title: Differential patterns of insulin secretion and sensitivity in patients with type 2 diabetes mellitus and nonalcoholic fatty liver disease versus patients with type 2 diabetes mellitus alone.
abstract: BACKGROUND
  Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) often coexist and have adverse outcomes. The aim of our study was to elucidate metabolic abnormalities in patients with DM-NAFLD versus those with T2DM alone.
  
  
  METHODS
  Patients were divided into two groups: 26 T2DM patients with NAFLD and 26 gender-, age-, and body mass index-matched patients with T2DM alone. Patients took a 75-g oral glucose tolerance test (OGTT), which measured serum insulin and C-peptide (C-p) levels at baseline (0 min), 30 min, 60 min, and 120 min after glucose challenge.
  
  
  RESULTS
  Patients with DM-NAFLD or T2DM alone had similar blood glucose levels. β-cell hypersecretion was more obvious in patients with DM-NAFLD. In addition, fasting, early-phase, and late-phase C-peptide levels were significantly increased in patients with DM-NAFLD (ΔC-p 0-30 min, P < 0.05; Area Under the Curve (AUC) C-p/PG 30-120 min ratio, P < 0.01; and AUC C-p 30-120 min, P < 0.01). Hepatic and extrahepatic insulin resistance during the OGTT did not differ significantly between groups. Hepatic insulin sensitivity independently contributed to the early phase (0-30 min) of the OGTT in patients with T2DM and NAFLD, whereas a significant deficit in late insulin secretion independently contributed to the 30-120 min glucose status in patients with T2DM only.
  
  
  CONCLUSIONS
  In patients with similar levels of insulin resistance and hyperglycemia, DM-NAFLD was associated with higher serum insulin levels than T2DM alone. Hyperinsulinemia is caused mainly by β-cell hypersecretion. The present study demonstrates pathophysiological differences in mechanisms of insulin resistance in patients with DM-NAFLD versus T2DM alone.
authors.forename: Shang-Yu
authors.initials: SY
authors.lastname: Chai
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Pan
authors.forename: Ke-Xiu
authors.initials: KX
authors.lastname: Song
authors.forename: Yue-Ye
authors.initials: YY
authors.lastname: Huang
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Cheng
authors.affiliation: Department of Endocrinology, Shanghai 10th People's Hospital, Tongji University, Shanghai, China. qushencn@hotmail.com.
authors.forename: Shen
authors.initials: S
authors.lastname: Qu
mesh_terms: D001786:Blood Glucose; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005234:Fatty Liver / Q000097:blood*; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin