Table 1 Participant characteristics at the time of sampling
Characteristics | Urine and plasma samples | Ligament tissue samples | ||||
|---|---|---|---|---|---|---|
Patients with AS | HC | P valuea | patients with AS | Patients with FNF | P valuea | |
Number of participants | 44 | 44 | – | 30 | 30 | – |
Age, years, mean ± SD | 31.8 ± 10.9 | 33.8 ± 9.7 | 0.350 | 40.6 ± 12.8 | 46.6 ± 11.6 | 0.065 |
 Range | 18–59 | 18–57 | – | 20–71 | 31–72 | – |
 18–29 | 15 | 12 | – | 6 | 2 | – |
 30–49 | 21 | 22 | – | 14 | 13 | – |
 50–79 | 8 | 10 | – | 10 | 15 | – |
Sex, n (%) | Â | Â | 1.000 | Â | Â | 0.037 |
 Female | 6 (13.6 %) | 6 (13.6 %) | – | 4 (13.3 %) | 11 (36.7 %) | – |
 Male | 38 (86.4 %) | 38 (86.4 %) | – | 26 (86.7 %) | 19 (63.3 %) | – |
BMI, kg/m2, mean ± SD | 21.8 ± 2.4 | 22.5 ± 2.9 | 0.226 | 22.8 ± 2.0 | 23.7 ± 1.5 | 0.062 |
 <18.5 | 13 | 12 | – | 9 | 7 | – |
 18.5–25 | 25 | 23 | – | 14 | 15 | – |
 >25 | 6 | 9 | – | 7 | 8 | – |
Disease duration, years, mean ± SD | 6.8 ± 3.5 | – | – | 14.2 ± 4.8 | – | – |
 <5 | 25 | – | – | 0 | – | – |
 5–10 | 18 | – | – | 11 | – | – |
 >10 | 1 | – | – | 19 | – | – |
BASDAI score | 3.2 ± 1.8 | – | – | 5.8 ± 1.1 | – | – |
 0–3 | 20 | – | – | 0 | – | – |
 3–6 | 23 | – | – | 18 | – | – |
 6–10 | 1 | – | – | 12 | – | – |
BASFI score | 3.9 ± 2.1 | – | – | 5.5 ± 0.9 | – | – |
 0–3 | 20 | – | – | 0 | – | – |
 3–6 | 22 | – | – | 19 | – | – |
 6–10 | 2 | – | – | 11 | – | – |
Treatment duration, years, mean ± SD | 2.8 ± 1.5 | – | – | 8.4 ± 3.6 | – | – |
 0 | 32 | – | – | 0 | – | – |
 1–10 | 11 | – | – | 19 | – | – |
 11–20 | 1 | – | – | 9 | – | – |
 >20 | 0 | – | – | 2 | – | – |