Effects of aerobic exercise on mental stress-induced arterial stiffness in black young adults

Thumbnail Image
Johnson, Lakeisha H.
Harber, Matthew P.
Issue Date
Thesis (M.S.)
Other Identifiers
CardCat URL

Black populations account for the highest rates of cardiovascular disease (CVD) mortality, morbidity, and subclinical indices of CVD. Studies support that there are ethnic disparities in arterial stiffness, particularly manifested as early vascular aging. While ethnic disparities cannot be solely explained by traditional CVD risk factors, psychosocial factors, such as mental stress, have correlated to increased arterial stiffness. Exercise has been mentioned as a notable therapeutic mechanism for stressrelated stiffness. Thus, the purpose of this study was to determine the effects of an acute bout of moderate-intensity aerobic exercise on mental stress-induced arterial stiffness in Black young adults. METHODS: 10 apparently healthy individuals (4 male, 6 female, 22.0 ± 1.8 years and BMI 25.3 ± 3.6 kg/m2) performed 30 minutes of treadmill exercise at 64-76% of heart rate maximum before a 5-minute mental stress task. Arterial stiffness (measured as carotid femoral pulse wave velocity [cfPWV]) and brachial and central hemodynamic measures (bSBP, bDBP, bPP, cSBP, cDBP, cPP, MAP, HR, AP, AIx, AIx@75) were recorded before and after the task and compared to results gathered on the control day (consisting of the same mental stress task without prior exercise). Participants were randomly assigned to either the control or exercise trial first. RESULTS: The mental stress task increased PWV, independent of exercise (main effect for time, p < 0.001). The absolute change in PWV from pre to post 0 minutes was similar (p > 0.05) for control (+0.43±0.39) and exercise (+0.33±0.70) trials. Mental stress had a main effect for time (p < 0.05) in emotional responses from before and after mental stress task in both the control and exercise trials for anger, anxiety, and overall perceived negative emotional responses. DISCUSSION: Exercise had no effect on preventing or reducing the mental stress-induced increases in arterial stiffness and negative emotional responses. Data reflect blunted vasodilatory response previously observed in the Black population. Therefore, this study echoes the CV reactivity differences demonstrated in prior literature, emphasizing concern for CV outcomes in this specific population.