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 (chi 2(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, chi 2(108) = 204.071, p < .001, CFI = .972, RMSEA = .035, SRMR = .035. Blood pressure was associated with lower cognitive flexibility (beta = -.20, p < .001) and there was a significant indirect effect of age on episodic memory through cognitive flexibility (beta = .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.