Table 3.
Path Coefficients from the Structural Equation Model of Cholinergic-Associated WMHV, Alzheimer’s Disease-Signature Cortical Thickness (AD-Sig CT), and Change in Domain-Specific Cognitive Performance (Domains Modeled Separately)*
| Independent Latent Variable | Standardized Loading | SE | p | |
|---|---|---|---|---|
| Change in Episodic Memory | ||||
| Direct Effects | Cholinergic WMHV | −0.05 | 0.07 | .433 |
| AD-Sig. CT | 0.09 | 0.06 | .127 | |
| Indirect Effect | Chol. WMHV → AD-Sig. CT | −0.01 | 0.01 | .130 |
| Change in Semantic Memory | ||||
| Direct Effects | Cholinergic WMHV | −0.24 | 0.09 | .011 |
| AD-Sig. CT | −0.11 | 0.09 | .205 | |
| Indirect Effect | Chol. WMHV → AD-Sig. CT | 0.02 | 0.01 | .244 |
| Change in Processing Speed | ||||
| Direct Effects | Cholinergic WMHV | −0.28 | 0.09 | .003 |
| AD-Sig. CT | 0.21 | 0.09 | .017 | |
| Indirect Effect | Chol. WMHV → AD-Sig. CT | −0.03 | 0.02 | .040 |
| Change in Executive Function | ||||
| Direct Effects | Cholinergic WMHV | −0.15 | 0.40 | .709 |
| AD-Sig. CT | 0.10 | 0.39 | .798 | |
| Indirect Effect | Chol. WMHV → AD-Sig. CT | −0.02 | 0.06 | .798 |
Note: WMHV = White matter hyperintensity volume.
*SE = standard error. Model fit statistics for episodic memory: Chi-square test: X2 = 638.98, df = 374, p < .0001; X2/df = 1.71; CFI = 0.96; TLI = 0.95; RMSEA (90% CI) = 0.032 (0.28, 0.036); SRMR = 0.056. Model fit statistics for semantic memory: Chi-square test: X2 = 774.15, df = 372, p < .0001; X2/df = 2.08; CFI = 0.92; TLI = 0.91; RMSEA (90% CI) = 0.041 (0.037, 0.045); SRMR = 0.056. Model fit statistics for processing speed: Chi-square test: X2 = 595.74, df = 320, p < .0001; X2/df = 1.86; CFI = 0.95; TLI = 0.94; RMSEA (90% CI) = 0.036 (0.031, 0.040); SRMR = 0.048. Model fit statistics for executive function: Chi-square test: X2 = 513.02, df = 320, p < .0001; X2/df = 1.60; CFI = 0.96; TLI = 0.95; RMSEA (90% CI) = 0.032 (0.027, 0.037); SRMR = 0.042. Paths from covariates (age at baseline, years of education, total intracranial volume, male gender, Hispanic ethnicity, and Black race) to latent variables were added to the model, and those with statistically significant loadings (p < .05) were retained.