TABLE 3.
Mediating Effect of Multiple Cerebrovascular or Degenerative Lesions on the Association of Diabetes with Cognitive Function
| Diabetes and Mediators | Memory Function, β (95% CI)a,b | Processing Speed, β (95% CI)a,b | Executive Function, β (95% CI)a,b |
|---|---|---|---|
| Markers of cerebrovascular disease as mediatorsc | |||
| Direct effect of diabetes | 0.001 (−0.075 to 0.078) | −0.068 (−0.137 to 0.000) | −0.059 (−0.120 to 0.002) |
| Mediating effects | |||
| Cortical infarcts | −0.011 (−0.020 to −0.004) | −0.012 (−0.023 to −0.004) | −0.006 (−0.012 to −0.002) |
| Subcortical infarcts | −0.007 (−0.014 to −0.002) | −0.008 (−0.017 to −0.002) | −0.005 (−0.010 to −0.000) |
| Cerebral microbleeds | |||
| A single cerebral microbleed | 0.000 (−0.001 to 0.003) | 0.000 (−0.001 to 0.003) | 0.000 (−0.001 to 0.002) |
| Multiple cerebral microbleeds | 0.000 (−0.004 to 0.003) | −0.002 (−0.007 to 0.001) | −0.002 (−0.006 to 0.001) |
| White matter lesion volume | −0.007 (−0.015 to −0.001) | −0.006 (−0.013 to −0.001) | −0.006 (−0.012 to −0.001) |
| Markers of brain atrophic lesions as mediatorsd | |||
| Direct effect of diabetes | −0.016 (−0.093 to 0.061) | −0.065 (−0.133 to 0.003) | −0.045 (−0.105 to 0.016) |
| Mediating effects | |||
| Gray matter volume | −0.014 (−0.026 to −0.004) | −0.017 (−0.030 to −0.006) | −0.013 (−0.024 to −0.004) |
| Normal white matter volume | 0.006 (−0.002 to 0.017) | −0.016 (−0.027 to −0.007) | −0.019 (−0.030 to −0.010) |
β and 95% confidence interval (CI) were derived from the mediation models, controlling for age, sex, education, smoking, and midlife hypertension.
β of direct effect of diabetes was the coefficient for an association of diabetes with cognition, after taking into account the effects of multiple mediators; β of mediating effect was the coefficient for an association of diabetes with cognition that was mediated by the mediator.
Multiple markers of cerebrovascular disease (cortical infarcts, subcortical infarcts, cerebral microbleeds, and white matter lesions) were simultaneously entered into the mediation model.
Multiple markers of brain atrophic lesions (gray matter and normal white matter volumes) were simultaneously entered into the mediation model.