imaging data was collected during the screening visit and/or retrospectively for all patients enrolled.


Seventy-nine men and 72 women with AS were enrolled.

Both groups (men versus women) had similar age of onset of disease-related symptoms, as well as similar delay time to diagnosis, follow-up duration and frequency of anti-TNF treatment. Typical inflammatory back pain as a first symptom related to AS was reported more often by men (p=0.02). Women reported significantly more frequent lower abdominal or pelvic pain (p=0.0032), heel pain (p=0.003) and widespread pain (WP) (p=0.0001) during the course of AS. There was no gender-related difference in the incidence of uveitis, dactylitis or peripheral joint involvement. At the time of diagnosis, men were more limited in chest expansion (p=0.012) and showed increased occiput-to-wall distance compared to women (p=0.0032). At diagnosis, elevated erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) were detected in a similar proportion of men and women. X-ray films were more often diagnostic for AS in males, with more females undergoing CT or MRI studies to confirm the presence of sacroiliitis (p=0.018). In the subgroup analysis, women with WP had longer delay to diagnosis (p=0.0073) and more frequently elevated ESR/CRP levels (p=0.0068) compared to women without WP. No other statistically significant differences in disease presentation or burden, laboratory findings, or imaging characteristics were demonstrated to correlate with delay to diagnosis.


Women constituted almost 50% of all recently diagnosed patients with AS, with CT or MRI studies more frequently utilized in their diagnosis. Gender-related differences were demonstrated in both disease presentations and burden. WP in women was frequently reported, being related to significant delay in the diagnosis. As no other disease-related features were found responsible for delay in AS diagnosis, the physician's high level of suspicion may be the dominant factor in the early diagnosis of AS.

Table 1. Gender-dependent features of AS

VariableMen (79)Women (72)p
Age at diagnosis (years)35.6 ± 11.738.5 ± 12.30.13
Delay time to diagnosis (years)5.9 ± 6.45.7 ± 6.00.87
Follow-up time (years)2.1 ± 1.51.9 ± 1.20.3
Frequency of anti-TNFa usage (%)37/79 (47%)33/72 (46%)1
Presenting symptom (%)   
  Inflammatory low back pain70 (89%)52 (73%)0.02
  Neck pain4 (5%)8 (11%)0.23
    knee11 (14%)8 (11%)0.6
    hip4 (5%)1 (1.4%)0.36
  Heel pain1 (1.3%)5 (7%)0.23
  Uveitis4 (5%)5 (7%)0.74
Symptoms at the time of diagnosis   
  Inflammatory low back pain74 (94%)70 (97%)0.45
    Non radiating2070.016
    Lower abdomen or pelvis3140.0032
  Musculoskeletal chest/rib pain5 (6.3%)12 (17%)0.07
  Neck pain21 (26%)27 (37%)0.16
  Arthritis or arthralgia40 (51%)42 (58%)0.4
  Heel pain18 (23%)33 (46%)0.003
  Dactylitis2 (2.5%)3 (4.2%)0.67
  Uveitis9 (12%)8 (11%)0.8
  Widespread pain5 (6.3%)28 (39%)<0.0001
  Diarrhea/Crohn's disease4/29/10.14
  Physical examination [N]*:   
    Schober test (cm)3.4 ± 1.5 [64]3.4 ± 1.5 [50]0.87
    Finger-to-floor distance (cm)19.5 ± 15.6 [59]17.2 ± 13.3 [42]0.42
    Occiput-to-wall distance (cm)3.0 ± 5.9 [62]0.2 ± 0.8 [40]0.0032
    Chest expansion (cm)3.4 ± 1.8 [59]4.4 ± 2.1 [38]0.012
  Elevated ESR31 (48%) [65]42 (62%) [62]0.19
  Elevated CRP51 (69%) [74]43 (65%) [65]0.72
CT/MRI studies of SIJ43 (54%)53 (74%)0.018
*[N] - number of subjects with available measurements

Table 2. Disease features in AS women with and without widespread pain (WP) #

VariableWith WP (28)Without WP (41)p
Age at diagnosis (years)43.3 ± 11.735.4 ± 12.10.0091
Delay time to diagnosis (years)8.3 ± 7.24.3 ± 4.80.0073
Follow-up time (years)1.8 ± 1.12.0 ± 1.30.35
Frequency of anti-TNFa usage (%)15/28 (54%)17/41 (41%)0.34
Symptoms of the disease:   
  Inflammatory low back pain28 (100%)39 (95%)0.51
  Musculoskeletal chest/rib pain9 (32%)2 (5%)0.005
  Neck pain18 (64%)8 (20%)0.0003
  Joint involvement15 (54%)26 (63%)0.46
  Heel pain16 (57%)16 (39%)0.15
  Dactylitis0 (0%)3 (7%)0.27
  Uveitis3 (11%)4 (10%)1
  Diarrhea3 (11%)5 (12%)1
Lower abdominal or pelvic pain6 (21%)5 (12%)0.33
  Physical examination [N]*:   
    Schober test (cm)3.2 ± 1.3 [20]3.6 ± 1.6 [29]0.4
    Finger-to-floor distance (cm)19.6 ± 14.9 [21]15.1 ± 11.9 [24]0.26
    Chest expansion (cm)4.1 ± 2.3 [17]4.6 ± 1.9 [21]0.42
  Elevated ESR or CRP25 (63%)24 (59%)0.0068
CT/MRI studies of SIJ18 (64%)33 (80%)0.16
#only 69 of 72 women were included to this subgroup analysis due to absence of data regarding WP in 3 women
*[N] - number of subjects with available measurements

To cite this abstract, please use the following information:
Slobodin, Gleb, Reychan, Iris, Avshovich, Nina, Balbir-Gurman, Alexandra, Boulman, Nina, Elias, Mona, et al; Recently Diagnosed Ankylosing Spondylitis: Gender Differences and Factors Related to Delay in the Diagnosis. The North Israeli Study of ANkylosing Spondylitis (NISAN). [abstract]. Arthritis Rheum 2010;62 Suppl 10 :550
DOI: 10.1002/art.28319

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