INS and diabetes mellitus: As shown in Table 1, there were no significant differences in age, gender, BMI, HbA1c level, duration of diabetes, fasting C-peptide (C-p 0′) level, 2 h postprandial C-p (C-p 120′) level, the number of patients with decreasing C-p 0′ level or decreasing C-p 120′ level, the ratio of human insulin over insulin analogues, and the ratio of oral antidiabetes drugs among the three groups.