Aims: To compare the efficacy of insulin aspart, a rapid-acting insulin analogue, with that of unmodified human insulin on long-term blood glucose control in Type 1 diabetes mellitus.
Methods: Prospective, multi-centre, randomized, open-labelled, parallel-group trial lasting 6 months in 88 centres in eight European countries and including 1,070 adult subjects with Type 1 diabetes. Study patients were randomized 2:1 to insulin aspart or unmodified human insulin before main meals, with NPH-insulin as basal insulin. Main outcome measures were blood glucose control as assessed by HbA1c, eight-point self-monitored blood glucose profiles, insulin dose, quality of life, hypoglycaemia, and adverse events.
Results: After 6 months, insulin aspart was superior to human insulin with respect to HbA1c with a baseline-adjusted difference in HbA1c of 0.12 (95% confidence interval 0.03-0.22) %Hb, P < 0.02. Eight-point blood glucose profiles showed lower post-prandial glucose levels (mean baseline-adjusted -0.6 to -1.2 mmol/l, P < 0.01) after all main meals, but higher pre-prandial glucose levels before breakfast and dinner (0.7-0.8 mmol/l, P < 0.01) with insulin aspart. Satisfaction with treatment was significantly better in patients treated with insulin aspart (WHO Diabetes Treatment Satisfaction Questionnaire (DTSQ) baseline-adjusted difference 2.3 (1.2-3.3) points, P < 0.001). The relative risk of experiencing a major hypoglycaemic episode with insulin aspart compared to human insulin was 0.83 (0.59-1.18, NS). Major night hypoglycaemic events requiring parenteral treatment were less with insulin aspart (1.3 vs. 3.4% of patients, P < 0.05), as were late post-prandial (4-6 h) events (1.8 vs. 5.0% of patients, P < 0.005).
Conclusions: These results show small but useful advantage for the rapid-acting insulin analogue insulin aspart as a tool to improve long-term blood glucose control, hypoglycaemia, and quality of life, in people with Type 1 diabetes mellitus.