[Correlation between intrahepatic triglyceride content quantified by proton magnetic resonance spectroscopy and glucose metabolism].

Objective: To investigate the correlation between intrahepatic triglyceride content (IHTC) and glucose metabolism in patients with non-alcoholic fatty liver disease (NAFLD) diagnosed by proton magnetic resonance spectroscopy (1H-MRS). Methods: A total of 239 subjects without diabetes mellitus were previously enrolled and underwent 1H-MRS scans. Anthropometric indexes including height, weight, waist and blood pressure, and laboratory findings as plasma glucose (PG), insulin (INS), C-peptide (CP), liver enzymes [alanine aminotransferase (ALT), aspartate transaminase (AST), γ-glutamyl transpeptidase (GGT)] and lipid profiles were collected. According to IHTC levels, participants were divided into three groups: the non-NAFLD group (IHTC<5.56%), the mild NAFLD group (IHTC 5.56%-<33%), and the moderate and severe NAFLD group (IHTC ≥ 33%). The clinical characteristics of each group were analyzed, and the correlation between IHTC and glucose metabolism were assessed. Results: Compared with those in the non-NAFLD group, male proportion, waist, 120 min postprandial PG (PG120), CP, liver enzymes and total cholesterol (TC) levels were greater in the NAFLD group, whereas insulin sensitivity index-Cederholm (ISI-Cederholm) and high density lipoprotein cholesterol (HDL-C) levels were lower in the NAFLD groups. Subjects in the moderate and severe NAFLD group had higher levels of 120 min postprandial INS (INS120) and Stumvoll indexes, and lower ISI-Cederholm than those in the mild NAFLD group [80.37 (57.68, 112.70) mU/L vs.110.50(71.78, 172.80)mU/L, 1453(1178, 1798)vs.1737(1325, 2380), 358(297, 446) vs.441(318, 594), 2.27(2.01, 2.53) vs.2.06(1.81, 2.39), respectively, all P<0.05]. Correlation analyses showed that IHTC was significantly positively correlated with waist hip ratio (WHR), PG120, INS120, HOMA insulin resistance (HOMA-IR), Stumvoll 1st-insulin secretion, Stumvoll 2nd-insulin secretion, ALT, AST, GGT and TC (r=0.197, 0.274, 0.334, 0.162, 0.199, 0.211, 0.406, 0.361, 0.215, and 0.196, respectively, all P<0.05), and negatively correlated with ISI-Cederholm and HDL-C (r=-0.334, and-0.237, respectively, all P<0.05). Furthermore, a multiple linear stepwise regression analysis indicated that ISI-Cederholm (Standardized β =-0.298, P<0.001) and Stumvoll 1st insulin secretion (Standardized β = 0.164, P = 0.024) were independent factors of IHTC. Conclusions: Peripheral insulin resistance occurs in the early stage of NAFLD and becomes worse with the progression of the disease. IHTC was independently associated with insulin sensitivity and first-phase insulin secretion.目的： 探讨1H-核磁共振波谱学（1H-MRS）诊断的非酒精性脂肪性肝病（NAFLD）患者肝内脂肪含量（IHTC）与糖代谢的相关性。 方法： 选取前期研究招募的239例受试者，进行1H-MRS检测且均无糖尿病，获取其身高、体重、腰围、血压、血糖、胰岛素、C肽、丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、γ-谷氨酰转肽酶（GGT）、血脂谱等资料。根据1H-MRS测定的IHTC将受试者分为3组：无NAFLD组（IHTC<5.56%）、轻度NAFLD组（IHTC 5.56%~<33%）、中重度NAFLD组（IHTC ≥ 33%），分析各组临床特征，并探讨IHTC与糖代谢的相关性。 结果： NAFLD组中男性比例、腰围、糖负荷后120 min 血糖（PG120）、C肽、ALT、AST、总胆固醇（TC）水平高于无NAFLD组，而胰岛素敏感指数（ISI-Cederholm）、高密度脂蛋白胆固醇（HDL-C）水平低于无NAFLD组（P值均<0.05）。相比于轻度NAFLD组，中重度NAFLD组的糖负荷后120 min胰岛素（INS120）［80.37（57.68，112.70）mU/L比110.50（71.78，172.80）mU/L］、一相及二相胰岛素分泌指数（Stumvoll 1st、Stumvoll 2nd指数）［1 453（1 178，1 798）比1 737（1 325，2 380）、358（297，446）比441（318，594）］更高，而ISI-Cederholm较低［2.27（2.01，2.53）比2.06（1.81，2.39）］，P值均<0.05。关联分析结果显示，IHTC与腰臀围比、PG120、INS120、稳态模型法评估的胰岛素抵抗指数（HOMA-IR）、Stumvoll 1st及Stumvoll 2nd指数、ALT、AST、GGT、TC等显著正相关（r值分别为0.197、0.274、0.334、0.162、0.199、0.211、0.406、0.361、0.215、0.196，P值均<0.05），与ISI-Cederholm、HDL-C负相关（r值分别为-0.334、-0.237，P值均<0.05）。多元线性逐步回归分析进一步证实ISI-Cederholm（Standardized β=-0.298，P<0.001）和Stumvoll 1st（Standardized β = 0.164，P = 0.024）是IHTC的独立影响因素。 结论： NAFLD早期以外周胰岛素抵抗为主，随病程进展加重，并且出现一相、二相胰岛素分泌增加。IHTC与胰岛素敏感性及一相胰岛素分泌独立相关。.