Glucotoxicity and Acute Exercise

Not Applicable

Withdrawn

• Conditions: Type 2 Diabetes; Type 1 Diabetes
• Interventions: Behavioral: Exercise; Procedure: Hyperglycemia

• Registration Number: NCT01771614
• Lead Sponsor: Rigshospitalet, Denmark

Brief Summary

Experimental hyperglycemia (5 hours) will be induced via a constant- or fluctuating-rate glucose infusion to establish different patterns of glycemia in healthy individuals. The effects of these acute models of hyperglycemia on the adaptations to a single aerobic exercise bout will be tested. Changes in pancreatic endocrine function, insulin sensitivity, endothelial function, and oxidative stress will be measured.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2013-01-16
• Study First Submitted QC: 2013-01-16
• Study First Posted: 2013-01-18
• Study Start: 2016-08
• Primary Completion: 2016-12
• Study Completion: 2017-01
• Status Verified: 2018-05
• Last Update Submitted: 2018-05-15
• Last Update Posted: 2018-05-16

Recruitment & Eligibility

• Status: WITHDRAWN
• Sex: Male
• Target Recruitment: Not specified

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Normoglycemia + exercise	Exercise	At T = 0 h participants will undergo an intravenous glucose tolerance test (IVGTT, 0.33 g/kg glucose) immediately followed by a 4-hour rest period. At T = 5 h, participants will undertake 45 minutes of moderate-intensity (70% VO2max) bicycle ergometry. Immediately following (T = 6 h) and 1- (T = 7 h), 3- (T = 9 h), and 18- hours (T = 24 h) after exercise, participants will undergo additional IVGTTs.
Steady-State Hyperglycemia + exercise	Hyperglycemia	At T = 0 h participants will undergo an intravenous glucose tolerance test (IVGTT, 0.33 g/kg glucose) immediately followed by a 4-hour rest period. During this time, steady-state hyperglycemia (\~10 mM) will be induced experimentally via a variable-rate intravenous infusion of 20% dextrose. At T = 5 h, participants will undertake 45 minutes of moderate-intensity (70% VO2max) bicycle ergometry. Immediately following (T = 6 h) and 1- (T = 7 h), 3- (T = 9 h), and 18- hours (T = 24 h) after exercise, participants will undergo additional IVGTTs.
Fluctuating Hyperglycemia + exercise	Hyperglycemia	At T = 0 h participants will undergo an intravenous glucose tolerance test (IVGTT, 0.33 g/kg glucose) immediately followed by a 4-hour rest period. During this time, fluctuating hyperglycemia (\~8-15 mM) will be induced by intravenously injecting 0.15 g/kg boluses of 20% dextrose every 30 minutes. At T = 5 h, participants will undertake 45 minutes of moderate-intensity (70% VO2max) bicycle ergometry. Immediately following (T = 6 h) and 1- (T = 7 h), 3- (T = 9 h), and 18- hours (T = 24 h) after exercise, participants will undergo additional IVGTTs.
Steady-State Hyperglycemia + exercise	Exercise	At T = 0 h participants will undergo an intravenous glucose tolerance test (IVGTT, 0.33 g/kg glucose) immediately followed by a 4-hour rest period. During this time, steady-state hyperglycemia (\~10 mM) will be induced experimentally via a variable-rate intravenous infusion of 20% dextrose. At T = 5 h, participants will undertake 45 minutes of moderate-intensity (70% VO2max) bicycle ergometry. Immediately following (T = 6 h) and 1- (T = 7 h), 3- (T = 9 h), and 18- hours (T = 24 h) after exercise, participants will undergo additional IVGTTs.
Fluctuating Hyperglycemia + exercise	Exercise	At T = 0 h participants will undergo an intravenous glucose tolerance test (IVGTT, 0.33 g/kg glucose) immediately followed by a 4-hour rest period. During this time, fluctuating hyperglycemia (\~8-15 mM) will be induced by intravenously injecting 0.15 g/kg boluses of 20% dextrose every 30 minutes. At T = 5 h, participants will undertake 45 minutes of moderate-intensity (70% VO2max) bicycle ergometry. Immediately following (T = 6 h) and 1- (T = 7 h), 3- (T = 9 h), and 18- hours (T = 24 h) after exercise, participants will undergo additional IVGTTs.

Primary Outcome Measures

Name	Time	Method
Pancreatic endocrine function	0, 6, 7, 9, and 24 hours	The plasma insulin, C-peptide, and glucagon responses to a 0.33 g/kg intravenous glucose tolerance test (IVGTT) will be measured. In each trial, the IVGTT will be performed at T = 0, 6, 7, 9, and 24 hours.

Secondary Outcome Measures

Name	Time	Method
Oxidative stress	24 hours	Urine will be collected over the whole 24-hour period of each trial and 8-iso Prostaglandin F3α will be measured.
Endothelial function	0, 6, 7, 9, and 24 hours	Blood flow and flow-mediated dilation by Doppler ultrasound will be measured in each trial at T = 0, 6, 7, 9, and 24 hours.
Glucose tolerance	0, 6, 7, 9, and 24 hours	Glucose tolerance will be measured during an IVGTT in each trial at T = 0, 6, 7, 9, and 24 hours.

Trial Locations

Locations (1)

University of Birmingham; 🇬🇧 Birmingham, West Midlands, United Kingdom