Figure 3.

Mediation effects of brain MRI markers in the associations of baseline plasma ET levels with global cognitive decline. Causal mediation analyses of the total mediating effects (95% CI) of WMH (A), global cortical thickness (B), and hippocampus volume (C) are reported when there was a statistically significant mediation, as estimated by the difference between the total (path c) and direct (path c’) effect of plasma ET on cognitive change (c-c′). The direct effect of plasma ET on cognition (c’) was estimated by adjusting the association between plasma ET and cognitive change (total effect, c) for the mediator. The direct effect of plasma ET on the imaging markers is designated path a, while the direct effect of these markers on cognition is path b. All paths were adjusted by age, gender, education, APOE ε4 status, hypertension, diabetes, cardiovascular disease, and total intracranial volume. Abbreviations: CI = confidence interval, ET = ergothioneine, WMH = white matter hyperintensities.