A detailed analysis of body composition in relation to cardiopulmonary fitness

<bold>Background:</bold> The results from a cardiopulmonary exercise test (CPET) are potentially affected by body composition. <bold>Aim:</bold> To assess the relationship between a detailed body composition analysis and indices obtained from CPET. <bold>Methods:</bold> A total of 233 participants (112 women), all aged 50, underwent both CPET and a whole-body MRI scan in which the body was divided into >1 million voxels. Voxel-wise statistical analysis was carried out by a method denoted Imiomics and related tissue volume to the following CPET indices: peak oxygen consumption (V̇O2peak), V̇O2peak scaled by body weight (V̇O2kg), work efficiency (ΔV̇O2/ΔWR) and ventilatory efficiency (V̇E/V̇CO2-slope). <bold>Results:</bold> V̇O2peak showed the highest positive correlation with volume of skeletal muscles. V̇O2kg had a negative correlation with tissue volume in subcutaneous fat, particularly gluteal fat. Some associations appeared to differ between sexes: ΔV̇O2/ΔWR correlated positively with tissue volume of subcutaneous fat in females. V̇E/V̇CO2-slope showed a positive relationship with tissue volume of visceral fat in females and V̇O2peak related to lung volumes in males (Figure 1). <bold>Conclusions:</bold> The Imiomics technique provided a detailed view of how CPET indices were related to body composition, increasing our understanding of which CPET indices are related to tissue volume of different body structures.