Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease that affects the liver and a variety of extra-hepatic organ systems. This study aimed to investigate the relationship between hepatic steatosis and glucose metabolism in liver and extra-hepatic tissues and organs. The whole body 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) images of 191 asymptomatic tumor screening patients were retrospectively analyzed. Patients with the ratio of spleen/liver CT densities > 1.1 were defined to have NAFLD, and their clinical symptoms, laboratory markers, FDG uptake in a variety of tissues and organs including heart, mediastinal blood pool, liver, spleen, pancreas, and skeletal muscle, as well as abdominal adipose tissue volumes including visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume were compared with those of the non-NAFLD patients and used to analyze the independent correlation factors of NAFLD. Among the 191 patients, 33 (17.3%) were NAFLD, and 158 (82.7%) were non-NAFLD. There was no significant correlation between the mean standardized uptake value (SUVmean) and CT density of liver as well as the ratio of spleen/liver CT densities. Hepatic steatosis, but not FDG intake, was more significant in NAFLD patients with abnormal liver function than those with normal liver function. Compared with the non-NAFLD patients, NAFLD patients had significantly reduced myocardial glucose metabolism, but significantly increased mediastinal blood pool, spleen SUVmean and abdominal adipose tissue volumes (including VAT and SAT volumes) (P < 0.05). Multivariate regression analysis showed that elevated serum ALT, increased abdominal VAT volume, and decreased myocardial FDG uptake were independent correlation factors for NAFLD. Further studies showed that hepatic steatosis and myocardial FDG uptake were mildly linearly correlated (r = 0.366 with hepatic CT density and − 0.236 with the ratio of spleen/liver CT densities, P < 0.05). NAFLD is a systemic disease that can lead to the change of glucose metabolism in some extra-hepatic tissues and organs, especially the myocardium.

中文翻译：

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肝脂肪变性与肝酶异常、内脏肥胖、18F-FDG PET/CT 测量的心肌葡萄糖摄取改变有关。


非酒精性脂肪肝（NAFLD）是一种影响肝脏和多种肝外器官系统的多系统疾病。本研究旨在探讨肝脏脂肪变性与肝脏及肝外组织器官糖代谢的关系。回顾性分析191例无症状肿瘤筛查患者的全身18F-氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）/计算机断层扫描（CT）图像。脾脏/肝脏CT密度比值> 1.1的患者被定义为NAFLD，其临床症状、实验室标志物、心脏、纵隔血池、肝脏、脾脏、胰腺等多种组织器官的FDG摄取情况将骨骼肌、腹部脂肪组织体积（包括内脏脂肪组织（VAT）体积和皮下脂肪组织（SAT）体积）与非NAFLD患者进行比较，并用于分析NAFLD的独立相关因素。在 191 名患者中，33 名（17.3%）为 NAFLD，158 名（82.7%）为非 NAFLD。平均标准化摄取值（SUVmean）与肝脏CT密度以及脾/肝脏CT密度比值之间无显着相关性。在肝功能异常的 NAFLD 患者中，与肝功能正常的患者相比，肝脏脂肪变性更显着，但 FDG 摄入量则不然。与非NAFLD患者相比，NAFLD患者心肌糖代谢显着降低，但纵隔血池、脾脏SUVmean和腹部脂肪组织体积（包括VAT和SAT体积）显着增加（P<<0.05）。 多因素回归分析显示，血清ALT升高、腹部VAT体积增加、心肌FDG摄取减少是NAFLD的独立相关因素。进一步的研究表明，肝脏脂肪变性和心肌 FDG 摄取呈轻度线性相关（肝脏 CT 密度 r = 0.366，脾/肝脏 CT 密度比 r = 0.236，P < 0.05）。 NAFLD是一种可导致肝外某些组织器官尤其是心肌糖代谢改变的全身性疾病。