Effect of Exercise Intensity on Exogenous Glucose Requirements to Maintain Stable Glycemia At High Insulin Levels in Type 1 Diabetes.

Abstract

CONTEXT:

Under basal insulin levels, there is an inverted U relationship between exercise intensity and exogenous glucose requirements to maintain stable blood glucose levels in type 1 diabetes (T1D), with no glucose required for intense exercise (80% V̇O2 peak), implying that high-intensity exercise is not conducive to hypoglycemia.

OBJECTIVE:

This work aimed to test the hypothesis that a similar inverted U relationship exists under hyperinsulinemic conditions, with high-intensity aerobic exercise not being conducive to hypoglycemia.

METHODS:

Nine young adults with T1D (mean ± SD age, 22.6 ± 4.7 years; glycated hemoglobin, 61 ± 14 mmol/mol; body mass index, 24.0 ± 3.3 kg/m2, V̇O2 peak, 36.6 ± 8.0 mL·kg-1 min-1) underwent a hyperinsulinemic-euglycemic clamp to maintain stable glycemia (5-6 mmol·L-1), and exercised for 40 minutes at 4 intensities (35%, 50%, 65%, and 80% V̇O2peak) on separate days following a randomized counterbalanced study design.

MAIN OUTCOME MEASURES:

Glucose infusion rates (GIR) and glucoregulatory hormones levels were measured.

RESULTS:

The GIR (± SEM) to maintain euglycemia was 4.4 ± 0.4 mg·kg-1 min-1 prior to exercise, and increased significantly by 1.8 ± 0.4, 3.0 ± 0.4, 4.2 ± 0.7, and 3.5 ± 0.7 mg·kg-1 min-1 during exercise at 35%, 50%, 65%, and 80% V̇O2 peak, respectively, with no significant differences between the 2 highest exercise intensities (P > .05), despite differences in catecholamine levels (P < .05). During the 2-hour period after exercise at 65% and 80% V̇O2 peak, GIRs did not differ from those during exercise (P > .05).

CONCLUSIONS:

Under hyperinsulinemic conditions, the exogenous glucose requirements to maintain stable glycemia during and after exercise increase with exercise intensity then plateau with exercise performed at above moderate intensity ( > 65% V̇O2 peak). High-intensity exercise confers no protection against hypoglycemia.

• Authors: Vinutha B Shetty, Paul A Fournier, Nirubasini Paramalingam, Wayne Soon, Heather C Roby, Timothy W Jones, Elizabeth A Davis
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 106 Issue 1 Pg. e83-e93 (01 01 2021) ISSN: 1945-7197 [Electronic] United States
• PMID: 33097945 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2020. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: [email protected].

Chemical References

• Blood Glucose
• Insulin
• Glucose

Topics

• Adolescent
• Adult
• Blood Glucose (drug effects, metabolism)
• Diabetes Mellitus, Type 1 (blood, complications, drug therapy)
• Dose-Response Relationship, Drug
• Drug Dosage Calculations
• Exercise (physiology)
• Female
• Glucose (administration & dosage)
• Glycemic Control (methods)
• Humans
• Hyperinsulinism (blood, chemically induced, drug therapy)
• Hypoglycemia (blood, etiology, prevention & control)
• Insulin (therapeutic use)
• Male
• Physical Exertion (physiology)
• Western Australia
• Young Adult