Acute hyperglycemia does not impair exercise performance in type 1 diabetes: Study

In individuals with type 1 diabetes, chronic hyperglycemia impairs aerobic fitness. However, the effect of acute marked hyperglycemia on aerobic fitness is unclear, and the impact of insulin level has not been examined.

A study was conducted by a group of researchers from Australia to explore whether acute hyperglycemia with higher or low insulin levels affect V˙O2peak and other exercise performance indicators in individuals with type 1 diabetes.

In this study, the researchers selected type 1 diabetic patients within the age group of 14–30-year-old.

All the participants exercised in a clinical laboratory under three clamp (constant insulin, variable glucose infusion) conditions on separate days:

· Euglycaemia (5 mmol/l) with 20 mu [m2 BSA]−1 min−1 insulin (where BSA is body surface area) (Eu20)

· Hyperglycaemia (17 mmol/l) with 20 mu [m2 BSA]−1 min−1 insulin (Hyper20)

· Hyperglycaemia (17 mmol/l) with 5 mu [m2 BSA]−1 min−1 insulin (Hyper5).

The results of the study were as follows:

• In total 12 recreationally active individuals with type 1 diabetes were analyzed.
• Compared with Eu20, V˙O2peak was lower in Hyper20, but Hyper5 was not different.
• Compared with Eu20, sprint cycling peak power was not different in Hyper20 but was higher in Hyper5.
• Hyper20 reaction times were not different but Hyper5 reaction times were slower than Eu20.
• No differences between Eu20 and either the hyperglycaemic condition were observed for the other testing measures.

Acute hyperglycemia had an insulin-dependent effect on sprint cycling absolute power output and reaction time but with differing directionality (positive for sprint cycling and negative for reaction time) and no effect on the other indicators of exercise, performance examined. Thus, the researchers concluded that acute hyperglycemia is not consistently adverse and does not affect total exercise performance to an extent clinically relevant for recreationally active individuals with type 1 diabetes.

Reference:

Acute hyperglycemia does not have a consistent adverse effect on exercise performance in recreationally active young people with type 1 diabetes: a randomized crossover in-clinic study by Rothacker K et. al published in the Diabetologia.

https://doi.org/10.1007/s00125-021-05465-9