Skip to main content

Table 2 Association of BMI with MRI-detected inflammation in patients with RA, early arthritis patients with other arthritides, and asymptomatic volunteers

From: Body mass index and extent of MRI-detected inflammation: opposite effects in rheumatoid arthritis versus other arthritides and asymptomatic persons

  Rheumatoid arthritis (n = 195) Other arthritides (n = 159) Asymptomatic volunteers (n = 193)
  β (95 % CI) p value β (95 % CI) p value β (95 % CI) p value
Univariable
 BMI 0.97 (0.94–1.00) 0.024 1.082 (1.041–1.13) <0.001 1.029 (1.001–1.057) 0.040
Multivariable
 Model 1
  BMI 0.96 (0.94–0.99) 0.005 1.036 (1.00–1.075) 0.054 1.022 (1.001–1.044) 0.040
  Age 1.025 (1.017–1.033) < 0.001 1.033 (1.024–1.041) < 0.001 1.031 (1.025–1.036) < 0.001
  Gender 1.13 (0.89–1.44) 0.30 0.88 (0.67–1.15) 0.34 1.010 (0.84–1.21) 0.92
 Model 2
  BMI 0.96 (0.94–0.99) 0.003 1.039 (1.001–1.078) 0.043 NA  
  Age 1.022 (1.014–1.030) < 0.001 1.030 (1.021–1.039) < 0.001 NA  
  Gender 1.12 (0.89–1.41) 0.35 0.93 (0.71–1.23) 0.62 NA  
  CRP 1.007 (1.003–1.012) 0.001 1.002 (0.998–1.006) 0.29 NA  
  ACPA positivity 0.96 (0.77–1.20) 0.72 1.55 (0.75–3.20) 0.24 NA  
  1. Total inflammation scores were log-transformed for regressions. Regression coefficients presented are back-transformed (10β and 1095 % CI). Therefore, the effect size (β) can be interpreted as the fold increase in MRI-detected inflammation per point increase in BMI. Thus, an effect size of < 1 means a decrease in MRI-detected inflammation per unit increase in BMI and an effect size of > 1 means an increase in MRI-detected inflammation per unit increase in BMI. The raw beta coefficients are presented in Additional file 3
  2. BMI body mass index, MRI magnetic resonance imaging, RA rheumatoid arthritis, NA not assessed, CRP C-reactive protein, ACPA anti-citrullinated protein antibody