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Clinical Trial ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Endocrinol. | doi: 10.3389/fendo.2019.00571

Carbohydrate loading followed by high carbohydrate intake during prolonged physical exercise and its impact on glucose control in individuals with diabetes type 1 - an exploratory study

  • 1Örebro University, Sweden
  • 2School of Medical Sciences, Örebro University, Sweden
  • 3Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden

Prolonged physical exercise (PE) is a challenge in type 1 diabetes with an increased incidence of both hypoglycemia and hyperglycemia.
To evaluate the impact of two consecutive days of carbohydrate (CHO) loading, followed by high intermittent CHO-intake during prolonged PE, facilitated by a proactive use of Real-Time Continuous Glucose Monitoring (rtCGM), on glucose control in individuals with type 1 diabetes.

Ten physically active individuals with type 1 diabetes were invited to participate in a 3-day long sports camp with the objective to evaluate CHO-loading and high intermittent CHO-intake during prolonged PE. 1.5 months later the same procedure was evaluated in relation to a 90 km cross-country skiing race (Vasaloppet). Participants were instructed to act proactively using rtCGM with predictive alerts to maintain sensor glucose values within target range, defined as 72-180 mg/dl (4-10 mmol/l).

Mean glucose values during CHO-loading were: day 1; 140.4±45.0 mg/dl (7.8±2.5 mmol/l) and day 2; 120.6±41.4 mg/dl (6.7±2.3 mmol/l). Mean sensor glucose at start of PE was 126.0±25.2 mg/dl (7.0±1.4 mmol/l) and throughout PE 127.8±25.2 mg/dl (7.1±1.4 mmol/l). Percentage of time spent in range (TIR) respective time spent in hypoglycemia was: CHO-loading 74.7/10.4% and during PE 94.3/0.6%.

High intermittent CHO-intake during prolonged PE combined with proactive use of rtCGM is associated with good glycemic control during prolonged exercise in individuals with diabetes type 1. However, the time spent in hypoglycemia during the 2-days of CHO-loading was 10.4% and therefore a lower basal insulin rate might be suggested to reduce the time spent in hypoglycemia.

Keywords: Blood Glucose, Carbohydrates, continous glucose monitoring, Insulin, physical activity, time in range, type 1 diabetes

Received: 05 Nov 2018; Accepted: 06 Aug 2019.

Edited by:

Ondřej Šeda, Charles University, Czechia

Reviewed by:

Jan Brož, Second Faculty of Medicine, Charles University, Czechia
Heikki O. Tikkanen, University of Eastern Finland, Finland
George A. Brooks, University of California, Berkeley, United States  

Copyright: © 2019 Mattsson, Jendle and Adolfsson. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Mr. Stig A. Mattsson, Örebro University, Örebro, Sweden,