Low muscle mass is related to cardiovascular risk factors. This study aimed to investigate whether relative low muscle mass is related to the diameter and tortuosity of the aorta.

We performed a cross-sectional study of 208 adults without known cardiovascular disease who underwent Computed Tomography (CT) enhanced scan between 2020 and 2021. Skeletal muscle index (SMI) was estimated. The morphology of the aorta was measured by diameter and tortuosity using CT. We assessed the relationship between SMI and diameter and tortuosity of the aorta using Spearman correlation analysis and univariate and multivariate-adjusted regression models.

Of all -individuals, 124 (59.6%) were male. The average age was 60.13 ± 16.33 years old. SMI was inversely associated with the diameter and tortuosity of the aorta (p < 0.05). Specifically, in a multivariable-adjusted model adjusting for potential confounders, a one-unit increase in the SMI was associated with a -13.56mm(95% confidence intervals (CI): −18.16 to −8.96, p < 0.001), −7.93 mm (95% CI: −10.85 to −5.02, p < 0.001), −8.01 mm (95% CI: −11.30 to −4.73, p < 0.001), −5.16 mm (95% CI: −7.57 to −2.75, p < 0.001) and −2.73 mm (95% CI: −5.18 to −0.27, p = 0.031) increase in L1-L5 diameter respectively, a −0.89 (95% CI: −1.14 to −0.64, p < 0.001) increase in the aorta tortuosity, a −0.48 (95% CI: −0.59 to −0.36, p < 0.001) increase in the descending thoracic aorta tortuosity, and a −0.44 (95% CI: −0.52 to −0.35, p < 0.001) increase in the abdominal aorta tortuosity.

Relative muscle mass was negatively associated with the diameter and tortuosity of the aorta, suggesting muscle mass maintenance may play a role in preventing aortic morphological changes.