Faster-acting insulin aspart versus insulin aspart for adults with type 1 diabetes treated with non-automated insulin pump and continuous glucose monitoring—A double-blind randomized controlled crossover trial

Objective

To evaluate the efficacy and safety of faster-acting insulin aspart (faster aspart) compared with insulin aspart in adults with type 1 diabetes (T1D) using a non-automated insulin pump and continuous glucose monitoring (CGM).

Methods

This double-blinded crossover study randomly assigned participants to start with either faster aspart or insulin aspart for 16 weeks, followed by a 3-week washout period, then switching to the alternate therapy for another 16 weeks. Insulin pump settings were adjusted every 3 weeks. The primary outcome was time in range (TIR: 3.9–10.0 mmol/L). Secondary outcomes included other CGM metrics and HbA1c.

Results

Forty adults (20 males) with a median age of 54 years, T1D duration of 27 years, and HbA1c of 59 mmol/mol (7.5%) were included. At the study end, TIR was (mean ± SD) 60.6 ± 12.1% for insulin aspart and 62.5 ± 12.3% for faster aspart, p = 0.24 (primary endpoint). The baseline-adjusted estimated treatment difference (ETD) for TIR was 6.0% (95%CI: 2.2;9.9), p = 0.002; time above range (>10.0 mmol/L) was −5.7% (−9.8; −1.6), p = 0.007; and time below range (<3.9 mmol/L) was −0.4% (−1.1;0.4), p = 0.30—all in favour of faster aspart. Faster aspart significantly improved the coefficient of variation (34.0 ± 3.7% vs. 35.9 ± 4.9%, p = 0.02) and the HbA1c levels (ETD −1.9 (−3.7; −0.2) mmol/mol or − 0.18% (−0.34;-0.02), p = 0.03). No significant differences were observed in severe adverse events, including severe hypoglycaemia and diabetic ketoacidosis. Faster aspart had more injection site reactions than insulin aspart (p = 0.03).

Conclusion

Faster aspart improved baseline-adjusted TIR, TAR, CV and HbA1c after 16 weeks with frequent insulin pump adjustments but had a higher incidence of injection site reactions.