title: Relationship between β-cell function, metabolic control, and microvascular complications in type 2 diabetes mellitus.
abstract: BACKGROUND
  This study investigated the relationship among β-cell function, metabolic control, and diabetic microvascular complications in patients with type 2 diabetes mellitus (T2DM).
  
  
  METHODS
  In total, 885 patients with type 2 diabetes mellitus (DM) were recruited from January 2012 to January 2014 and grouped into three groups according to the area under the curve of C-peptide [AUC(C-pep)] during the 75-g oral glucose tolerance test. Logistic regression analyses were used to evaluate the association between C-peptide and microvascular complications.
  
  
  RESULTS
  The prevalence of diabetic microvascular complications decreased from the first to the third AUC(C-pep) tertile (P < 0.01 for all), whereas the rates of nonalcoholic fatty liver disease (NAFLD) was positively associated with AUC(C-pep) values. Patients with lower AUC(C-pep) tertile exhibited higher levels of glycosylated hemoglobin and high-density lipoprotein cholesterol and longer duration of DM; however, levels of triglycerides, fasting C-peptide, 2-h C-peptide, body mass index, and homeostasis model assessment of insulin resistance index were lower compared with the third tertile. Comparison among patients with a similar DM duration showed a higher level of AUC(C-pep) was inversely associated with prevalence of microvascular complications. The odds ratios for nephropathy, retinopathy, and neuropathy in the lowest versus the highest AUC(C-pep) tertile were 3.10 (95% confidence interval, 2.01-4.78), 2.83 (1.73-4.64), and 2.04 (1.37-3.04) after adjustment for confounding factors.
  
  
  CONCLUSIONS
  Higher AUC(C-pep) levels were associated with a decreased prevalence of microvascular complications and a good level of glycemic control, whereas higher endogenous insulin levels were linked to the components of metabolic syndrome and increased rates of NAFLD.
authors.affiliation: Department of Diabetic Neurology, Hospital of Metabolic Disease, Tianjin Medical University , Tianjin, China .
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.forename: Shaoxin
authors.initials: S
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Xie
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications*; D003925:Diabetic Angiopathies / Q000453:epidemiology / Q000209:etiology*; D005215:Fasting; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000502:physiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000209:etiology; D016017:Odds Ratio; D015995:Prevalence; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D006442:Glycated Hemoglobin; D014280:Triglycerides