关键词: 肌营养不良, 心肌病, 心脏磁共振, 双能X线吸收法, 心外膜脂肪组织, 全身瘦体质量, 脂肪分数

Abstract:

Objective The aim of this study was to quantitatively evaluate the volume of epicardial adipose tissue （EAT） in patients with muscular dystrophy（MD）-associated cardiomyopathy using cardiac magnetic resonance （CMR） and to explore its correlation with the total body composition measured by dual-energy X-ray absorptiometry （DXA）. Methods Male children diagnosed with MD-associated cardiomyopathy， who simultaneously underwent 3.0 T CMR and whole-body DXA at Sun Yat-sen Memorial Hospital from January 2018 to December 2023， were retrospectively included in this study. Healthy male children matched for age and body mass index （BMI） served as controls. The EAT volume， anterior septal fat thickness， and left and right atrial septal fat thickness were calculated by manually delineating the pericardium on CMR short-axis cine sequences using dedicated post-processing software. DXA was used to measure fat mass （FM）， fat fraction （FF）， and lean body mass （LBM）. All the above parameters were divided by the square of height and normalized to obtain relevant indexes， namely the epicardial adipose tissue volume index （EATVI）， whole-body fat mass index （FMI）， FF， and whole-body lean body mass index （LBMI）. Pearson correlation analysis was employed to assess the correlation between EAT and DXA. Results A total of 55 children with MD-associated cardiomyopathy ［age （12.42 ± 2.65） years］ and 21 healthy controls ［age （12.67 ± 2.15） years］ were recruited. There was a statistically significant difference in the epicardial adipose tissue volume index between children with MD-associated cardiomyopathy and healthy controls ［（28.0 ± 3.3） mL/m2 vs. （19.2 ± 2.9） mL/m2， P < 0.05］. For the anteroventricular septal fat thickness index ［（2.75 ± 2.15） mm/m2 vs. （2.27 ± 2.24） mm/m2， P > 0.05］， the left atrioventricular septal fat thickness index ［（2.83 ± 2.20） mm/m2 vs. （2.78 ± 2.64） mm/m2， P > 0.05］， and the right atrioventricular septal fat thickness index ［（4.97 ± 2.59） mm/m2 vs. （4.42 ± 3.60） mm/m2， P > 0.05］， no significant differences were found. There were significant differences in the total body fat mass index ［（3.93 ± 2.49） kg/m2 vs. （2.73 ± 1.38） kg/m2， P < 0.05］， the percentage fat fraction ［（18 ± 8） vs. （16 ± 5）， P > 0.05］， and the total body lean mass index ［（14.59 ± 1.90） kg/m2 vs. （15.99 ± 1.83） kg/m2， P < 0.05］. Correlation analysis indicated that the epicardial adipose tissue volume index was positively correlated with the body fat mass index （r = 0.62， P < 0.05） and the body fat fraction （r = 0.47， P < 0.001） measured by DXA. The epicardial adipose tissue volume index was negatively correlated with the total lean body mass index （r = -0.61， P < 0.001）. Conclusions In patients diagnosed with myodystrophic cardiomyopathy， the volume of EAT quantified via CMR exhibits a strong correlation with the trunk and whole-body fat content measured by DXA. This implies that the accumulation of EAT might mirror a distinct visceral fat distribution pattern among patients with MD. Furthermore， the EAT volume was found to be correlated with muscle atrophy， which underscores a potential interplay between the impaired fat metabolism and muscle wasting in these patients.

Key words: muscular dystrophy, cardiomyopathy, cardiac magnetic resonance imaging, dual-energy X-ray absorptiometry, epicardial adipose tissue, whole body lean mass, fat fraction