A high-mix biphasic insulin aspart (BIAsp) insulin three-times-daily regimen achieves lower blood glucose levels during the day for Type 2 diabetics than a twice-daily premix human insulin regimen, researchers report.

Meal-related glucose excursions can be a problem with both twice-daily injections of premixed (biphasic) human insulin and premixed insulin analogues.

To investigate approaches to improving postmeal blood glucose that do not involve moving to a four injection (mealtime plus basal) regimen, Umesh Dashora and colleagues (Newcastle University, Newcastle, UK) compared BIAsp three times a day (using 70/30 rapid acting: protamine complexed, high-mix) with biphasic human insulin (30/70) twice daily in adults with Type 2 diabetes already treated with insulin.

In the 60-day crossover study, BIAsp three times daily was administered as BIAsp 70/30 before breakfast and lunch, and BIAsp 30 before dinner to ensure sufficient basal insulin overnight. The human premix insulin was given before breakfast and dinner.

The total daily insulin dose of the BIAsp regimen was 110% of the human premix regimen and the doses were not changed during the study.

Blood glucose levels and insulin doses were reviewed every 15 days. In between, participants performed daily self-monitoring of blood glucose before meals. A 24-hour in-patient plasma glucose assessment was performed at the end of each 30-day treatment period.

The results, reported in the journal Diabetes, Obesity and Metabolism, show that the average 24-hour plasma glucose did not differ statistically between BIAsp and human premix regimens (7.3 mmol/l vs 7.7 mmol/l, respectively), but daytime average glucose concentration was 0.9 mmol/l lower with BIAsp (8.3 mmol/l vs 9.2 mmol/l, respectively).

BIAsp was also associated with lower mealtime serum glucose excursions than human premix and significantly less glucose excursions above 7.0 mmol/l.

The authors suggest that these observations might be clinically relevant, particularly as they relate to a reduction in the peaks of glucose after meals, which are the highest and most harmful glucose levels of the day.

The proportion of participants experiencing confirmed hypoglycemic episodes was similar between regimens (42% vs 43%), but the authors note that the study lacks power to provide reliable estimates of hypoglycemia.

“This study suggests that a thrice-daily analogue-based BIAsp regimen using high ratio free: protamine-complexed insulin with about 10% daytime insulin dose increase can trim postlunch glucose excursions when compared with a conventional human premix regimen,” conclude the authors.

“However, the utility of and safety of the regimen would need longer study to define which groups of people with Type 2 diabetes might benefit,” they add.

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