title: Blood glucose responses to reductions in pre-exercise rapid-acting insulin for 24 h after running in individuals with type 1 diabetes.
abstract: In this study, we examined pre-exercise insulin reductions on consequent metabolic and dietary patterns for 24 h after running in individuals with type 1 diabetes. Seven participants self-administered their Full rapid-acting insulin dose or 75%, 50% or 25% of it, immediately before consuming a 1.12-MJ meal. After 2 h, participants completed 45 min of running at 70% peak oxygen uptake ([Vdot]O(2peak)). Blood glucose and insulin were measured for 2 h before and 3 h after exercise. Blood glucose, diet, and administered insulin were self-recorded for 24 h after exercise. Data were analysed using repeated-measures analysis of variance. Pre-exercise peak insulin concentrations were greatest with the Full dose and consequently elicited the lowest blood glucose concentrations (P < 0.05). Blood glucose decreased under all conditions with exercise, with the fall with the Full dose (-6.1 mmol . l(-1), s(x) = 0.4) greater than with 25% insulin (-3.2 mmol . l(-1), s(x) = 0.4; P < 0.05). There was little change in blood glucose from 0 to 3 h post-exercise under all conditions (P > 0.05). Blood glucose at 3 h post-exercise was greatest with the 25% dose. Over the next 21 h, blood glucose area under the curve was greater with the 25% dose compared with all other trials despite consuming less energy and fewer carbohydrates (P < 0.05). A 75% reduction to pre-exercise insulin results in the greatest preservation of blood glucose, and a reduced dietary intake, for 24 h after running in individuals with type 1 diabetes.
authors.affiliation: Sports and Exercise Science Research Centre, Swansea University, Swansea CH-9014, UK. 328181@swansea.ac.uk
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: West
authors.forename: Richard D
authors.initials: RD
authors.lastname: Morton
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Bain
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Stephens
authors.forename: Richard M
authors.initials: RM
authors.lastname: Bracken
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000187:drug effects / Q000502:physiology*; D015992:Body Mass Index; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000378:metabolism; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000008:administration & dosage* / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012420:Running / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin