Table 2.
Linear Regression Results Assessing Relationship Between Z Score of Candidate Biomarker at Baseline and Change in Target to Background Ratio in the TARGET Trial Cohort With Increasing Adjustment
| Biomarker | All biomarkers only, β estimate (95% CI) | Baseline PCE only, β estimate (95% CI) | All biomarkers+PCE+ baseline TBR, β estimate (95% CI) | Selected biomarkers+ PCE+baseline TBR, β estimate (95% CI) |
|---|---|---|---|---|
| Cytokine/inflammation | ||||
| IL‐6 | 0.04 (−0.09 to 0.17) | … | 0.04 (−0.09 to 0.17) | … |
| sTNFR1 | −0.10 (−0.23 to 0.02)* | … | −0.12 (−0.25 to 0.01)* , ‡ | −0.09 (−0.18 to 0.00)* , ‡ |
| SAA | −0.17 (−0.35 to 0.00)* | … | −0.17 (−0.34 to 0.01)* , ‡ | −0.19 (−0.36 to −0.03)† , ‡ |
| hsCRP | 0.17 (−0.03 to 0.36)* | … | 0.16 (−0.04 to 0.36)* , ‡ | 0.22 (0.06 to 0.39)† , ‡ |
| CD‐40 ligand | −0.07 (−0.19 to 0.05) | … | −0.05 (−0.19 to 0.09) | … |
| Adipokines | ||||
| Adiponectin | −0.12 (−0.22 to −0.01)† , ‡ | … | −0.13 (−0.24 to −0.02)* , ‡ | −0.06 (−0.15,0.02)* , ‡ |
| Leptin | −0.03 (−0.13 to 0.08) | … | −0.02 (−0.13 to 0.09) | … |
| Resistin | 0.07 (−0.03 to 0.18) | … | 0.09 (−0.02 to 0.20) | … |
| Atherothrombosis | ||||
| Antithrombin III | 0.04 (−0.07 to 0.15) | … | 0.04 (−0.08 to 0.16) | … |
| PAI‐1 | −0.05 (−0.17 to 0.07) | … | −0.05 (−0.18 to 0.08) | … |
| Lipids parameters | ||||
| Apolipoprotein A1 | 0.07 (−0.05 to 0.18) | … | 0.06 (−0.06 to 0.18) | … |
| Apolipoprotein A2 | 0.02 (−0.13 to 0.18) | … | 0.02 (−0.15 to 0.18) | … |
| Apolipoprotein B | 0.02 (−0.09 to 0.13) | … | 0.01 (−0.11 to 0.14) | … |
| Apolipoprotein C1 | 0.02 (−0.14 to 0.17) | … | 0.03 (−0.14 to 0.19) | … |
| Apolipoprotein C3 | −0.02 (−0.14 to 0.10) | … | −0.03 (−0.16 to 0.09) | … |
| Apolipoprotein H | −0.05 (−0.18 to 0.08) | … | −0.05 (−0.18 to 0.09) | … |
| Lp(a) | 0.03 (−0.06 to 0.12) | … | 0.03 (−0.07 to 0.13) | … |
| LDL | −0.04 (−0.14 to 0.07) | … | −0.04 (−0.16 to 0.07) | … |
| Other analytes | ||||
| hsTnT | −0.11 (−0.32 to 0.11) | … | −0.11 (−0.34 to 0.12) | … |
| NT‐proBNP | 0.04 (−0.06 to 0.13) | … | 0.04 (−0.08 to 0.15) | … |
| VCAM‐1 | 0.04 (−0.07 to 0.16) | … | 0.05 (−0.08 to 0.17) | … |
| VEGF‐A | −0.02 (−0.13 to 0.08) | … | −0.01 (−0.13 to 0.10) | … |
| MMP‐1 | −0.02 (−0.12 to 0.08) | … | −0.02 (−0.12 to 0.08) | … |
| MMP‐3 | 0.08 (−0.04 to 0.20) | … | 0.08 (−0.04 to 0.20) | … |
| YKL‐40 | 0.15 (0.05 to 0.25)† | … | 0.15 (0.04 to 0.26)† , ‡ | 0.11 (0.02 to 0.20)† , ‡ |
| Cystatin‐C | −0.04 (−0.14 to 0.06) | … | −0.05 (−0.17 to 0.06) | … |
| Osteopontin | −0.03 (−0.13 to 0.07) | … | −0.02 (−0.13 to 0.10) | … |
| Osteoprotegrin | −0.09 (−0.20 to 0.01)* | … | −0.09 (−0.20 to 0.02)* , ‡ | −0.12 (−0.20 to −0.03)* , ‡ |
| Pooled cohort equation | … | 0.00 (−0.02 to 0.01) | 0.00 (−0.02 to 0.02) | 0.01 (−0.01 to 0.02) |
| Model fit statistics | ||||
| Adjusted R 2 | 0.35 | 0.20 | 0.32 | 0.32 |
| RMSE | 0.349 | 0.450 | 0.352 | 0.401 |
| AIC | 141.9 | 139.7 | 143.3 | 127.3 |
| BIC | 225.3 | 150.4 | 228.5 | 153.9 |
All models include the baseline target to background ratios values from the most diseased segment (TBR MDS). PCE includes as predictor variables age, sex, race, diabetes status, cigarette use, systolic blood pressure, treatment for hypertension, total and high‐density lipoprotein cholesterol values. R 2 indicates better model fit when larger and RMSE is better when smaller. The variance inflation factors across all models were <5, which signifies low (or no) collinearity. AIC indicates Akaike information criterion; BIC, Bayesian information criterion; CT, computed tomography; FDG, fluorodeoxyglucose; hsCRP, high‐sensitivity C‐reactive protein; hsTnT, high sensitivity troponin T; IL, interleukin; LDL, low‐density lipoprotein; Lp(a), lipoprotein(a); MDS, most diseased segment; MMP‐1, matrix metalloproteinase 1; MMP‐3, matrix metalloproteinase 3; NT‐proBNP, N‐terminal pro‐B‐type natriuretic peptide; PAI‐1, plasminogen activator inhibitor‐1; PCE, pooled cohort equation; PET, positron emission tomography; RA, rheumatoid arthritis; RMSE, root mean square error; SAA, serum amyloid A; sTNFR1, soluble tumor necrosis factor receptor 1; TARGET, Treatments Against RA and Effect on FDG PET/CT; TBR, target to background ratio; VCAM‐1, vascular cell adhesion molecule 1; and VEGF‐A, vascular endothelial growth factor A.
P<0.10.
P<0.01.
Values have P≤0.10 and were advanced to the selected biomarkers model (right column).