Cognitive Performance and Incident Alzheimer's Dementia in Men Versus Women
Ioannis Liampas, Vasileios Siokas, C. G. Lyketsos, Efthimios Dardiotis
Abstract
BACKGROUND: The utility of neuropsychological measurements as forerunners of Alzheimer's Disease Dementia (AD) in individuals with normal cognition or mild cognitive impairment (MCI) is undeniable. OBJECTIVES: To assess the differential prognostic value of cognitive performance in older men versus women. DESIGN: Longitudinal analysis of data acquired from the National Alzheimer's Coordinating Center Uniform Data Set. SETTINGS: Data on older adults (≥60 years) were derived from 43 National Institute on Aging - funded Alzheimer's Disease Research Centers. PARTICIPANTS: 10,073 cognitively unimpaired (CU) older adults followed for 5.5±3.8 years and 3,925 participants with amnestic MCI monitored for 3.5±2.8 years. MEASUREMENTS: The domains of episodic memory, verbal fluency, naming, attention, processing speed and executive function were assessed. Cox proportional hazards models examined associations between individual cognitive domains and AD incidence separately for each participant set. CU and MCI. These predictive models featured individual neuropsychological measures, sex, neuropsychological measure by sex interactions, as well as a number of crucial covariates. RESULTS: Episodic memory and verbal fluency were differentially related to future AD among CU individuals, explaining a larger proportion of risk variance in women compared to men. On the other hand, naming, attention and executive function were differentially related to future AD among participants with MCI, accounting for a greater fraction of risk variance in men than women. CONCLUSION: Cognitive performance is differentially related to risk of progressing to AD in men versus women without dementia.