P4-019: Influence of educational attainment and occupation on relationships that cognitive function has with MRI-based neuropathology, mild cognitive impairment, and dementia: Results from the Women's Health Initiative Memory Study

The cognitive reserve hypothesis predicts that greater education and increased intellectual stimulation preserve cognitive function. 7,479 women, aged 65–80 and free of dementia at enrollment in the Women's Health Initiative Memory Study, were followed annually with tests of global cognitive function and central adjudication for probable dementia and mild cognitive impairment. More comprehensive annual cognitive testing was conducted in a subset of 2,303 women. Standardized magnetic resonance imaging (MRI) was used to assess ischemic lesion volume and total brain volume in 1,403 of the women, an average of 7.0 years after enrollment, which were used as markers of neuropathology. After covariate-adjustment to align women with respect to level of MRI-based neuropathology, those reporting greater levels of education and higher job classifications scored better on tests of cognitive function (p<0.001). Among women with elevated ischemic lesion volume and lower brain volume, higher education was associated with less cognitive decline in the five years preceding their MRI (p=0.03). For women without elevated neuropathology, 5-year changes in cognition were modest and unrelated to education. In the ±3 years spanning conversion to dementia and/or mild cognitive impairment, more highly educated women had more precipitous declines in cognitive function (p<0.001). Higher levels of education and intellectual stimulation may increase the time women are able cognitively to withstand the progression of neuropathology.