Background and objectives: Excess visceral adiposity (VAT) and liver fat (LF) content increase cardiometabolic risk (CMR). This study aimed to assess the contribution of cardiorespiratory fitness (CRF) to the association between VAT, LF and markers of CMR in women and men.
Methods: Participants included 134 women and 177 men without evidence of cardiovascular disease from the Visceral obesity/ectopic fat and non-invasive markers of atherosclerosis: a cardiometabolic-cardiovascular imaging (CMCV) study. An oral glucose tolerance test, a maximal treadmill exercise test and a magnetic resonance imaging and spectroscopy examination were performed. Age-adjusted ANOVAs and multiple regression analyses were performed to evaluate the contribution of CRF on VAT, LF and CMR factors and to quantify the respective contributions of CRF, VAT and LF to the variation in CMR factors.
Results: Men in the lowest CRF tertile had the highest VAT values (p<0.0001) and were characterized by higher LF content compared with men in the top tertile (p<0.0001). In women, only a trend for LF was observed between low and top CRF tertiles (p=0.07). Moreover, men in the lowest CRF tertile showed increased AUC insulin and glucose compared with those in the middle (p<0.01) and top CRF tertiles (p<0.005), while in women these differences were observed only between the lowest and the top CRF tertiles (p<0.005). Multiple regression analyses revealed that VAT contributed the most to the variance in plasma insulin (R2=0.30) and HOMA-IR (R2=0.37) in women and plasma glucose (R2=0.20), insulin (R2=0.32) and HOMA-IR (R2=0.38) in men. LF explained most of the variation in plasma glucose (R2=0.26) in women.
Conclusions: A low CRF is associated with higher VAT and LF translating into a deteriorated CMR profile. Identification of individuals with a low CRF should be promoted in order to identify individuals at higher CMR who would benefit substantially from preventive lifestyle interventions.