An age-related decline in cognitive performance and brain structure among cognitively normal individuals is greater in men than women, but not associated with APOE ε4, according to a cross-sectional observational study of 1,246 adults without dementia or Alzheimer disease.
Researchers compared age, sex, and APOE ε4 effects on memory, brain structure, and amyloid positron emission tomography (PET) in subjects ages 30 to 90 and found:
• Memory declines from age 30 to 90 years, and is worse in men than women, especially after age 40.
• From age 30 to mid-60s, adjusted hippocampal volume (HVa) gradually worsens before sharper declines thereafter, and is lower in men than women overall.
• APOE ε4 status did not impact memory performance or HVa at any age, however, from age 70 onward, APOE ε4 carriers had significantly greater median amyloid PET than noncarriers.
• Ten percent of the population is positive for amyloid PET at age 57 for APOE ε4 carriers and 64 for noncarriers.
Citation: Jack CR Jr, Wiste HJ, Weigand SD, et al. Age, sex, and APOE ε4 effects on memory, brain structure, and β-amyloid across the adult life span. JAMA Neurol. 2015. doi: 10.1001/jamaneurol.2014.4821.