Cognitive reserve in relation to abeta42 in patients converting from MCI to dementia - a follow-up report.

UNLABELLED: The concept of the cognitive reserve (CR) hypothesizes that premorbid factors such as education enable compensation for the manifestation of brain pathology. Accordingly, pathology should be more prominent in individuals with higher CR before becoming clinically apparent. Previously, we found that patients subsequently converting to dementia with higher CR had lower concentrations of amyloid beta 42 (abeta42) as compared to patients with lower CR. However, the interaction between time, biomarkers, neuropsychological performance and CR is yet to be established. OBJECTIVE: To study the relation between biomarkers, neuropsychological performance and CR longitudinally. METHOD: A mixed between-within subject analysis of variance was performed for longitudinal analysis. Paired t tests were used for within group comparisons. RESULTS: Patients with higher CR (n = 15) had significantly lower concentrations of abeta42 at both time points compared to those with medium (n = 23) and lower CR (n = 28). Also, abeta42 concentrations decreased significantly from baseline to follow-up in patients with higher and medium CR. Groups performed comparably on neuropsychological tests. CONCLUSION: This study provides further support for the applicability of abeta42 as a substitute for pathology in relation to CR. Also, abeta42 reflects the disease progression in patients with higher and medium CR.