Cardiovascular risk moderates the effect of aerobic exercise on executive functions in older adults with subcortical ischemic vascular cognitive impairment

Abstract

Aerobic training (AT) can promote cognitive function in adults with Subcortical Ischemic Vascular Cognitive Impairment (SIVCI) by modifying cardiovascular risk factors. However, pre-existing cardiovascular health may attenuate the benefits of AT on cognitive outcomes in SIVCI. We examined whether baseline cardiovascular risk moderates the effect of a 6-month progressive AT program on executive functions with a secondary analysis of a randomized controlled trial in 71 adults, who were randomized to either: (1) 3×/week progressive AT; or (2) education program (CON). Three executive processes were measured: (1) response inhibition by Stroop Test; (2) working memory by digits backward test; and (3) set shifting by the Trail Making Test. Baseline cardiovascular risk was calculated using the Framingham cardiovascular disease (CVD) Risk Score (FCRS), and participants were classified as either low risk (< 20% FCRS score; LCVR) or high risk (≥ 20% FCRS score; HCVR). A complete case analysis (n = 58) was conducted using an analysis of covariance (ANCOVA) to evaluate between-group differences in the three executive processes. A significant interaction was found between cardiovascular risk group and intervention group (AT or CON) for the digit span backward and the Trail Making Test. AT improved performance compared with CON in those with LCVR, while in those with HCVR, AT did not improve performance compared with CON. Baseline cardiovascular risk significantly moderates the efficacy of AT on cognition. Our findings highlight the importance of intervening early in the disease course of SIVCI, when cardiovascular risk may be lower, to reap maximum benefits of aerobic exercise.

Conflict of interest statement

The authors declare no competing interests.

© 2021. The Author(s).

Figures

Figure 1

Interaction between cardiovascular risk (CVR) group (low CVR, high CVR) and experimental group (control, aerobic training) on the three tests of executive function at trial completion, controlling for baseline performance on the test, age, baseline MoCA score, and education. (A) Estimated mean (+ SEM) total number correct on the Verbal digits backward test at trial completion, with a significant interaction between cardiovascular risk group and experimental group (p < 0.037), suggesting that aerobic training improved the total number of correct responses compared to control in the low CVR participants but not in the high CVR participants. (B) Estimated mean (+ SEM) time to complete the Trail-Making tests (Part B minus Part A; seconds) at trial completion, with a significant interaction between cardiovascular risk group and experimental group (p < 0.048), suggesting that aerobic training improved performance compared to control in the low CVR participants but not in the high CVR participants. (C) Estimated mean (+ SEM) time to complete the Stroop test at trial completion, with no significant interaction between cardiovascular risk group and experimental group (p > 0.819), suggesting that aerobic training not influence performance compared to control in either the low CVR or high CVR participants.