EASD and ISPAD join forces for a new position statement: How to use AID systems around exercise in type 1 diabetes

Physical activity poses many challenges to people living with type 1 diabetes. A recently published position statement offers practical recommendations for the use of automated insulin delivery (AID) systems around planned and unplanned exercise, introducing five key strategies and a detailed assessment of currently available AID systems.

Managing blood glucose levels and physical activity is one of the biggest daily challenges for people with type 1 diabetes (T1D). For users of automated insulin delivery (AID) systems, comprehensive guidance has been lacking. Othmar Moser and Dessi P. Zaharieva are co-lead authors of a new position statement on exercise and AID systems by the European Association for the Study of Diabetes (EASD) and the International Society for Pediatric and Adolescent Diabetes (ISPAD), published in Diabetologia. They emphasise the need for tailored strategies that cannot be extrapolated from existing literature on traditional insulin pumps. As a result, the statement provides practical recommendations for children, adolescents, and adults as well as a broad range of scenarios – even including more challenging activities such as scuba diving and Ironman competitions.

Key recommendations for AID users

Exercise complicates diabetes management due to blood glucose fluctuations, especially if it is unplanned. “If you can pre-plan for exercise, make the adjustments that are necessary in advance. If you can’t pre-plan, make those adjustments immediately at the start of exercise, but it will take trial and error,” says Zaharieva in an episode of EASD e-learning Diabetes Perspectives discussing the new position statement.

It is particularly important that people with T1D understand their individual response to different levels of physical activity and translate this into personalised self-management. Nevertheless, the authors suggest five general strategies (see the original paper for full recommendations):

1. For planned physical activity, set a higher glucose target if a decrease or stable glucose is expected, or maintain a regular or lower glucose target if a glucose increase is expected.
2. For planned physical activity within 2 hours of a carbohydrate (CHO)-rich meal, reduce the prandial bolus insulin if a decrease in glucose is expected. (Higher glucose targets should be initiated before reducing prandial bolus insulin doses.)
3. Pay close attention to CGM (continuous glucose monitor) readings and trend arrows and initiate small amounts of fast-acting CHO intake if the sensor glucose is low during the activity. (Be aware of the risk of hyperglycaemic events, which may trigger subsequent AID-induced hypoglycaemia.)
4. For unplanned physical activity, set a higher glucose target immediately at the onset of activity if a decrease or stable glucose is expected and consume fast-acting CHO if the sensor glucose is low, or maintain a regular or lower glucose target if a glucose increase is expected.
5. Where possible, plan for physical activity when the insulin on board is low. Low-intensity physical activity is recommended when glucose levels are elevated after meals. Physical activity should be avoided if glucose is >15.0 mmol/l and blood ketones are >1.5 mmol/l.

Glucose responses: decrease, stable, or increase

Exercise does not always lead to lower glucose levels. “Many times, we see stress responses in competitive settings that cause blood glucose levels to rise,” says Zaharieva, explaining the relationship between glucose responses and the type and setting of a physical activity (see Figure 1).

Generally, for glucose levels below 15.0 mmol/l, higher glucose targets are recommended, and CHO snacks may be considered. For glucose levels above 15.0 mmol/l, higher glucose targets may not be needed, but CHO snacks should be considered during exercise if glucose levels fall below 7.0 mmol/l. A key challenge, highlighted by Zaharieva and Moser, is preventing AID systems from increasing insulin at the onset of exercise. This can occur due to either a CHO snack or a reduction in prandial insulin before exercise, thus potentially elevating the risk of hypoglycaemia.

System-specific insights

In addition to these strategies, the core of the position statement is a detailed review of the available AID systems. This includes an assessment of their respective evidence for glycaemic control and specific recommendations for use in relation to physical activity. “It was extremely difficult for us to gather all the information for each AID system,” says Moser, adding that he believes the most valuable aspect of the position statement is that it is “absolutely specified for each commercially available system.” The result is a practical and easy-to-use statement that both professionals and people with diabetes can now incorporate into their daily routines.

Find out more from co-lead authors Othmar Moser and Dessi P. Zaharieva in Diabetes Perspectives.

To read the position statement visit: Moser, O., Zaharieva, D.P., Adolfsson, P. et al. The use of automated insulin delivery around physical activity and exercise in type 1 diabetes: a position statement of the European Association for the Study of Diabetes (EASD) and the International Society for Pediatric and Adolescent Diabetes (ISPAD). Diabetologia (2024). https://doi.org/10.1007/s00125-024-06308-z

Author: Hanna Gabriel, BA MSc. Any opinions expressed in this article are the responsibility of EASD e-Learning.