Table 4 Baseline characteristics associated with incident CAC (among RA patients free of CAC at baseline)
| Â | Incident CAC: yes | Incident CAC: no | P-value | IRR (95% CI) | Adjusted IRRa(95% CI) |
|---|---|---|---|---|---|
Demographics | Â | Â | Â | Â | Â |
  Age, years | 59 ± 7 | 55 ± 6 | 0.03 | 1.06 (1.0, 1.14) | NA |
  Male; number (%) | 5 (25%) | 8 (15%) | 0.32 | 1.65 (0.71, 3.84) | 1.81 (0.79, 4.18) |
  Caucasian race; number (%) | 19 (95%) | 44 (83%) | 0.18 | 3.03 (0.45, 20.7) | 2.58 (0.39, 17.3) |
  Education; number (%) | 16 (80%) | 44 (83%) | 0.76 | 0.86 (0.33, 2.21) | 0.85 (0.32, 2.27) |
    Some college or higher |  |  |  |  |  |
Cardiovascular Risk Factors | Â | Â | Â | Â | Â |
  Diabetes; number (%) | 1 (5%) | 2 (4%) | 0.81 | 1.14 (0.20, 6.46) | 1.08 (0.21, 5.65) |
  Hypertension (%) | 11 (55%) | 21 (40%) | 0.24 | 1.56 (0.73, 3.33) | 1.42 (0.67, 3.0) |
    Systolic BP, mm Hg | 129 ± 17 | 117 ± 15 | 0.01 | 1.03 (1.01, 1.05) | 1.02 (1.0, 1.04)* |
    Diastolic BP, mm Hg | 76 ± 9 | 72 ± 8 | 0.09 | 1.03 (0.99, 1.09) | 1.05 (1.01, 1.09)* |
  Dyslipidemia (%) |  |  |  |  |  |
    Total cholesterol, mg/dL | 201 ± 29 | 192 ± 41 | 0.40 | 1.0 (0.99, 1.01) | 1.0 (0.99, 1.01) |
    LDL cholesterol, mg/dL | 116 ± 20 | 112 ± 34 | 0.66 | 1.0 (0.99, 1.01) | 1.0 (0.99, 1.01) |
    HDL cholesterol, mg/dL | 57 ± 16 | 61 ± 19 | 0.51 | 0.99 (0.97, 1.01) | 0.98 (0.96, 1.01) |
    Triglycerides, mg/dL | 137 ± 86 | 97 ± 60 | 0.03 | 1.0004 (1.0, 1.01) | 1.004 (1.0, 1.01)* |
  Cigarette Smoking |  |  |  |  |  |
    Current; number (%) | 2 (10%) | 4 (8%) | 0.73 | 1.26 (0.36, 4.49) | 0.97 (0.24, 3.94) |
Serum inflammatory markers | Â | Â | Â | Â | Â |
  CRP, mg/L; median (IQR) | 2.1 (0.5 to 9.6) | 2.1 (0.8 to 5.2) | 0.74 | 0.96 (0.72, 1.27) | 0.99 (0.75, 1.32) |
  IL-6, pg/mL; median (IQR) | 4.0 (1.2 to 7.7) | 2.3 (1.1 to 7.5) | 0.45 | 1.12 (0.79, 1.58) | 1.17 (0.83, 1.64) |
  Fibrinogen, mg/dL; median (IQR) | 362 (260 to 473) | 338 (278 to 383) | 0.89 | 1.08 (0.33, 3.50) | 1.23 (0.39, 3.94) |
  E-selectin, ng/mL; median (IQR) | 49 (25 to 76) | 45 (29 to 59) | 0.90 | 1.0 (0.53, 1.88) | 1.02 (0.58, 1.80) |
  s-ICAM-1, ng/mL; median (IQR) | 312 (247 to 383) | 275 (225 to 322) | 0.12 | 1.60 (0.58, 4.40) | 1.31 (0.47, 3.62) |
Disease characteristics at baseline | Â | Â | Â | Â | Â |
  Disease duration (years) | 7 (4 to 14) | 10 (5 to 20) | 0.13 | 0.98 (0.94, 1.02) | 0.97 (0.94, 1.01) |
  DAS28 | 3.9 ± 0.9 | 3.7 ± 1.0 | 0.44 | 1.19 (0.81, 1.75) | 1.20 (0.81, 1.78) |
  HAQ | 0.5 ± 0.7 | 0.5 ± 0.6 | 0.87 | 1.10 (0.60, 2.04) | 1.12 (0.64, 1.95) |
  Sharp score; median (IQR) | 29 (15 to 73) | 44 (11 to 90) | 0.93 | 1.0 (0.99, 1.0) | 1.0 (0.99, 1.0) |
  Current use of MTX | 10 (50%) | 38 (72%) | 0.08 | 0.52 (0.24, 1.09) | 0.51 (0.25, 1.04) |
  Current use of biologic agents | 11 (55%) | 24 (45%) | 0.46 | 1.30 (0.61, 2.79) | 1.29 (0.62, 2.68) |
  Current use of corticosteroids | 7 (35%) | 19 (36%) | 0.95 | 0.95 (0.43, 2.11) | 1.02 (0.46, 2.26) |
Disease characteristics, expressed as average over follow-up | Â | Â | Â | Â | Â |
  DAS28 | 3.5 ± 1.0 | 3.5 ± 1.0 | 0.90 | 1.04 (0.7, 1.6) | 1.06 (0.7, 1.6) |
  CRP, mg/L; median (IQR) | 2.0 (0.9 to 6.5) | 2.2 (1.2 to 6.2) | 0.72 | 1.0 (1.0, 1.1) | 1.0 (1.0, 1.1) |
  IL-6, pg/mL; median (IQR) | 4.7 (1.5 to 20.9) | 3.7 (2.0 to 11.5) | 0.87 | 1.0 (1.0, 1.2) | 1.0 (1.0, 1.1) |
  Fibrinogen, mg/dL; median (IQR) | 358 (283 to 425) | 361 (310 to 419) | 0.78 | 1.0 (1.0, 1.0) | 1.0 (1.0, 1.0) |
  E-selectin, ng/mL; median (IQR) | 44 (34 to 61) | 43 (34 to 65) | 0.78 | 1.0 (1.0, 1.0) | 1.0 (1.0, 1.0) |
  s-ICAM-1, ng/mL; median (IQR) | 327 (242 to 367) | 266 (240 to 323) | 0.12 | 1.0 (1.0, 1.0) | 1.0 (1.0, 1.0) |