LEP and Alzheimer disease: These results must be interpreted with caution and deserve further investigation; however, they are, to some extent, consistent with the U-shaped association between BMI and lower cognitive function in late midlife reported in the Chicago Health and Aging Project (CHAP) study [35], and they seem to support the notion that lower cognitive function in midlife may lead to weight loss (and hence lower BMI), consistent with the previously reported association between Alzheimer’s disease and leptin, which promotes weight loss [39].