The Impact of Myosteatosis on Cardiac Function in a Healthy Population: Insights from Abdominal CT Imaging

BackgroundEctopic fat deposition in skeletal muscle, termed myosteatosis, is a key factor in insulin resistance and contributes to various metabolic disturbances. This study evaluated the association between myosteatosis, assessed via abdominal computed tomography, and cardiac function in an asymptomatic Korean population. MethodsThis cross-sectional study included 7,716 participants (4,902 [63.5%] men and 2,814 [36.5%] women, mean age 53.2 {+/-} 8.0) who underwent routine health check-ups at Asan Medical Center (Seoul, Korea). Myosteatosis was evaluated by segmenting the total abdominal muscle area (TAMA) at the L3 vertebral level into normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA), and inter-/intra-muscular adipose tissue (IMAT). Patients were categorized into quartiles based on the NAMA/TAMA index, calculated by dividing the NAMA by TAMA and multiplying by 100. Cardiac function was assessed by transthoracic echocardiography. ResultsHigher NAMA/TAMA index levels were associated with decreased absolute values of the E/E ratio and increased E/A ratio in both men and women. Multiple linear regression analysis revealed a significant correlation between the NAMA/TAMA index and both the E/A and E/E ratios after adjusting for covariates. No significant correlation was found with left ventricular (LV) ejection fraction or LV mass index. ConclusionsThe degree of myosteatosis was significantly associated with diastolic function in an asymptomatic population, while systolic function remained unaffected.