Correlation of body composition metrics with bone mineral density and computed tomography-based trabecular attenuation

Purpose: To investigate the relationship of body composition metrics with bone mineral density (BMD) and trabecular attenuation in a cohort of healthy individuals. Methods: We retrospectively analyzed data of consecutively evaluated individuals who underwent dual -energy Xray absorptiometry (DXA) and abdominopelvic computed tomography (CT) on the same day during routine medical check-ups between January 2021 and December 2021. Trabecular attenuation was measured at L1 level, while body composition metrics, including skeletal muscle index (SMI), skeletal muscle attenuation (SMA), visceral fat index (VFI), and subcutaneous fat index (SFI), were measured at L3 level. The association of body composition metrics with BMD and trabecular attenuation was analyzed using partial correlation analysis. Results: A total of 634 patients (median age, 56 years; range 50-62 years; 392 men) were included. In men, the SMI and SMA were positively correlated with BMD and trabecular attenuation, both before (r, 0.157-0.344; p < 0.05) and after (r, 0.103-0.246; p < 0.05) adjusting for age and body mass index. The VFI showed negative correlations with trabecular attenuation in both men (r, -0.170; p = 0.001) and women (r, -0.394; p < 0.001), which remained significant after adjusting for age and body mass index (r, -0.181 to -0.122; p < 0.05). Conclusion: Low skeletal muscle mass and attenuation were significantly correlated with low BMD and trabecular attenuation in men. Visceral adiposity was associated with reduced BMD and trabecular attenuation in both men and women, demonstrating a stronger correlation with trabecular attenuation.