Table 2.

The interaction between aging, obesity, APOE4 with cognitive outcomes.

Author	Design	Age	ApoE4 effect
Ghebranious et al. (2011)	Cross-sectional (302 controls, APOE4 18% and 150 AD cases, APOE4 60%)	BMI at age 50. Age of assessment was 87 in cases and 78 in controls	Obesity at age 50 was associated with increased AD risk in APOE4 carriers
Zade et al. (2013)	Cross-sectional (general population, n = 1,969, 21% APOE4 carriers)	40–79, mean age 61	APOE4 with greater waist to hip ratio was associated lower measures of executive function and white matter hyperintensities
Rajan et al. (2014)	Longitudinal (n = 4,055), APOE4 34%. Interviewed at 3-year intervals for 19 years	Age > 65	Obesity and APOE4 showed slower cognitive decline
Backman et al. (2015)	Longitudinal N = 559; trajectories of BMI for 37 years	Age > 37	APOE4 was associated with a steeper decline in BMI and greater AD incidence