Lifestyle and Neurocognition in Older Adults With Cardiovascular Risk Factors and Cognitive Impairment

Abstract

Objective: The aim of the study was to determine the relationship of lifestyle factors and neurocognitive functioning in older adults with vascular risk factors and cognitive impairment, no dementia (CIND).

Methods: One hundred sixty adults (M [SD] = 65.4 [6.8] years) with CIND completed neurocognitive assessments of executive function, processing speed, and memory. Objective measures of physical activity using accelerometry, aerobic capacity determined by exercise testing, and dietary habits quantified by the Food Frequency Questionnaire and 4-Day Food Diary to assess adherence to the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets were obtained to assess direct effects with neurocognition. Potential indirect associations of high-sensitivity C-reactive protein and the Framingham Stroke Risk Profile also were examined.

Results: Greater aerobic capacity (β = 0.24) and daily physical activity (β = 0.15) were associated with better executive functioning/processing speed and verbal memory (βs = 0.24; 0.16). Adherence to the DASH diet was associated with better verbal memory (β = 0.17). Greater high-sensitivity C-reactive protein (βs = -0.14; -0.21) and Framingham Stroke Risk Profile (β = -0.18; -0.18) were associated with poorer executive functioning/processing speed and verbal memory. Greater stroke risk partially mediated the association of aerobic capacity with executive functioning/processing speed, and verbal memory and greater inflammation partially mediated the association of physical activity and aerobic fitness, with verbal memory.

Conclusions: Higher levels of physical activity, aerobic fitness, and adherence to the DASH diet are associated with better neurocognitive performance in adults with CIND. These findings suggest that the adoption of healthy lifestyle habits could reduce the risk of neurocognitive decline in vulnerable older adults.

Clinical trial registration: NCT01573546.

Figure 1

Indirect associations between aerobic fitness, stroke risk, inflammation, and Executive Function and Processing Speed. Values represent the standardized beta coefficients from separate models examining the indirect associations of hsCRP (inflammation) and the Framingham Stroke Risk Profile (stroke risk) on neurocognition. Within each model, parameter estimates from individual predictive models are denoted with β and parameters from the final model including all predictors are denoted with β’. As show, the association between aerobic fitness and Executive Function and Processing Speed remained significant in both models. The association between hsCRP and Executive Function and Processing Speed was attenuated and examination of the bootstrapped estimates of the indirect effect indicated that hsCRP was not a significant mediator of the aerobic fitness and Executive Function and Processing Speed association (direct effect = 0.17 [−0.01, 0.36]; indirect effect = 0.03 [−0.02, 0.10]). The association between stroke risk and Executive Function and Processing Speed tended to be attenuated and examination of the bootstrapped estimates of the indirect effect indicated that stroke risk was not a significant mediator of the aerobic fitness and Executive Function and Processing Speed association (direct effect = 0.20 [0.02, 0.38]; indirect effects: 0.03 [−0.01, 0.10]).). Taken together, the pattern of findings suggested stroke risk partially mediated the association between aerobic fitness and Executive Function and Processing Speed, whereas inflammation did not.

Figure 2

Indirect associations between physical activity, inflammation, and Verbal Memory. Values represent standardized beta coefficients. Within each model, parameter estimates from individual predictive models are denoted with β and parameters from the final model including all predictors are denoted with β’. As show, the association between physical activity and verbal memory was modestly attenuated in a final model incorporating inflammation, although the bootstrapped estimates of the indirect effect indicated that hsCRP was not a significant mediator of the physical activity and Verbal Memory association (direct effect = 0.12 [−0.02, 0.27]; indirect effect = 0.03 [−0.001, 0.07]).