Correlation between intrahepatic triglyceride content quantified by proton magnetic resonance spectroscopy and glucose metabolism / 中华内科杂志

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.

Characteristics of insulin sensitivity and insulin secretion in different types of impaired glucose regulation / 中华内分泌代谢杂志

Impaired glucose regulation includes three types, isolated-impaired fasting glucose, isolated-impaired glucose tolerance and combined glucose intolerance.The epidemiologic studies and pathogenetic studies indicate that each type has different characteristics of insulin secretion and insulin sensitivity.The distinct metabolic features conduce to different early interventions in order to prevent or delay their progress to type 2 diabetes.