Volume 2015 Supplement 1

Abstracts from the 8th APPES Biennial Scientific Meeting

Open Access

Effect of exercise intensity and blood glucose level on glucose requirements to maintain stable glycaemia during exercise in individuals with type 1 diabetes

  • Shetty Vinutha1, 2,
  • Fournier Paul3,
  • Davey Raymond2, 4,
  • Retterath Adam4,
  • Roby Heather4,
  • Paramalingam Nirubasini1, 4,
  • Cooper Matthew4,
  • Davis Elizabeth1, 2, 4 and
  • Jones Timothy1, 2, 4
International Journal of Pediatric Endocrinology20152015(Suppl 1):O39

https://doi.org/10.1186/1687-9856-2015-S1-O39

Published: 28 April 2015

Current recommendations for carbohydrate supplementation to prevent exercise-induced hypoglycaemia in individuals with type 1 diabetes (T1D) do not take into account exercise intensity or blood glucose levels during exercise. The aim of these studies was to investigate the effects of (a) exercise intensity and (b) blood glucose levels, on carbohydrate requirements to maintain stable glycaemia during exercise in individuals with T1D at basal insulin levels and to determine the glucoregulatory mechanisms underlying these effects.

Nine young adults with T1D underwent euglycaemic clamps, whereby stable blood glucose levels between 4.5 to 6mmol/L were maintained during the study at basal insulin levels. Participants performed up to 40 minutes of exercise at four different exercise intensities (35%, 50%, 65% and 80% VO2peak) on four separate days following a randomised counterbalanced design. In a subsequent experiment, eight participants underwent either a euglycaemic or hyperglycaemic (9.5 – 10.5mmol/L) clamp at basal insulin levels, during which they performed 40 minutes of exercise at 50% VO2peak, on two separate days. In both studies, glucose infusion rates (GIR) to maintain stable glycaemia were measured during exercise, constant deuterated glucose was infused to determine glucose kinetics and blood samples were collected for the analysis of glucoregulatory hormones.

The average GIR to maintain euglycaemia during exercise was 2.0±0.9, 4.0±1.5, and 4.1±1.7g/h (mean±SEM) at 35%, 50% and 65% VO2peak, respectively. These GIRs were all significantly greater than that at 80% VO2peak where no glucose was required (p<0.05). Exercise at 80% VO2peak was associated with a significant rise in catecholamine levels and endogenous glucose production (p<0.05). The average GIR to maintain stable glycaemia during exercise performed during the second experiment at 50% VO2peak was similar at euglycaemia (4.9±2.1g/h) and hyperglycaemia (5.5±2.5g/h; p>0.05).

At basal insulin levels, the relationship between exercise intensity and the amount of glucose required to prevent hypoglycaemia is not linear, with no glucose required to maintain euglycaemia during high-intensity exercise. Performing moderate-intensity exercise at euglycaemia or mild hyperglycaemia does not alter the glucose requirements to maintain stable glycaemia.

Authors’ Affiliations

(1)
Department of Endocrinology and Diabetes, Princess Margaret Hospital
(2)
School of Paediatrics and Child Health, University of Western Australia (UWA)
(3)
School of Sport Science, Exercise and Health, UWA
(4)
Telethon Kids Institute, UWA

Copyright

© Vinutha et al; licensee BioMed Central Ltd. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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