Mealtime or Post-meal Dosing of URLi in Medtronic 780G Hybrid Closed Loop System

This is a pilot study to compare premeal to postmeal dosing of ultra rapid lispro insulin (URLi) used in a MiniMed 780G system hybrid closed loop system. Subjects with type 1 diabetes mellitus (T1DM) already using a 780G hybrid closed loop system with URLi will be included. After signing a remote digital informed consent, a baseline record of the MiniMed 780G system will be downloaded from the Medtronic digital platform (Carelink system \[1\]) and subjects will be asked to fill an online questionnaire regarding their time of insulin dosing preferences and a 3-day online food diary \[2\]. During the intervention period subjects will be asked to provide a bolus dose of insulin only at the end of meals for up to 4 weeks. During the last week of the intervention period, subjects will be asked to fill out a 3-day online food diary \[2\]. At the end of the intervention period- a Carelink report \[1\] will be collected remotely and subjects will be asked to fill again the online questionnaire regarding their time of dosing preferences. 1. Primary Objective: To assess the efficacy of premeal dosing to post-meal dosing on parameters of glycemic control as obtained from continuous glucose monitoring. 2. Secondary Objective: To assess patient dosing preferences and the effect of premeal dosing vs. post-meal dosing on patient reported outcomes Ref: 1. carelink.medtronic.eu 2. NutRatio.com.