107-LB: Relative Contribution of Fasting Plasma and Postprandial Glucose to HbA1c and TIR in People with T1D on Basal-Bolus Insulin Therapy

Background: A recent report was published on the contribution of fasting plasma glucose (FPG) and postprandial glucose (PPG) to HbA1c and time in range (%TIR) in people with type 2 diabetes on multiple daily injection regimens using prandial Humalog® (Lispro). We extended this analysis to type 1 diabetes (T1D) using data from people randomized to 26 weeks of mealtime ultra rapid lispro (URLi; N=451), postmeal URLi (N=329) or mealtime Humalog (N=442) in the phase 3 trial, PRONTO-T1D, and its continuous glucose monitoring (CGM) substudy. Methods: A multivariate regression model was used to quantify the contribution of FPG and PPG change to the change in HbA1c and %TIR. The contribution of PPG relative to FPG was determined. %TIR was derived from 10-point self-monitored blood glucose (SMBG) and CGM data from the CGM substudy. Only results for the mealtime groups are presented here. Results: With URLi treatment, a 1 mmol/L reduction in FPG and PPG was associated with a 0.11% ± standard error 0.02% and 0.09% ± 0.01% reduction in HbA1c, respectively, both p