Updated February 2, 2001

Climbing and mountaineering are dangerous activities for anyone. High altitude climbing is especially dangerous, because in addition to all the hazards you can or cannot control, there are additional health-related issues/risks directly related to the altitude. Proper acclimatization (among other things) is essential for anyone doing high altitude activity and for minimizing altitude-related health risks. It is important to understand the significance and symptoms of altitude-related illness and ways to minimize health risks.

As a diabetic, though, we face many additional challenges which we cannot ignore. Diabetic climbers have died or become very ill in the mountains because they haven't taken necessary precautions or have ignored their diabetes. Dangers for the diabetic climber can result from any number of things related to our disease. High blood sugar (hyperglycemia) has led to diabetic ketoacidosis (DKA), death, and other serious situations at high (and not-so-high) altitudes. High blood sugar and high altitudes both can dehydrate a diabetic rapidly and can accelerate the onset of DKA. There may be some evidence that acetazolamide may block the body's attempt to correct acidosis, too. Death or serious injury has been related to complications from the disease, too (complications affecting eyes, heart, extremity and other major body systems). Low blood sugar (hypoglycemia) can have very serious consequences as well.

To make matters worse, symptoms from hypoglycemia and hyperglycemia (without blood glucose confirmation) can be confused with symptoms of hypothermia or other serious health issues due to hypoxia (and vice-versa) - potentially life-threatening conditions themselves.

As diabetic climbers, we need to adequately answer the "what if's" and develop systems to deal with those contingencies and thoroughly test systems out BEFORE we get into serious situations far from hospitals, far from home, far from our regular pharmacy. Potentially extreme environmental conditions is a huge part of our challenge when managing our diabetes, especially when our tools (blood glucose monitors, insulin delivery devices, insulin) are so affected by the cold. If insulin is frozen it cannot be injected and without it, we die.

We must keep insulin, blood glucose monitors and supplies, insulin pumps and other temperature sensitive supplies in a secure and temperature-friendly place. Our bodies provide an excellent source of heat to keep things warm. To accomplish this I have made a custom bag (I’m currently on my fourth generation of bag) which attaches around my neck and waist and allows me to monitor blood sugar while my blood glucose monitor stays secured in the bag. This bag also keeps my insulin, pump, strips, lancet device (on a lanyard) close at hand and protected from extreme cold. If you make one for yourself, make sure to test it out before going into the mountains and/or backcountry.

Also, there are many universal concerns when it comes to blood glucose monitoring at altitude. First, is the fact that no blood glucose monitor manufacturer will make claims as to the accuracy of their products at extreme altitudes (above 5000 meters) and the United States Food & Drug Administration officially states that monitors may be inaccurate at very high altitudes. The next, perhaps most important issue, is the cold. Blood glucose monitors are affected by temperature, some more than others, and should be used under recommended operating conditions. Not all blood glucose monitors are appropriate for use at high altitudes.

There are many variables that ultimately effect the amounts of insulin we need and our resulting blood sugars. Of course exercise is always an important factor, regardless of the altitude one is at. At altitude (and away from home), however, we must also consider that it can be impossible to eat both the quantity and quality of food we would be able to consume at lower elevations or at home. Also, at altitude and in cold environments our digestive systems don’t function as efficiently as they do at lower and warmer places. The rate of carbohydrate/glucose absorption into our blood stream in these environments has been observed (by me and other IDEA 2000 expedition members) to be MUCH slower - particularly true for evening or dinner-time meals. What this means in terms of glycemic control for diabetics using lispro (Humalog), is that with a "normal" bolus (commensurate to the carb to be eaten), one may very well experience hypoglycemia very soon after injection or bolusing and hyperglycemia later on in the night when lispro is no longer active and carbohydrates are being slowly absorbed. There are a number of possible solutions for accounting for this delay in glucose absorption and you are the best person to decide for how to do this. Remember that frequent blood glucose monitoring is very important (and taking appropriate action as necessary) and a reduction in dinner-time boluses may be appropriate with follow-up boluses or other methods to properly cover slowly absorbed carbohydrates.

In addition, there may be evidence (also anecdotal at this point) that there are other factors which can affect glycemic control of diabetics at high altitude. A number of diabetic climbers have experienced rises in blood glucose levels when exerting themselves at altitude, though this is not very well understood nor has it been scientifically explained. For me personally I believe that my basal insulin needs also go up, the higher elevation I go and the less acclimatized I am. The basic question of whether insulin needs go up at altitude is presently being studied by IEMM – through anecdotal experience during our expedition to Aconcagua and also in controlled hypobaric (high-altitude simulated) conditions.

Part of being a successful mountaineer (having fun, reaching beautiful summits and returning home) is being prepared for the unexpected - through training, experience, planning, etc. This is similar to our need as diabetic mountaineers for being prepared for the unexpected regarding our diabetes. We need to have alternate/backup monitoring methods and supplies available (e.g., visual strips, an additional meter, spare batteries, etc) and fast acting carbohydrates in one or more pockets which we (and our partners) can always access.

Taking care of my diabetes is what I MUST do to live a healthy life and continue climbing mountains. My climbing partners are aware of this fact, support this conviction, and are able to help me because I have taught them how.

Being prepared for the unexpected and coming home to climb another day is what it's all about.