Bridging Dose of U-100 Glargine with First Dose of Insulin Degludec Improves Glycemia in the 48 Hours after Transition In Twice-Daily Glargine Users

Background: Degludec (D), a once-daily basal insulin, takes 2-3 days to achieve steady state. When transitioning from insulin glargine (G) to D, 1:1 conversion is recommended. We studied the off-label effects of a bridging dose of G with the first dose of D in type 1 diabetes (T1D) patients using a continuous glucose monitor (CGM) 48 hours before and after the transition. Methods: Patients with T1D on a stable G regimen and A1C <9% were randomized (double-blind) to a dose of placebo or G with first dose of D. Patients transitioned to D at 80% of total baseline G dose, based on result of SWITCH 1 clinical trial of transition to D. Bridging dose of G was 50% of total daily G dose for patients on once daily (QD) regimen at baseline and 50% of evening G dose in those on twice daily (BID) G and was taken with only the first dose of D. All participants wore a study CGM (Dexcom G6) and were instructed to manage their diabetes as usual except for not administering correctional doses of insulin unless glucose was greater than 250 mg/dL in the 48 hours before and after first dose of D. Results: Forty participants were randomized and 37 completed the study. The study population was 65% male with mean age of 47 years, 22 years duration of T1D, BMI 26 kg/m2, A1C of 6.8% and total daily insulin dose of 0.7 units/kg body weight. Nineteen patients (12 QD, 7 BID) received a bridging dose of G with their first dose of D; 18 patients (12 QD, 6 BID) received placebo. Among the BID users, patients bridged with G had a mean 9% increase in time in range (70-180 mg/dL) on CGM, while placebo patients had a mean 12% decrease (p=0.003). Time above range (180-250 mg/dL) also showed a mean 11.4% decrease in the BID users bridged with G, contrasted with an 11.5% increase in BID users on placebo (p=0.002). There were no significant differences in time below ranges (<70 mg/dL, <54 mg/dL). Conclusions: Well-controlled twice-daily G users transitioning to D may benefit from a 50% bridging dose of evening G with first dose of D. Disclosure A.Thirumalai: Research Support; Novo Nordisk, Fractyl Health, Inc. J.H.Chao: None. T.Kaleru: None. X.Dong: None. P.Mandava: None. D.Khakpour: None. I.B.Hirsch: Consultant; Abbott Diabetes, Lifecare, Inc., Hagar, Research Support; Beta Bionics, Inc., Insulet Corporation, Dexcom, Inc. Funding Novo Nordisk (ISS001250)