Associations of thoracic muscle area factor and visceral adiposity with cardiac function in patients with overweight or obesity.

BACKGROUND AND AIMS: We investigated the independent and interactive associations of thoracic axial skeletal muscle mass (TASM) factor and visceral fat with cardiac function.

METHODS AND

RESULTS

This study evaluated 154 overweight/obese patients who underwent cardiac magnetic resonance. TASM factor and visceral fat thickness were quantified. Associations with left ventricular ejection fraction (EF), global circumferential strain (GCS), and N-terminal B-type natriuretic peptide were assessed using correlation, hierarchical regression, simple slope, subgroup, and exploratory indirect association analyses. TASM factor correlated positively with EF (r = 0.584) and |GCS| (r = 0.703); visceral fat showed negative correlations (r_EF = -0.559, r_|GCS| = -0.388; all p < 0.001). Significant muscle-fat interactions were found for EF (β = -2.985, p = 0.023) and |GCS| (β = 1.762, p = 0.043). Simple slope analysis showed the beneficial muscle-EF association was stronger at lower visceral fat levels (β = 20.137 vs. β = 10.789). Subgroup analysis suggested high muscle and low fat tended to show more favorable cardiac function, whereas low muscle and high fat showed poorer outcomes. In exploratory indirect association analysis, TASM factor and visceral fat exhibited opposing indirect patterns in the body mass index-EF relationship (via muscle: 36.42%; via visceral fat: -30.07%).

CONCLUSION

TASM factor and visceral fat exhibit contrasting independent and interactive associations with cardiac function, and visceral adiposity is associated with an attenuation of the positive correlation between TASM factor and cardiac function. These findings suggest a role for body composition profiling in cardiovascular risk stratification.