Background: Faster aspart is insulin aspart (IAsp) in a new formulation, which in continuous subcutaneous insulin infusion (CSII) in subjects with type 1 diabetes has shown a faster onset and offset of glucose-lowering effect than IAsp.
Methods: This double-blind, randomized, crossover active-controlled trial compared 2-h postprandial plasma glucose (PPG) response, following 2 weeks of CSII with faster aspart or IAsp. Primary endpoint: mean change in PPG 2 h after a standardized meal test (ΔPGav,0-2h). Subjects (n = 43) had masked continuous glucose monitoring (CGM) throughout.
Results: Faster aspart provided a statistically significantly greater glucose-lowering effect following the meal versus IAsp: ΔPGav,0-2h: 3.03 mmol/L versus 4.02 mmol/L (54.68 mg/dL vs. 72.52 mg/dL); estimated treatment difference (ETD) [95% CI]: -0.99 mmol/L [-1.95; -0.03] (-17.84 mg/dL [-35.21; -0.46]; P = 0.044). One hour postmeal, PG levels were -1.64 mmol/L (-29.47 mg/dL) lower with faster aspart versus IAsp (P = 0.006). Interstitial glucose (IG) profiles supported these findings; the largest differences were observed at breakfast: 9.08 versus 9.56 mmol/L (163.57 vs. 172.19 mg/dL; ETD [95% CI]: -0.48 mmol/L [-0.97; 0.01]; -8.62 mg/dL [-17.49; 0.24]; P = 0.057). Duration of low IG levels (≤3.9 mmol/L [70 mg/dL] per 24 h) was statistically significantly shorter for faster aspart versus IAsp (2.03 h vs. 2.45 h; ETD [95% CI]: -0.42 [-0.72; -0.11]; P = 0.008). No unexpected safety findings were observed.
Conclusions: CSII delivery of faster aspart had a greater glucose-lowering effect than IAsp after a meal test. CGM results recorded throughout all meals supported this finding, with less time spent with low IG levels.
Keywords: Continuous glucose monitoring; Continuous subcutaneous insulin infusion; Insulin pump; Meal test; Postprandial plasma glucose; Type 1 diabetes.