Fig. 2

Obesity associates with more swollen joints and higher CRP levels over time in ACPA-positive but not in ACPA-negative RA patients

Trajectories of DAS components for ACPA-positive and ACPA-negative RA patients, per BMI-category over 5-year follow-up. All trajectories are shown for mean age per ACPA population. SJC: obese ACPA-positive RA: 59% higher SJC (IRR1.59 95% CI 1.18, 2.15), obese ACPA-negative RA: no significant difference with normal weight (IRR1.05 95% CI 0.85, 1.32). CRP: obese ACPA-positive RA: + 3.7 mg/L higher CRP (95% CI 0.96, 6.52). Obese ACPA-negative RA: no significant difference (β1.02 95% CI − 1.29, 3.33). TJC: obese ACPA-positive RA: 56% higher TJC (IRR1.56 95% CI 1.16, 2.10). Obese ACPA-negative RA: trend towards 18% higher TJC (IRR 1.18 95% CI 0.93, 1.50). VAS: obese ACPA-positive RA: VAS + 9 units (95% CI 4.5, 14.4). Obese ACPA-negative RA: trend towards + 4 units higher VAS (95% CI − 0.8, 8.5). Patterns were visualized based on estimated marginal means resulting from either the linear or Poisson mixed models. *p-value < 0.05, significant difference compared to normal weight. Abbreviations: ACPA, anti-citrullinated protein antibodies; BMI, body mass index; SJC, swollen joint count; CRP, c-reactive protein; TJC, tender joint count; VAS, visual analog scale