Association of cardiometabolic health factors with age-related executive function and episodic memory.

Although decline of cognitive abilities in late life is regarded as a common facet of aging, there is inter-individual variability in this decline. Possible contributors are cardiometabolic risk factors associated with cerebrovascular dysfunction, but a dearth in unifying health-cognition models confound exactly how these risk factors mediate age-related changes in executive function (EF) and episodic memory. This study investigated the indirect effect of age on these cognitive abilities via cardiometabolic risk factors using a structural equation modeling approach. Participants included 738 adults (64% female) ranging from 21 to 85 years of age (M = 47.47, SD = 18.28). An exploratory factor analysis was applied to an EF battery yielding a two-factor solution, consisting of inhibition and cognitive flexibility, that showed acceptable fit (χ2(48) = 101.84, p < .001, CFI = .980, RMSEA = .039, SRMR = .035). The EF latent factors were then included in a confirmatory factor analysis exploring the indirect role of age on episodic memory and EF via blood pressure, cholesterol, triglycerides and body mass index. The theoretical model demonstrated acceptable fit, χ2(108) = 204.071, p < .001, CFI = .972, RMSEA = .035, SRMR = .035. Blood pressure was associated with lower cognitive flexibility (β = -.20, p < .001) and there was a significant indirect effect of age on episodic memory through cognitive flexibility (β = .07, p = .021). Results support the "Executive Decline Hypothesis" of age-related episodic memory decline and specifically implicate lower blood pressure control and cognitive flexibility in these changes.