Short-Acting Insulin Reduction Strategies for Continuous Cycle Ergometer Exercises in Patients with Type 1 Diabetes Mellitus

Abstract

Background: The fear of hypoglycemia is the strongest barrier when patients with type 1 diabetes mellitus consider physical activity. There is still a lack of information regarding pre-and post-exercise therapy adaptation strategies with respect to different exercise intensities corresponding to the three phases of lactate metabolism. Objectives: The aim of this experimental, cross-sectional study was to investigate exercise intensity-dependent, short-acting insulin reductions to avoid hypoglycemia, applying standardized exercises using insulin degludec (®Tresiba/Novo Nordisk, Denmark). Methods: Seven male participants with type 1 diabetes mellitus were switched to insulin degludec. Intensities for the 30 minutes continuous cycle ergometer exercise tests were set at 5% below (A) and above (B) the lactate turn point 1, and below (C) and above (D) the lactate turn point 2. Reductions in short-acting insulin were applied as following: by 25% for intensity A, by 50% for intensity B and by 75% for intensities C and D four hours before the start of exercise and immediately after exercise. Blood glucose, interstitial glucose, lactate, catecholamines, cortisol, IGF-1 and glucagon were measured.

Reduction in insulin degludec dosing for multiple exercise sessions improves time spent in euglycaemia in people with type 1 diabetes: A randomized crossover trial

“…The physiological underpinning mainly lies in the transcription of glucose transport proteins (glucose transporter type 4), its movement and insertion into membranes, facilitating insulin‐independent intramuscular glucose uptake . While blood glucose homeostasis in healthy individuals is regulated via increasing counterregulatory hormones and its effect on hepatic glycogen depletion, glucagon fails to increase in people with T1D and thus to prevent exercise‐induced hypoglycaemia . Furthermore, circulating exogenous insulin levels persist on the basis of its duration of action, which increases the risk of short‐ and long‐term exercise‐induced hypoglycaemia.…”

“…An unaltered usual dose of IDeg can be employed safely as a background insulin if patients wish to engage in low‐, moderate‐ and high‐intensity exercise when applying bolus insulin dose reductions . The risk of hypoglycaemia of an acute bout of exercise may persist for at least 24 hours, driven partly by circulating insulin levels and increased tissue insulin sensitivity .…”

“…6 An unaltered usual dose of IDeg can be employed safely as a background insulin if patients wish to engage in low-, moderate-and high-intensity exercise when applying bolus insulin dose reductions. 7,8 The risk of hypoglycaemia of an acute bout of exercise may persist for at least 24 hours, driven partly by circulating insulin levels and increased tissue insulin sensitivity. 5 Although basal rate reductions are recommended in patients running on continuous subcutaneous insulin infusion, limited data exist on basal insulin dose reductions for multiple dose insulin injections.…”

“…Comparison of 100% insulin degludec (IDeg) and 75%IDeg for glycaemic ranges, hypoglycaemic events, coefficient of variation (CV) and for glycaemia based on the first (first 48 h) and last exercise phase (last 48 h) SD T1D and thus to prevent exercise-induced hypoglycaemia 7. Furthermore, circulating exogenous insulin levels persist on the basis of its duration of action,29 which increases the risk of short-and long-term exercise-induced hypoglycaemia.Interestingly, neither the time of day (daytime or night-time) nor the phase within the 5 exercise days (first 48 hours or last 48 hours) differed significantly when comparing glycaemic ranges, AUC, hypoglycaemic events or glycaemic variably for 100% IDeg versus 75%…”

Performance of the Freestyle Libre flash glucose monitoring (flash GM) system in individuals with type 1 diabetes: A secondary outcome analysis of a randomized crossover trial

“…At the pre‐ and post‐exercise meal, participants consumed 1 g of carbohydrates per kilogram of bodyweight, with a regular dose or 50% dose of bolus insulin. Additionally, a pre‐bedtime snack, consisting of 0.4 g of carbohydrates per kilogram of bodyweight, was consumed without a dose of bolus insulin . The basal insulin dose remained unchanged for the purpose of this study.…”