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Feasibility of integrating faster-acting insulin aspart with dose adjustments as part of multiple daily insulin regimen around physical exercise in adults with type 1 diabetes / JASON PITT
Swansea University Author: JASON PITT
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Copyright: The author, Jason Pitt, 2024 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0).
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DOI (Published version): 10.23889/SUThesis.70075
Abstract
The increased metabolic demands of physical exercise place significant stress on blood glucose homeostasis in the effort to supply working muscles with energy substrate. In people with type 1 diabetes (T1D), this adds to the already challenging task of daily glucose control and requires additional m...
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Swansea University, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Bracken, R. M. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa70075 |
| Abstract: |
The increased metabolic demands of physical exercise place significant stress on blood glucose homeostasis in the effort to supply working muscles with energy substrate. In people with type 1 diabetes (T1D), this adds to the already challenging task of daily glucose control and requires additional management strategies to avoid dysglycaemia. Adjusting doses of insulin taken with the meal before exercise is recognised as a key strategy for preserving blood glucose concentrations and avoiding hypoglycaemia. However, the landscape for insulin therapy is in constant motion. Faster-acting insulin aspart (Fiasp) represents the latest generation of mealtime insulins, which have been developed with earlier onsets of appearance, exposure, and peaks than previous insulins. It is therefore of interest to i) evaluate from the available literature how reducing the dose of (previous generation) mealtime insulins prior to exercise affects glycaemia during exercise and ii) to investigate the application of these dose reductions when using Fiasp.There is limited information on the use of Fiasp around exercise. Current studies have not yet investigated the feasibility of administering Fiasp with different dose adjustments as part of multiple daily insulin (MDI) regimen to preserve glucose around exercise. Hence, the overarching aim of this thesis was to identify the glycaemic effects of pre-exercise bolus insulin dose reductions, with application in using Fiasp as part of an MDI regimen in real-world and clinical trial settings in recreationally active individuals and trained athletes with T1D.Three studies were performed (across Chapters 3, 4, and 5 in this thesis) to address this aim.Chapter 3 was a systematic review and meta-analysis of studies in which the protocol made at least one comparison in the rate of change of blood glucose decline during exercise between a full dose and reduced dose of pre-exercise mealtime insulin. The meta-analysis revealed the rate of change of blood glucose during exercise was greater when using a full insulin dose compared to a reduced dose (standardised mean difference = 0.59, CI 95%: 0.17, 1.01;p=0.006). Chapter 4 was an observational exploratory analysis of interstitial glycaemia in professional road cyclists with T1D who performed prolonged endurance training rides using Fiasp and insulin aspart, in addition to a race event using Fiasp only. Time in euglycaemia was similar in the use of Fiasp or insulin aspart (75.8 ± 32.7% vs.76.6 ± 29.6%; p=0.915), alongside all other glucose metrics (all p>0.05). When reducing daily bolus insulin dosing, riders were able to maintain near-target time in range during an international competitive event (68.1 ±9.6%). Chapter 5 was a prospective, two-site, double-blind, randomised, four-arm crossover, clinical trial to compare the effects of Fiasp and insulin aspart across different dose reductionsaround exercise. There were no differences between the decline of blood glucose duringexercise when taking a 50% reduction in Fiasp (-4.0 ± 2.8 mmol.L-1) prior to exercise comparedto a 75% reduction in Fiasp (-2.8 ± 3.3 mmol.L-1), a 75% reduction in insulin aspart (-3.4 ± 3.3mmol.L-1), or a 50% reduction in insulin aspart (-5.1 ± 3.0 mmol.L-1). There was, however, agreater decline in blood glucose when taking the 50% reduction in insulin aspart compared to75% in either insulin.Collectively, this thesis advances the current understanding of i) how pre-exercise dosereductions can influence exercise glycaemia and ii) how Fiasp can be used in people with T1Don MDI regimens when employing dose reduction strategies around exercise. In both acute andprolonged exercise, Fiasp exerts similar glucose-lowering effects to insulin aspart; hence, thesedata indicate that clinicians or the individual with T1D looking to switch between these insulinscan do so without significant impact on exercise-related glycaemia |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Type 1 diabetes, Exercise, Insulin, Blood glucose, Fiasp |
| College: |
Faculty of Science and Engineering |