Dale Morrison, Australia

University of Melbourne St Vincent's Hospital department of Medicine

Presenter of 1 Presentation

KINETICS OF CONTINUOUSLY MEASURED INTERSTITIAL VERSUS VENOUS LACTATE FOLLOWING HIGH INTENSITY EXERCISE IN ADULTS WITH TYPE 1 DIABETES

Session Name
ARTIFICIAL PANCREAS
Session Type
E-POSTER VIEWING (EXHIBITION HOURS)
Date
20.02.2020, Thursday
Session Time
09:30 - 15:30
Channel
E-Poster Area
Lecture Time
09:47 - 09:48

Abstract

Background and Aims

Exercise remains challenging to current generation closed-loop (CL) systems relying on glucose as the sole measured input determining insulin delivery. Interstitial lactate may be an additional signal modulating insulin delivery with exercise. We aimed to explore the feasibility of continuous interstitial lactate measurements and their relationship to venous lactate in individuals with T1D during exercise.

Methods

Six adults with T1D (mean ± SD; age: 40.0 ± 9.5y; HbA1c: 7.6 ± 1.3%) had a prototype optochemical continuous lactate monitor (CLM) inserted subcutaneously in their flank. All participants undertook 40min high intensity exercise. Forearm venous samples for lactate measurement by YSI analyser were collected at 20min intervals from exercise commencement until 240min post-exercise. Exploratory comparisons between CLM and venous lactate profiles included comparisons of time-to-peak and lag-time.

Results

Preliminary data was analysed from six participants. Unacceptable signal loss occurred in two participants post-exercise, with data only included for time-to-peak analysis. There was high variability in lag-time of CLM versus venous lactate, with a difference in time-to-peak ranging from -11 (faster in CLM) to +47 min (n=6) and lactate clearance ranging from -40 (faster in CLM) to +114min (n=4).

Conclusions

This early data suggests that interstitial lactate as measured by a prototype CLM in T1D participants undertaking high intensity exercise mirrored the rise and fall in venous lactate with variable lag. This lag appeared greater when lactate levels were falling post-exercise. These differences between interstitial and venous lactate may have implications for interstitial lactate as a CL additional signal candidate.

clm graph.png

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