Table 3 Median serum trough level of adalimumab and etanercept in groups divided by inactive and active disease or normal BMI and overweight/obesity

ASDAS inactive disease (< 2.1)

ASDAS active disease (≥ 2.1)

P-value

Adalimumab

6.7 (4.0–10.5)

5.0 (3.3–7.8)

0.43

Etanercept

1.4 (1.1–2.4)

1.9 (0.5–2.3)

0.96

BASDAI inactive disease (< 4.0)

BASDAI active disease (≥ 4.0)

Adalimumab

7.0 (4.0–8.9)

4.9 (3.3–7.1)

0.23

Etanercept

1.6 (1.2–2.4)

0.9 (0.1–2.1)

0.24

CRP < 5 mg/L

CRP ≥ 5 mg/L

Adalimumab

5.3 (4.3–8.0)

5.0 (1.5–8.0)

0.56

Etanercept

1.6 (1.2–2.5)

1.4 (0.4–2.3)

0.37

Normal BMI (< 25 kg/m²)

Overweight/obesity (≥ 25 kg/m²)

Adalimumab

8.9 (5.4–11.0)

4.9 (3.3–7.0)

0.012

Etanercept

2.0 (1.3–2.5)

1.2 (0.5–1.8)

0.042