1054-P: Insulin Sensitivity from Sensor and Pump Data in Youths with Type 1 Diabetes: Hybrid Closed-Loop Validation

Abstract

Estimate of insulin sensitivity (SI) and its daily variation are essential for optimizing insulin therapy in type 1 diabetes (T1D). Recently, a SI index based on continuous glucose monitoring (CGM) and insulin pump (CSII) data (SISP) has been validated in adults with T1D. Herein, we validated the SISP index against the oral minimal model (MM) one (SIMM) during two sequential meals in youth with T1D during hybrid closed-loop (HCL) treatment. Ten youths with T1D (4F; age=20.9±3.7 y; BMI=23.6±4.5 kg/m2; TDD= 50.6±16.3 U/day; HbA1c 7.3±0.6%) underwent two consecutive, standardized meal studies (breakfast, B, and lunch, L) while wearing the UVA-DiAS HCL (Dexcom CGM and t-slim CSII) system. Plasma glucose and insulin concentration data (measured every 10 min for 4 h during each meal) were used for SIMM estimation, while the corresponding CGM and CSII data, derived from the HCL system, were used for SISP calculation. SISP well correlated with SIMM (Fig. 1) for both B (18.1±7.6 vs. 21.5±12.1 10-4dL/kg/min per uU/mL, R=0.70) and L (26.5±10.1 vs. 26.0±13.8 10-4dL/kg/min per uU/mL, R=0.77). Between-meal (L-B) variation of SISP was also well correlated with its MM counterpart (R= 0.82). SISPis a reliable proxy of the oral minimal model derived SI and can be used to customize both open- and closed-loop treatments to improve glycemic outcomes in young people with T1D. Disclosure M. Schiavon: None. A. Galderisi: None. K.A. Kraemer: None. C. Cobelli: None. C. Dalla Man: None. E. Cengiz: Advisory Panel; Self; Abvance, ADOCIA, MannKind Corporation, Novo Nordisk Inc. Speaker's Bureau; Self; Novo Nordisk Inc. Funding JDRF (to E.C.); International Society for Pediatric and Adolescent Diabetes; Patterson Foundation (to A.G.); European Medical Information Framework (to A.G.); University of Padova (to M.S., C.D.M.)