Metabolic factors mediate the association between intermuscular adipose tissue and subclinical atherosclerosis

BACKGROUND Several studies have linked skeletal muscle mass with cardiovascular disease. The clinical significance of myosteatosis in subclinical atherosclerosis has not been well investigated. OBJECTIVE The aim of this study was to explore the relationship between intermuscular adipose tissue (IMAT) and subclinical atherosclerosis, and to determine the extent to which this association is mediated by metabolic factors. METHODS We retrospectively enrolled 1993 participants who underwent abdominal computed tomography (CT) scans in our health promotion center between April 2021 and October 2023. IMAT was assessed by abdominal quantitative CT scans. Carotid atherosclerosis (CAS) and brachial ankle pulse wave velocity (baPWV) were selected as subclinical atherosclerosis markers. RESULTS Compared with participants without CAS, those with CAS showed significantly increased IMAT% (7.40 ± 3.37% vs 6.76 ± 2.66%, P < .01). According to a multiple logistic regression model, IMAT% was significantly correlated with CAS (odds ratio OR = 1.18, 95% CI 1.13-1.23, P < .001) and baPWV (OR = 1.25, 95% CI 1.13-1.37, P < .001). However, when the model was adjusted for age, the associations of IMAT% with CAS and baPWV were no longer significant. In stratified analyses, there was a significant relationship between IMAT% and subclinical atherosclerosis in participants <60 years old, but not in those ≥60 years old. Mediation analysis showed that body mass index (BMI), blood pressure, fasting plasma glucose, and hemoglobin A1c partially accounted for a statistical portion of the association between IMAT% and subclinical atherosclerosis. CONCLUSION IMAT% is positively correlated with subclinical atherosclerosis. Furthermore, this association may be partially mediated by BMI, blood pressure, and blood glucose levels.