Abdominal obesity and chronic stress interact to predict blunted cardiovascular reactivity

Abdominal obesity and chronic stress have independent effects on cardiac autonomic regulation, and may also interact to influence cardiovascular reactivity. In addition to main effects, we hypothesized that abdominal obesity and chronic stress would interact and predict blunted cardiovascular reactivity. One hundred and twenty-two undergraduate students engaged in two stressful laboratory tasks while cardiovascular activity was assessed. Results indicated that higher abdominal obesity significantly predicted blunted systolic blood pressure (SBP) and mean arterial pressure (MAP) change, while chronic stress was not directly associated with any measure of cardiovascular reactivity. Furthermore, there was a significant interaction between abdominal obesity and chronic stress on SBP and MAP change such that among participants with higher chronic stress, higher abdominal obesity was significantly associated with reduced SBP and MAP reactivity. In addition, body-mass index (BMI), a measure of overall obesity, also had both main and interaction effects with chronic stress to predict blunted cardiovascular reactivity. These results suggest that abdominally obese individuals may incur difficulty in mounting appropriately-sized cardiovascular responses during acute stress, particularly when under high levels of chronic stress.