Table 3.
Regression coefficients and significance levels (p-values) for associations between CETP polymorphisms and brain structure in a priori selected ROIs in females
| SNP | Diagnosis | APOE ε4 carrier status |
N | Entorhinal cortex thickness β (p-value) |
Parahippocampal gyrus thickness β (p-value) |
|---|---|---|---|---|---|
| C-629A | All | All | 506 | 0.047 (0.507) | 0.003 (0.966) |
| HC | All | 188 | 0.267 (0.023*) (A) | 0.250 (0.031*) (A) | |
| MCI, AD | All | 318 | −0.017 (0.850) | −0.118 (0.178) | |
| All | Non-carriers | 250 | 0.005 (0.956) | 0.040 (0.684) | |
| HC | Non-carriers | 135 | 0.098 (0.479) | 0.164 (0.224) | |
| MCI, AD | Non-carriers | 115 | −0.115 (0.439) | −0.128 (0.387) | |
| All | Carriers | 256 | 0.052 (0.606) | −0.096 (0.321) | |
| HC | Carriers | 53 | 0.547 (0.016*) (A) | 0.577 (0.020*) (A) | |
| MCI, AD | Carriers | 203 | 0.042 (0.703) | −0.135 (0.212) | |
| I405V | All | All | 506 | 0.088 (0.134) | 0.203 (0.686) |
| HC | All | 188 | 0.151 (0.115) | 0.242 (0.011*) (I) | |
| MCI, AD | All | 318 | 0.033 (0.658) | −0.125 (0.090) | |
| All | Non-carriers | 250 | 0.222 (0.007*) (I) | .0197 (0.016*) (I) | |
| HC | Non-carriers | 135 | 0.233 (0.032*) (I) | 0.256 (0.017*) (I) | |
| MCI, AD | Non-carriers | 115 | 0.100 (0.442) | 0.023 (0.861) | |
| All | Carriers | 256 | −0.076 (0.370) | −0.194 (0.018*) (V) | |
| HC | Carriers | 53 | −0.066 (0.741) | 0.236 (0.282) | |
| MCI, AD | Carriers | 203 | −0.061 (0.506) | −0.230 (0.011*) (V) |
Regression coefficients and significance levels were obtained from linear regression models in which CETP genotype was the independent variable and morphometric measures were the dependent variables. The valence assigned to β coefficients corresponds to the directionality of association. For CETP C-629A, positive values mean that the A allele is associated with greater volumes, and negative values mean that the C allele is associated with greater volumes. For CETP I405V, positive values mean that the I allele is associated with greater volumes, and negative values mean that the V allele is associated with greater volumes. CETP polymorphisms are associated with two morphometric measures in females, dependent upon diagnosis and APOE ε4 carrier status. No significant associations were detected with hippocampal volume in females. The only significant associations detected in males were between C-629A and hippocampal volume in MCI and AD carriers of APOE ε4 (β = .230; p = .017, protective allele = A); I405V and entorhinal cortex thickness in non-carriers of APOE ε4 (β = .165; p = .048, protective allele = I); and I405V and hippocampal volume in non-carriers of APOE ε4 (β = .176; p = .036, protective allele = I).
Statistically significant p-values (p < .05) are represented in bold, and the allele corresponding to greater thickness (i.e. the “protective” allele) is denoted in parentheses