Background and Aims
With the clinical implementation of hybrid closed-loop (HCL) systems, efforts are moving towards personalised medicine. However, sparse evidence exists on how individual carbohydrate (CHO) intake affects glycaemic control in type 1 diabetes (T1D). The HCL-device MiniMed 670G requires CHO-input for meal-time bolus calculation while in “auto-mode”. We aimed at assessing glycaemic control as a function of individual daily CHO-intake.
Between 11/2018 and 06/2019, we evaluated CHO-intake (g/day) and CGM data in adults with T1D using the MiniMed 670G system at our tertiary referral centre. Mean individual daily CHO-intake (MIDC) was assessed for each participant. For each day, the relative deviation from MIDC (rMIDC) was calculated, and days were stratified into low, medium and high CHO-days (≤80%, 81–120% and >120% rMIDC, respectively). CGM read-outs were used to calculate time in target range (TIR, 3.9-10.0 mmol/l), time above target range, and time below target range.
We included 21 patients with T1D (11 male, 10 female; age 39.2±14.7y; HbA1c 7.0±0.9%) providing a total of 879 days of data (mean 42.0±39.2d per patient, 9-186d). Mean individual time in auto-mode was 97.5±4.7%. Time in target range (TIR) for the low, medium and high CHO-days was 82.1±13.9%, 79.2±14.9% and 75.8±14.6%, respectively (p<0.001). Time above target range was 15.8±13.1%, 18.8±14.3% and 22.6±14.7%, respectively (p<0.001). There was no significant difference for time below target range.
Individual daily CHO-intake was inversely associated with glycaemic control in adults with T1D using the MiniMed 670G HCL-system, corroborating the importance of personalised treatment recommendations.