Table 3.
Adjusted associations of psychosocial variables with CAC: RA versus non-RA and the effect of markers of inflammation*
| Outcome CAC >100 | RA
|
Controls
|
Interaction testing
|
Adding inflammation markers
|
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Adj OR (95% CI) | P | Adj OR (95% CI) | P | Multi-plicative/Additive P† | New adj OR (95% CI)‡ | P | IL-6, P | New adj OR (95% CI)§ | P | CRP, P | |
| Anxiety | 1.10 (1.01–1.20) | 0.029 | 0.93 (0.90–0.97) | 0.001 | 0.001/< 0.001 | 1.10 (1.01–1.20) | 0.028 | 0.657 | 1.11 (1.01–1.21) | 0.025 | 0.468 |
| Anger | 1.14 (1.01–1.29) | 0.037 | 1.00 (0.95–1.04) | 0.87 | 0.051/0.013 | 1.14 (1.01–1.30) | 0.037 | 0.722 | 1.14 (1.01–1.29) | 0.038 | 0.627 |
| CES-D | 1.05 (0.99–1.10) | 0.059 | 0.98 (0.96–1.01) | 0.222 | 0.012/0.001 | 1.05 (0.99–1.11) | 0.055 | 0.611 | 1.05 (1.00–1.11) | 0.043 | 0.336 |
| CES-D ≥16 vs. <16 units | 3.41 (1.11–10.5) | 0.032 | 0.83 (0.45–1.52) | 0.547 | 0.027/0.135 | 3.54 (1.14–11.0) | 0.028 | 0.456 | 3.69 (1.18–11.6) | 0.025 | 0.329 |
| Caregiver stress vs. none | 2.86 (1.23–6.66) | 0.014 | 1.03 (0.73–1.45) | 0.857 | 0.077/0.107 | 2.79 (1.19–6.50) | 0.018 | 0.623 | 2.84 (1.22–6.62) | 0.015 | 0.551 |
Odds ratios represent the average unit change in the frequency of CAC >100 units per 1-unit higher psychosocial variable score. RA models adjusted for age, sex, smoking, RA duration, and past/current prednisone use. Models of categorical depression and caregiver stress additionally adjusted for body mass index. Control models adjusted for age, sex, race/ethnicity, body mass index, hypertension, and smoking. CAC = coronary artery calcium; RA = rheumatoid arthritis; Adj = adjusted; OR = odds ratio; 95% CI = 95% confidence interval; IL-6 = interleukin-6; CRP = C-reactive protein; CES-D = Center for Epidemiologic Studies Depression Scale.
P values represent adjusted multiplicative (RA × psychosocial variable interaction terms) or additive interaction terms. ([RA + Psych + RA&Psych] − RA − Psych + 1) adjusted for age, sex, race, hypertension, body mass index, and smoking.
New adjusted OR after adding IL-6 (continuous) into overall adjusted models of psychosocial variables and CAC >100.
New adjusted OR after adding CRP (continuous) into overall adjusted models of psychosocial variables and CAC >100.