Concentration of fasting C-Peptide and 1-h-postprandial C-Peptide in patients with type 2 diabetes were = 1, 07 ± 0, 76 và = 3, 29 ± 2, 18, significally lower than those of people without diabetes: = 1, 48 ± 0, 71 và = 5, 36 ± 1, 65 respectively (p=0, 003 and p=0, 000).