Frequency of Mentally Stimulating Activities Modifies the Relationship Between Cardiovascular Reactivity and Executive Function in Old Age

Objectives Recent evidence suggests that younger and middle-age adults who show greater cardiovascular reactivity (CVR) to acute mental stress demonstrate better reasoning and memory skills. The purpose of this study was to examine whether older adults would exhibit a similar positive association between CVR and executive function and whether regular engagement in mentally stimulating activities (MSA) would moderate this association. Design Secondary cross-sectional analysis. Setting Three clinical research centers in the Midwest and on the West Coast and East Coast. Participants A total of 487 older adults participating in an ongoing national survey. Measurements Heart rate (HR) and low-frequency (LF) and high-frequency (HF) domains of heart rate variability (HRV) were measured at baseline and in response to standard mental stress tasks (Stroop color word task and mental arithmetic). Executive function was measured separately from the stress tasks by using five neuropsychological tests. MSA was measured by self-reported frequency of six common MSA. Results Higher HR reactivity was associated with better executive function after controlling for demographic and health characteristics and baseline HR, and the interaction between HR reactivity and MSA was significant for executive function. Higher LF-HRV reactivity was also associated with executive function, but subsequent analyses indicated that frequency of MSA was the strongest predictor of executive function in models that included LF-HRV or HF-HRV. Conclusions Higher HR reactivity to acute psychological stress is related to better executive function in older adults. For those with lower HR reactivity, engaging frequently in MSA produced compensatory benefits for executive function.