High-altitude exercise may increase the risk of hypoglycemia in people with diabetes

WASHINGTON — People with diabetes may need to monitor their blood sugar more closely when engaging in high-altitude activities such as hiking or skiing, according to a small study published in the Society’s Journal of Clinical Endocrinology & Metabolism .

Doctors often recommend exercise for people with diabetes because it has many benefits. It can improve heart health, insulin sensitivity, and quality of life. However, exercise can also cause hypoglycemia (dangerously low blood sugar levels) in people with diabetes during and after a workout. If a person’s blood sugar level is really dropping, quick action is needed because they may have a seizure, pass out, or die.

“These results suggest that exercise performed soon after exposure to high altitude may increase the risk of exercise-induced hypoglycemia,” said Cory Dugan, AFHEA, B.Sc. (Hons), of the University of Western Australia at Crawley, Australia. “We ask that future guidelines take these findings into account to increase the safety of people with type 1 diabetes when traveling from low to high elevation areas such as mountains without any acclimatization.”

The researchers studied seven people with type 1 diabetes and measured their blood sugar levels before, during and after two sessions of indoor cycling mimicking sea level and high altitude conditions. After an hour of exercise at 4,200 meters (about half the height of Mount Everest) and during recovery, the blood sugar level was significantly lower. These results suggest that exercise at high altitude may increase the risk of hypoglycemia in people with type 1 diabetes.

The other authors of the study are: Shane Maloney, Kristina Abramoff and Sohan Panag of the University of Western Australia; Elizabeth Davis and Timothy Jones of the Telethon Kids Institute in Nedlands, Western Australia; and Paul Fournier from the University of Western Australia and the Telethon Kids Institute.

The study received funding from the National Board of Health and Medical Research.

The manuscript, “Effects of Simulated High Altitude on Blood Sugar Levels During Exercise in People with Type 1 Diabetes,” was published online, ahead of print.