Sex-Related Reserve Hypothesis in Alzheimer’s Disease: Changes in Cortical Thickness with a Five-Year Longitudinal Follow-Up

Background: Sex effects on the progression of Alzheimer’s disease (AD) have received less attention than other demographic factors, including onset age and education. Objective: The aim of this study was to investigate whether sex affected cortical thinning in the disease progression of AD. Methods: We prospectively recruited 36 patients with early-stage AD and 14 people with normal cognition. All subjects were assessed with magnetic resonance imaging at baseline, Year 1, Year 3, and Year 5. We performed cortical thickness analyses using surface-based morphometry on magnetic resonance imaging. Results: Women with AD showed more rapid cortical thinning in the left dorsolateral frontal cortex, left superior temporal gyrus, bilateral temporo-parietal association cortices, bilateral anterior cingulate gyri, bilateral medial frontal cortices, and bilateral occipital cortices over 5 years than men with AD, even though there was no difference in cortical thickness at baseline. In contrast, there were no regions of significantly more rapid atrophy in men with AD. Conclusions: Our findings suggest that women deteriorate faster than men in the progression of AD.