Marked gender differences in progression of mild cognitive impairment over 8 years.

Introduction: This study examined whether, among subjects with mild cognitive impairment (MCI), women progressed at faster rates than men.

Methods: We examine longitudinal rates of change from baseline in 398 MCI subjects (141 Females, 257 Males) in the Alzheimer's Disease Neuroimaging Initiative-1 (ADNI-1), followed for up to 8 years (mean 4.1±2.5 years) using mixed effects models incorporating all follow ups (mean 8±4 visits).

Results: Women progressed at faster rates than men on ADAS-Cog (p=0.001) and CDR-SB (p=0.003). Quadratic fit for change over time was significant for both ADAS-Cog (p=0.001) and CDR-SB (p=0.004), and the additional acceleration in women was 100% for ADAS-Cog and 143% for CDR-SB. The variability of change was greater in women. The gender effect was greater in ApoE4 carriers.

Discussion: Women with MCI have greater longitudinal rates of cognitive and functional progression than men. Studies to confirm and uncover potential mechanisms appear to be warranted.