Table 4.
Association between inflammatory biomarkers and brain structural MRI measures.
| Brain MRI measure | Biomarker continuous or quartiles | CRP | IL6 | ACT | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
| ||||||||||
| N | b | p | N | b | p | N | b | p | ||
|
| ||||||||||
| Model 1: adjusted for age at time of scan, gender, ethnicity/race | ||||||||||
|
| ||||||||||
| TBV | Continuous Q4 vs. Q1 trend of quartiles | 508 | -4.13 | 0.008 | 357 | -15.01 | <0.0001 | 435 | -6.83 | 0.454 |
| -19.91 | 0.010 | -31.18 | 0.001 | -0.36 | 0.970 | |||||
| -5.89 | 0.016 | -11.93 | <0.0001 | -2.00 | 0.454 | |||||
|
| ||||||||||
| TGMV | Continuous Q4 vs. Q1 trend of quartiles | 508 | -2.42 | 0.003 | 357 | -6.61 | 0.001 | 435 | -5.97 | 0.218 |
| -11.02 | 0.006 | -10.56 | 0.034 | -1.99 | 0.658 | |||||
| -3.82 | 0.003 | -4.63 | 0.004 | -1.75 | 0.220 | |||||
|
| ||||||||||
| TWMV | Continuous Q4 vs. Q1 trend of quartiles | 508 | -2.36 | 0.023 | 357 | -7.58 | 0.004 | 435 | -8.94 | 0.142 |
| -9.87 | 0.056 | -16.17 | 0.011 | -1.21 | 0.830 | |||||
| -2.86 | 0.081 | -5.70 | 0.005 | -1.88 | 0.293 | |||||
|
| ||||||||||
| CT | Continuous Q4 vs. Q1 | 508 | -0.008 | 0.004 | 357 | -0.006 | 0.333 | 435 | -0.042 | 0.007 |
| -0.034 | 0.010 | -0.007 | 0.655 | -0.030 | 0.030 | |||||
| -0.012 | 0.005 | -0.004 | 0.390 | -0.010 | 0.021 | |||||
|
| ||||||||||
| mean FA | Continuous Q4 vs. Q1 trend of quartiles | 183 | -0.001 | 0.328 | 129 | -0.004 | 0.119 | 154 | -0.003 | 0.663 |
| -0.004 | 0.374 | -0.007 | 0.210 | 0.001 | 0.822 | |||||
| -0.001 | 0.497 | -0.002 | 0.260 | 0.001 | 0.684 | |||||
|
| ||||||||||
| Model 2: adjusted for age at time of scan, gender, ethnicity/race, APOE status, and ICV | ||||||||||
|
| ||||||||||
| TBV | Continuous Q4 vs. Q1 trend of quartiles | 508 | -4.31 | 0.006 | 357 | -14.96 | <0.0001 | 435 | -6.99 | 0.443 |
| -20.49 | 0.008 | -31.02 | 0.001 | -0.54 | 0.949 | |||||
| -6.14 | 0.014 | -11.89 | <0.0001 | -2.04 | 0.441 | |||||
|
| ||||||||||
| TGMV | Continuous Q4 vs. Q1 trend of quartiles | 508 | -2.48 | 0.002 | 357 | -6.52 | 0.002 | 435 | -5.89 | 0.224 |
| -11.97 | 0.003 | -10.35 | 0.038 | -1.95 | 0.66 | |||||
| -3.91 | 0.002 | -4.57 | 0.004 | -1.73 | 0.226 | |||||
|
| ||||||||||
| TWMV | Continuous Q4 vs. Q1 trend of quartiles | 508 | -2.39 | 0.023 | 357 | -7.47 | 0.004 | 435 | -8.93 | 0.143 |
| -9.92 | 0.056 | -16.04 | 0.012 | -1.20 | 0.831 | |||||
| -2.83 | 0.082 | -5.63 | 0.005 | -1.88 | 0.295 | |||||
|
| ||||||||||
| CT | Continuous Q4 vs. Q1 trend of quartiles | 508 | -0.007 | 0.007 | 357 | -0.006 | 0.361 | 435 | -0.041 | 0.007 |
| -0.033 | 0.013 | -0.004 | 0.413 | -0.031 | 0.033 | |||||
| -0.011 | 0.008 | -0.004 | 0.462 | -0.010 | 0.023 | |||||
|
| ||||||||||
| mean FA | Continuous Q4 vs. Q1 trend of quartiles | 183 | -0.001 | 0.310 | 129 | -0.004 | 0.125 | 154 | -0.003 | 0.642 |
| -0.005 | 0.365 | -0.007 | 0.218 | 0.001 | 0.835 | |||||
| -0.001 | 0.476 | -0.002 | 0.268 | 0.001 | 0.671 | |||||
|
| ||||||||||
| Model 3: adjusted for age at time of scan, gender, ethnicity/race, APOE status, ICV, depression, BMI, smoking status, and vascular factors | ||||||||||
|
| ||||||||||
| TBV | Continuous Q4 vs. Q1 trend of quartiles | 447 | -2.17 | 0.229 | 324 | -14.33 | 0.001 | 393 | 1.44 | 0.832 |
| -8.99 | 0.308 | -32.46 | 0.001 | 8.32 | 0.349 | |||||
| -2.73 | 0.331 | -11.77 | <0.0001 | 0.39 | 0.891 | |||||
|
| ||||||||||
| TGMV | Continuous Q4 vs. Q1 trend of quartiles | 447 | -1.35 | 0.142 | 324 | -6.69 | 0.002 | 393 | -3.71 | 0.460 |
| -6.12 | 0.172 | -12.39 | 0.015 | 0.79 | 0.864 | |||||
| -2.11 | 0.140 | -4.93 | 0.002 | -1.13 | 0.441 | |||||
|
| ||||||||||
| TWMV | Continuous Q4 vs. Q1 trend of quartiles | 447 | -1.87 | 0.122 | 324 | -8.13 | 0.003 | 393 | -4.79 | 0.460 |
| -5.73 | 0.335 | -18.49 | 0.006 | 2.87 | 0.629 | |||||
| -1.75 | 0.352 | -6.37 | 0.003 | -0.88 | 0.641 | |||||
|
| ||||||||||
| CT | Continuous Q4 vs. Q1 trend of quartiles | 447 | -0.006 | 0.064 | 324 | -0.005 | 0.456 | 393 | -0.054 | 0.001 |
| -0.027 | 0.077 | -0.007 | 0.676 | -0.038 | 0.011 | |||||
| -0.010 | 0.045 | -0.004 | 0.515 | -0.013 | 0.006 | |||||
|
| ||||||||||
| mean FA | Continuous Q4 vs. Q1 trend of quartiles | 164 | 0.0001 | 0.880 | 118 | -0.003 | 0.294 | 141 | 0.000 | 0.985 |
| -0.0002 | 0.978 | -0.005 | 0.402 | 0.002 | 0.708 | |||||
| -0.0001 | 0.917 | -0.001 | 0.541 | -0.0001 | 0.827 | |||||
Results from regression models adjusted for age at time of scan, gender, ethnicity/race (Model 1), and then additionally adjusted for APOE status and ICV (Model 2), and finally adjusted for all the Model 2 variables and BMI, smoking status, and vascular factors (Model 3). Abbreviation: Apolipoprotein (APOE); C-reactive protein (CRP); cortical thickness (CT); fractional anisotropy (FA); interleukin-6 (IL6); intra-cranial volume (ICV); total brain volume (TBV); total gray matter volume (TGMV); total white matter volume (TWMV).
Q4 is the 4th (the highest) quartile, and Q1 the first (the lowest) quartile.
The trend tests were analyzed by entering the quartiles as an ordinal variable into the linear models.