Wen Qun, Wang Jiaoyan, Yuan Jie, Gong Zhigang, Huang Yanwen, Zhan Songhua, Tan Guang, Liu Mengxiao, Tan Wenli
Department of Radiology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
MR Scientific Marketing, Diagnostic Imaging, Siemens Healthineers Ltd., Shanghai, China.
Quant Imaging Med Surg. 2025 Jun 6;15(6):5463-5473. doi: 10.21037/qims-24-1696. Epub 2025 May 26.
Metabolic dysfunction-associated fatty liver disease (MAFLD)-a major global health concern-is known to influence skeletal muscle. Therefore, in this study, we investigated whether the changes fat in skeletal muscle are associated with the degree of fatty liver in patients with MAFLD.
We evaluated 398 patients who underwent abdominal magnetic resonance imaging (MRI) between January 2020 and August 2023 in a tertiary university hospital. Using MRI proton density fat fraction (PDFF), two radiologists manually measured the hepatic fat fraction (HFF), psoas major fat fraction (PMFF), paraspinal muscle fat fraction (PAMFF), and subcutaneous adipose tissue thickness (SATT). The severity of hepatic fatty deposition was classified as follows: G0, HFF <5%; G1, 5%≤ HFF <10%; G2, 10%≤ HFF <25%; and G3, HFF ≥25%).
PMFF and PAMFF increased in a stepwise manner as the severity of hepatic steatosis increased. There were no significant differences in PMFF or PAMFF between the G2 and G3 groups (P=0.058), while PMFF and PAMFF differed significantly between the other groups (P<0.05). The Pearson analysis showed that HFF was positively correlated with PMFF (r=0.475; P<0.001) and PAMFF (r=0.343; P<0.001). After adjustments were made for the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), and albumin (ALB), these correlations remained significant (PMFF: r=0.332, P<0.001; PAMFF: r=0.392, P<0.001). PMFF was positively correlated with age (r=0.155; P=0.002), ALT (r=0.169; P=0.003), AST (r=0.186; P=0.001), and blood glucose levels (r=0.177; P=0.003). PAMFF was positively correlated with age (r=0.107; P=0.033), ALT (r=0.118; P=0.040), AST (r=0.169; P=0.004), and blood glucose level (r=0.138; P=0.020) but negatively correlated with ALB level (r=-0.168; P=0.004). SATT was negatively correlated with age (r=-0.301; P=0.000), TG (r=-0.171; P=0.003), and ALB (r=-0.145; P=0.013). HFF was positively correlated with blood glucose level (r=0.144; P=0.015), and blood glucose level partly mediated the relationship between HFF and PAMFF (indirect effect =0.0046; 95 % CI: 0.0004-0.0130).
Skeletal muscle fat content is significantly associated with the severity of hepatic steatosis. Accurate and quantitative body composition measurement and degree of hepatic steatosis can be noninvasively performed using PDFF.
代谢功能障碍相关脂肪性肝病（MAFLD）——一个全球主要的健康问题——已知会影响骨骼肌。因此，在本研究中，我们调查了MAFLD患者骨骼肌中脂肪的变化是否与脂肪肝程度相关。
我们评估了2020年1月至2023年8月在一家三级大学医院接受腹部磁共振成像（MRI）检查的398例患者。两名放射科医生使用MRI质子密度脂肪分数（PDFF）手动测量了肝脏脂肪分数（HFF）、腰大肌脂肪分数（PMFF）、椎旁肌脂肪分数（PAMFF）和皮下脂肪组织厚度（SATT）。肝脏脂肪沉积的严重程度分类如下：G0，HFF<5%；G1，5%≤HFF<10%；G2，10%≤HFF<25%；G3，HFF≥25%）。
随着肝脏脂肪变性严重程度的增加，PMFF和PAMFF呈逐步增加。G2组和G3组之间的PMFF或PAMFF无显著差异（P=0.058），而其他组之间的PMFF和PAMFF差异显著（P<0.05）。Pearson分析显示，HFF与PMFF（r=0.475；P<0.001）和PAMFF（r=0.343；P<0.001）呈正相关。在对丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇（HDL-C）、甘油三酯（TG）和白蛋白（ALB）水平进行调整后，这些相关性仍然显著（PMFF：r=0.332，P<0.001；PAMFF：r=0.392，P<0.001）。PMFF与年龄（r=0.155；P=0.002）、ALT（r=0.169；P=0.003）、AST（r=0.186；P=0.001）和血糖水平（r=0.177；P=0.003）呈正相关。PAMFF与年龄（r=0.107；P=0.033）、ALT（r=0.118；P=0.040）、AST（r=0.169；P=0.004）和血糖水平（r=0.138；P=0.020）呈正相关，但与ALB水平呈负相关（r=-0.168；P=0.004）。SATT与年龄（r=-0.301；P=0.000）、TG（r=-0.171；P=0.003）和ALB（r=-0.145；P=0.013）呈负相关。HFF与血糖水平呈正相关（r=0.144；P=0.015），血糖水平部分介导了HFF与PAMFF之间的关系（间接效应=0.0046；95%CI：0.0004-0.0130）。
骨骼肌脂肪含量与肝脏脂肪变性的严重程度显著相关。使用PDFF可以无创地进行准确的定量身体成分测量和肝脏脂肪变性程度评估。
