Objective: To compare blood glucose control when using biphasic insulin aspart (BIAsp) three times a day (using 70/30 high-mix before breakfast and lunch), with biphasic human insulin (BHI, 30/70) twice daily in adults with type 2 diabetes already treated with insulin.
Research design and methods: In a 60-day, open-label, crossover study, people with insulin-treated type 2 diabetes [n = 38, baseline haemoglobin A1c 8.3 +/- 0.9 (s.d.) %] were randomized to BIAsp three times a day before meals, as BIAsp 70 (70% insulin aspart and 30% protamine-complexed insulin aspart) before breakfast and lunch and BIAsp 30 (30/70 free and protamine-complexed insulin aspart) before dinner, or to human premix insulin (BHI) 30/70 twice a day before meals. A 24-h in-patient plasma glucose profile was performed at the end of each 30-day treatment period. The total daily insulin dose of BIAsp regimen was 110% of BHI and the doses were not changed during the study.
Results: There was no difference between BIAsp and BHI in geometric weighted average serum glucose over 24 h [7.3 vs. 7.7 mmol/l, BIAsp/BHI ratio 0.95 (95% CI 0.88-1.02), not significant (NS)], but daytime geometric weighted average glucose concentration was significantly lower with the BIAsp regimen than with BHI [8.3 vs. 9.2 mmol/l, BIAsp/BHI ratio 0.90 (0.84-0.98), p = 0.014]. The mealtime serum glucose excursion was also lower with BIAsp than with BHI with statistically significant differences at lunchtime [difference -4.9 (-7.0 to -2.7) mmol/l, p = 0.000); the difference in glucose excursions above 7.0 mmol/l was also significant [-5.8 (-8.3 to -3.2) mmol/l, p = 0.000). The proportion of participants experiencing confirmed hypoglycaemic episodes was similar between regimens (42 vs. 43%, NS).
Conclusions: An insulin regimen using high-mix BIAsp (BIAsp 70) before breakfast and lunch and BIAsp 30 before dinner can achieve lower blood glucose levels during the day through reduced mealtime glucose excursions in particular at lunchtime than a twice-daily premix regimen.