Exercise reduces stress-related amygdala metabolic activity in obese women: A pilot 18F-FDG PET/CT study

초록

Introduction: Psychological stress is recognized as a significant contributor to the risk of cardiovascular disease (CVD). Chronic physical activity is acknowledged for its role in mitigating CVD risk, in part by diminishing psychological stress. The association between obesity and heightened psychological stress has been established. This study seeks to assess whether regular physical exercise can prospectively mitigate stress-related amygdala metabolic activity in women with obesity, utilizing 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT).Psychological stress is recognized as a significant contributor to the risk of cardiovascular disease (CVD). Chronic physical activity is acknowledged for its role in mitigating CVD risk, in part by diminishing psychological stress. The association between obesity and heightened psychological stress has been established. This study seeks to assess whether regular physical exercise can prospectively mitigate stress-related amygdala metabolic activity in women with obesity, utilizing 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Methods: This investigation involved the participation of 43 individuals. Specifically, 23 obese women engaged in a regimen of physical exercise five days per week over a span of three months. The exercise regimen encompassed both aerobic exercise and resistance training. Serial 18F-FDG PET/CT scans were conducted at two time points: prior to the initiation of the physical exercise program (baseline) and upon its completion (post-exercise). Additionally, a cohort of 20 participants, who underwent 18F-FDG PET/CT scans as part of a routine general health examination, were included as a non-obese control group. The quantification of brain amygdala activity (AmygA) involved determining the maximum standardized uptake value (SUVmax) of the amygdala, normalized to the mean SUV of the temporal lobe. Results: Regular physical exercise demonstrated a notable reduction in AmygA levels, accompanied by improvements in body adiposity and systemic inflammation. AmygA exhibited its highest values at baseline, followed by intermediate levels post-exercise, and the lowest levels in the non-obese control group (0.76 ± 0.17, 0.61 ± 0.1, 0.52 ± 0.09, p < 0.001). Additionally, exercise effectively nullified the correlation between AmygA and systemic inflammation. Conclusions: Regular physical exercise mitigated the metabolic activity of the amygdala associated with stress and disrupted its correlation with systemic inflammation in women with obesity. This investigation may elucidate the presumed mechanism by which exercise exerts a health-promoting impact on cardiovascular disease, specifically through the modulation of stress neurobiology.