Visceral adiposity: A major mediator of the relationship between epicardial adiposity and cardiorespiratory fitness in adults.

Background and aims: Epicardial adiposity has been positively associated with visceral adipose tissue (VAT). Few studies have examined the association between cardiorespiratory fitness (CRF) and epicardial adiposity. Furthermore, whether this relationship was independent of VAT remains unexplored. Our purpose was to investigate the contribution of VAT in the relationships between CRF, physical activity (PA) and epicardial adipose tissue (EAT) in asymptomatic women and men.

Methods and results: We examined the associations between EAT and VAT measured by magnetic resonance imaging, CRF measured by cardiopulmonary exercise testing, and PA assessed using pedometers and a 3-day PA journal in 239 apparently healthy adults (43 % women). Participants were compared according to EAT tertiles and CRF level in both sexes. Participants with the highest EAT level presented more VAT (p < 0.001), lower CRF (p < 0.01), and a more deteriorated cardiometabolic health score (p < 0.01) than those with the lowest EAT level. CRF was negatively associated with EAT in both sexes (p < 0.01). No significant relationship was found with PA (p = NS). Stepwise multivariable regression analyses showed that VAT explained most of the variance in EAT in women and men. Mediation analyses confirmed that VAT was a mediator of the association between CRF and EAT in both sexes.

Conclusion: In women and men, VAT appears as a major mediator of the association between CRF and EAT thereby suggesting that managing VAT by improving CRF could help in the prevention of cardiometabolic disorders related to excess EAT.