Table 1

Demographic characteristics

MTX-naïve
Pre-exposure (n=20)
MTX-naïve
Post-exposure (n=18)
Healthy controls (n=25)MTX chronic§ (n=5)P value
General information
Age years, mean (95% CI)35.2 (31.4 to 39.1)34.7 (32.9 to 36.7)36.6 (32.1 to 41.1)NS
Smoking, n (%)4 (20)4 (20)6 (24)1 (20)NS
BMI %, mean (95% CI)27.1 (24.8 to 29.2)26.8 (24.5 to 29.1)25.5 (24.2 to 26.8)25.5 (21.4 to 29.6)NS
Testicular volume, mean (95% CI)22.9 (21.4 to 24.3)22.6 (21.3 to 23.8)22.6 (21.3 to 23.8)NS
Inflammatory arthritis
Diagnosis:
RA, n (%)7 (35.0)6 (33.3)-2 (40.0)
PsA, n (%)8 (40.0)7 (38.9)-1 (20.0)
SpA, n (%)1 (5.0)1 (5.6)-2 (40.0)
Psoriasis, n (%)4 (20.0)4 (22.2)-0 (0.0)
Age at diagnosis, mean (SD)27.4 (22.1–32.6)28.5 (24.5–34.5)30.3 (18.5–42.1)
Disease duration, mean (SD)6.9 (2.1–11.8) - 5.6 (-5.5–16.8)
MTX dose (mg/week), mean (95% CI)16.0 (13.6 to 18.4)18.3 (15.6 to 21.1)
Prednisone exposure, n (%)2 (10.0)6 (33.3)--1 (20)NS
TNFa inhibitor exposure, n (%)3 (15.0)5 (27.8)--2 (40)NS
C reactive protein mg/dL, median (IQR)2.1 (0.6–5.0)1.4 (1.0–3.2)0 (0.0–0.9)1.1 (0–1.8)* p=0.011
† p=0.008
Disease activity scores
VAS general health mm,
mean (95% CI)
42 (19 to 67)20 (12 to 36)17.7 (10.5 to 25-5)20.20 (0.3 to 40.1)* p=<0.001
‡ p=0.008
VAS pain mm, mean (IQR)42 (5.5–75)14 (4–36)--11 (4–34)
VAS activity mm, mean (IQR)68 (51–78)27 (16–49)--10 (4–52)
RA: DAS28, mean (IQR)2.7 (2.4–2.9)2.55 (1.34–3.40)--2.3 (1.4–2.7)
PsA: DAPSA, mean (IQR)24.1 (20.5–33.3)17.8 (11.2–22.7)--1.1 (1.1–1.1)
Psoriasis: PASI, mean (IQR)1.9 (1.3–5.1)1.1 (0.7–3.1)--0.8 (0.3–1.2)
  • *Statistically significant difference between pre-exposure and healthy controls.

  • †Statistically significant difference between post-exposure and healthy controls.

  • ‡Statistically significant difference between pre-exposure and post-exposure.

  • §Presented only for descriptive purposes, no statistical analyses were conducted.

  • BMI, body mass index; DAPSA, disease activity index for psoriatic arthritis; DAS28, disease activity score 28; MTX, methotrexate; PsA, psoriatic arthritis; RA, rheumatoid arthritis; SpA, spondyloarthritis; TNFa, tumour necrosis factor alpha; VAS, visual analogue scale.