Evaluation of glucose control when a new strategy of increased carbohydrate supply is implemented during prolonged physical exercise in type 1 diabetes.
OBJECTIVE
In healthy individuals, high carbohydrate intake is recommended during prolonged exercise for maximum performance. In type 1 diabetes (T1D), this would alter the insulin requirements. The aim of the study was to evaluate the safety of high glucose supplementation during prolonged exercise and the glucose control when a novel strategy of increased carbohydrate supply was implemented during prolonged exercise in T1D.


METHODS
Eight subjects with T1D participated in a sports camp including sessions of prolonged exercise and individualized feedback during three consecutive days. This was later followed by a 90 km cross-country skiing race. Large amounts of carbohydrates, 75 g/h, were supplied during exercise and the insulin requirements were registered. Glucose was measured before, during and after exercise aiming at euglycaemia, 4-8 mmol/L (72-144 mg/dL). During the race, continuous glucose monitoring (CGM) was used as an aspect of safety and to allow direct and individual adjustments.


RESULTS
Compared to ordinary carbohydrate supply during exercise, the high carbohydrate supplementation resulted in significantly increased insulin doses to maintain euglycaemia. During the cross-country skiing race, the participants succeeded to reach mean target glucose levels; 6.5 ± 1.9 mmol/L (117 ± 34 mg/dL) and 5.7 ± 1.5 mmol/L (103 ± 27 mg/dL) at the start and finish of the race, respectively. Episodes of documented hypoglycemia (<4 mmol/L/72 mg/dL) were rare. CGM was used for adjustments.


CONCLUSIONS
In this study, large carbohydrate supplementation in T1D individuals during prolonged aerobic exercise is safe and allows the subjects to maintain glycaemic control and indicates the feasibility of CGM under these conditions.
Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. peter.adolfsson@regionhalland.se.|Endocrine and Diabetes Center, The hospital of Halland Kungsbacka, Kungsbacka, Sweden. peter.adolfsson@regionhalland.se.
Peter
http://orcid.org/0000-0001-7615-9737
P
Adolfsson
Faculty of Health Sciences and Medicine, Örebro University Hospital, Örebro, Sweden. stig.mattsson@ltdalarna.se.|Endocrine and Diabetes Center, Falun Hospital, Falun, Sweden. stig.mattsson@ltdalarna.se.
Stig
S
Mattsson
Faculty of Health Sciences and Medicine, Örebro University Hospital, Örebro, Sweden. johan.jendle@liv.se.|Endocrine and Diabetes Center, Karlstad Hospital, Karlstad, Sweden. johan.jendle@liv.se.
Johan
J
Jendle
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D004040:Dietary Carbohydrates
Blood glucose; CGM; Carbohydrates; Diabetes mellitus type 1; Exercise; Hypoglycemia; Insulin