Altitude and Type 1 Diabetes
As you may already know, travel in general can have a big impact on type 1 diabetes management. This is typically due to elements such as stress hormones, time change and other shifts in routine that can cause blood sugar levels to behave differently.
However, there are other things to consider when taking trips or exploring the outdoors that might not occur to us right away—such as changes in altitude. The most important thing to remember when planning to journey some place at a higher altitude is that nobody is affected the same way, so it is best to be prepared for multiple outcomes.
By far the most common side effect of being at high altitudes is altitude sickness, which can then lead to (or simulate) other symptoms that can affect type 1 diabetes (T1D) management.
Common symptoms of altitude sickness include:
- shortness of breath
- rapid heartbeat
All of this is due to the decrease in oxygen, but these symptoms are also common when suffering from hypoglycemia (low blood sugar!). So it is important to test blood sugar levels often to distinguish between the two.
Blood sugar levels
- Hypoglycemia: There is no direct evidence that altitude causes low blood sugar, but as previously mentioned, altitude symptoms can feel quite similar. Also, increased exercise (if hiking or walking a lot while in high altitudes), can definitely lead to lows.
- Hyperglycemia: High altitudes can increase your body’s production of stress-related hormones which can raise blood sugar levels. If you plan on hiking or traveling to notably higher altitudes, talk to your doctor about adjusting your insulin doses to compensate for its impact on your blood sugar levels.
There have been studies that suggest that higher altitudes can cause insulin resistance due to carbohydrates not being metabolized as effectively and due to an increase in stress hormones. This can be another cause of high blood sugar and it can also lead to ketones/ketoacidosis in extreme cases. Talk to your doctor about adjusting insulin doses to compensate for high altitude exercising or traveling.
Blood glucose meters, continuous glucose monitors (CGMs) and pumps have been known to not work as effectively in high altitudes. CGMs in particular do not function well in cold weather, so it important to check blood sugar levels manually often. Some meters also do not work properly above a certain height, so it is advisable to check with your meter and/or CGM manufacturers for further guidance.
There have been instances where certain insulin pumps deliver slightly more insulin at high altitudes and on airplanes, so be sure to read your pump manual or check with your pump manufacturer to learn more about how to avoid increased insulin delivery (which can lead to low blood sugars levels!).
Other things to consider
- It is always a good idea to meet with your endocrinologist before traveling, especially to high altitudes. They may be able to provide you with medication to prevent altitude sickness, as well as advise for insulin dosing adjustments.
- Take your time! Altitude sickness is most commonly caused by ascending too quickly. Be sure to keep a steady pace so that your body can acclimate—and take many breaks.
- The higher you climb, the less oxygen there will be. Keep this in mind to avoid exhaustion.
- Be prepared! Pack extra supplies, insulin, water, snacks and quick sugar!