Effects of Twice-Daily Injections of Premixed Insulin Analog on Glycemic Control in Type 2 Diabetic Patients

PURPOSE Premixed insulin is effective to improve glycemic control; however, clinicians may be less likely to know which premixed insulin is appropriate for which patients. This study aimed to evaluate the effects of twice-daily injections of premixed insulin lispro on glycemic control in type 2 diabetic patients. MATERIALS AND METHODS Forty type 2 diabetic patients, who had been treated with twice-daily injections of human protamine mixture 30/70 insulin for at least 12 months, were divided into two groups; one group whose blood glucose 2 hours after breakfast was greater than 200 mg/dL, was switched to lispro mix50, and the other group whose blood glucose 2 hours after breakfast < 200 was switched to lispro mix25. RESULTS Glycated haemoglobin (HbA1c) significantly improved in the Mix50 group from 8.3% to 7.5% (at 12 weeks; p < 0.05), and to 7.5% (at 24 weeks; p < 0.05). On the other hand, HbA1c levels in the Mix25 group were slightly decreased from 8.1% to 7.7% at 12 weeks (p < 0.05), and to 7.9% at 24 weeks (not significant). Both postprandial plasma glucose and fasting plasma glucose levels were significantly improved in the Mix50 group, but not in the Mix25 group. Overall, 95% of subjects preferred premixed lispro insulin from human insulin in the viewpoint of the timing of insulin injection by questionnaire analysis. CONCLUSION Switching from human protamine mixture 30/70 insulin to lispro mix50 twice-daily injection therapy in patients with high postprandial plasma glucose could improve their glycemic control and quality of life.