Investigating the autonomic nervous system and cognitive functions as potential mediators of an association between cardiovascular disease and driving performance

Abstract: Cardiovascular disease (CVD) impacts the autonomic nervous system and cognitive functions related to activities of daily living, including driving an automobile. Although CVD has been linked to unsafe driving, mechanisms underlying this relationship remain elusive. The aim of this study was to examine the role of cognitive functions and the autonomic nervous system as potential mediators of driving performance. Nineteen individuals having recently suffered a cardiac event and sixteen individuals with no history of CVD completed a simulated drive using a STISIM simulator to assess driving performance. Heart rate was recorded throughout testing using a Polar RS800CX heart rate monitor and measures of executive, orienting and alerting functions were obtained through the Attention Network Test. We used the Baron and Kenny analysis method to assess potential mediating effects of the relationship between CVD and driving performance. Executive function was the only potential mediator investigated to be associated with driving (p < 0.01) and CVD (p < 0.05), however, it did not appear to play a mediating role (p = 0.28). These results suggest that individuals with CVD exhibit decrements in complex cognitive tasks such as driving and that further research is needed to better understand the mechanisms underlying this relationship

Achieving Canadian Physical Activity Guidelines is Associated with Better Vascular Function Independent of Aerobic Fitness and Sedentary Time in Older Adults.

Canadian physical activity guidelines recommend older adults accumulate 150 minutes of weekly moderate-vigorous physical activity (MVPA). Older adults who are insufficiently active may have reduced blood vessel health and an increased risk of cardiovascular disease. We tested this hypothesis in 11 older adults who did (7♀; 65±5 years; MVPA=239±81 minutes/week) and 10 older adults who did not (7♀; 68±9 years; MVPA=95±33 minutes/week) meet MVPA guidelines. Flow-mediated dilation (FMD) in the brachial (BA) and popliteal (POP) arteries, as well as, nitroglycerin-mediated dilation (NMD; endothelial-independent dilation) in the POP were assessed via ultrasonography. Aerobic fitness (VO2peak) was determined using a graded, maximal cycle ergometry test via indirect calorimetry. MVPA and sedentary time were assessed over five days using the PiezoRx® and activPAL®, respectively. There were no differences in VO2peak (26±10 versus 22±10 mlO2/kg/min; p=0.26) or sedentary time (512±64 versus 517±76 minutes/day; p=0.87) between groups; however, those who achieved the MVPA guidelines had a higher BA-FMD (5.1±1.3% versus 3.6±1.7%; p=0.03), POP-FMD (2.6±1.1% versus 1.3±0.8%; p=0.006) and POP-NMD (5.1±1.7% versus 3.3±2.1%; p=0.04). In the pooled sample, MVPA was moderately-correlated to both BA-FMD (r=0.53; p=0.01) and POP-NMD (r=0.59; p=0.005), and strongly-correlated to POP-FMD (r=0.85; pThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author