<b>Objective</b>: To
compare glucose control with hybrid closed loop (HCL) when challenged by
moderate-intensity exercise (MIE), high-intensity intermittent exercise (HIE)
and resistance exercise (RE) while profiling counter-regulatory hormones,
lactate, ketones, and kinetic data in adults with type 1 diabetes.
<p><b>Methods</b>: <a>Open-label
multisite randomized crossover trial. </a><a>Adults with type 1 diabetes undertook
40 min of HIE, MIE, and RE in random order while using HCL (Medtronic 670G) with
a temporary target set 2 hours prior to and during exercise and 15g carbohydrates
if pre-exercise glucose was <126mg/dL, to prevent hypoglycemia.</a> Primary
outcome was median (IQR) continuous glucose monitoring (CGM) time-in-range
(TIR, 70-180 mg/dL) for 14 hours post-exercise commencement. Accelerometer data and venous glucose, ketones,
lactate, and counter-regulatory hormones were measured for 280 min
post-exercise commencement. </p>
<p><b>Results</b>: Median
TIR was 81%
[67, 93]%, 91% [80, 94]%, and 80% [73, 89]% for 0-14 hours post-exercise commencement for HIE, MIE and RE,
respectively (n=30), with no difference between exercise types (MIE v HIE;
p=0.11, MIE v RE p=0.11, HIE v RE p=0.90). Time-below-range was 0% for all
exercise bouts. For HIE and RE compared with MIE, there
were greater increases respectively in noradrenaline (p=0.01, p=0.004),
cortisol (p<0.001, p=0.001), lactate (p£0.001, p£0.001)
and heart rate (p=0.007, p=0.015). During HIE compared with MIE, there were
greater increases in growth hormone (p=0.024). </p>
<p><b>Conclusions</b>: Under
controlled conditions, HCL provided satisfactory glucose control with no
difference between exercise type. Lactate, counter-regulatory hormones, and
kinetic data differentiate type and intensity of exercise, and their
measurement may help inform insulin needs during exercise. However, their
potential utility as modulators of insulin dosing will be limited by the
pharmacokinetics of subcutaneous insulin delivery. </p>
Home Use of Day-and-Night Hybrid Closed-Loop Insulin Delivery in Suboptimally Controlled Adolescents With Type 1 Diabetes: A 3-Week, Free-Living, Randomized Crossover Trial
