Evaluation of glucose control when a new strategy of increased carbohydrate supply is implemented during prolonged physical exercise in type 1 diabetes
- 621 Downloads
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.
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.
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.
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.
KeywordsBlood glucose Carbohydrates CGM Diabetes mellitus type 1 Exercise Hypoglycemia Insulin
Continuous glucose monitoring
Continuous subcutaneous insulin infusion
Type 1 diabetes
This work was supported by unrestricted Grants from Novo Nordisk Scandinavia.
Compliance with ethical standards
Conflict of interest
Peter Adolfsson is one of the founders and a board member of Diasend.
- Black SE, Mitchell E, Freedson PS, Chipkin SR, Braun B (2005) Improved insulin action following short-term exercise training: role of energy and carbohydrate balance. J Appl Phys (Bethesda, MD: 1985) 99(6):2285–2293Google Scholar
- Chokkalingam K, Tsintzas K, Snaar JE, Norton L, Solanky B, Leverton E, Morris P, Mansell P, Macdonald IA (2007) Hyperinsulinaemia during exercise does not suppress hepatic glycogen concentrations in patients with type 1 diabetes: a magnetic resonance spectroscopy study. Diabetologia 50(9):1921–1929CrossRefPubMedGoogle Scholar
- Hållmarker U (2014) Personal communication. Report regarding the Vasalopp: participants with diabetes. MoraGoogle Scholar
- McMahon SK, Ferreira LD, Ratnam N, Davey RJ, Youngs LM, Davis EA, Fournier PA, Jones TW (2007) Glucose requirements to maintain euglycemia after moderate-intensity afternoon exercise in adolescents with type 1 diabetes are increased in a biphasic manner. J Clin Endocrinol Metab 92(3):963–968CrossRefPubMedGoogle Scholar
- Rabasa-Lhoret R, Bourque J, Ducros F, Chiasson JL (2001) Guidelines for premeal insulin dose reduction for postprandial exercise of different intensities and durations in type 1 diabetic subjects treated intensively with a basal-bolus insulin regimen (ultralente-lispro). Diabetes Care 24(4):625–630CrossRefPubMedGoogle Scholar
- Schonfelder M, Hinterseher G, Peter P, Spitzenpfeil P (2011) Scientific comparison of different online heart rate monitoring systems. Int J Telemed Appl 2011. Article ID: 631848Google Scholar
- Yardley JE, Iscoe KE, Sigal RJ, Kenny GP, Perkins BA, Riddell MC (2013) Insulin pump therapy is associated with less post-exercise hyperglycemia than multiple daily injections: an observational study of physically active type 1 diabetes patients. Diabetes Technol Ther 15(1):84–88CrossRefPubMedGoogle Scholar