Dealing with the Adrenaline Rush

Type I Diabetics have a very familiar list of suggestions from doctors. The list usually includes exercising regularly, eating a well-balanced diet, monitoring daily blood sugars, taking medication as indicated, and trying to reduce stress.

There are many variations, but regular exercise is one of the items always on the list. ALWAYS.
Despite the eye rolling from patients tired of repetitive doctor nagging it’s very true that exercise is a great way for diabetics to reduce insulin resistance, improve blood circulation and immune response, and make the disease easier to manage overall. So you could imagine the irritation from diabetics that experience unexpected high blood sugar levels when they do finally go out and exercise. By all rationale reasoning, exercise should help lower blood sugar and increase sensitivity to insulin, but there are many times when the blood sugar level goes up.
Why does this happen?...

In high school, I had this problem frequently when playing sports and I always thought it was an unfortunate anomaly. Maybe there was something wrong with me personally. More recently, I was discussing this same topic with JDRF members on a discussion board and I found it was relatively common among some diabetics. We talked about what is possibly causing our bizarre spikes and how we treat the unexpected high blood sugar.

The following is my “too long; didn’t read” synopsis:

Adrenaline with exercise or other forms of stress can increase glucagon secretion and release glycogen, which raises blood sugar levels unexpectedly. In my experience, I correct these irregular blood sugars caused by stress or exercise on the side of caution (~200 mg/dL) to prevent future lows. 

Now I will backtrack a bit to explain the biology of the matter in a bit more detail. Some information here is personal or anecdotal and is only meant to describe basic biology of stress on diabetics.

In a person unaffected by diabetes, glycogen is stored in the liver and released by a hormone call glucagon that is secreted from the pancreas along with insulin. Glycogen is essentially long strands of glucose stored in a tight bundle. Insulin and glucagon act opposite of each other; insulin reduces blood sugar by allowing transport of sugar into cells and glucagon increases sugar by breaking down glycogen into individual pieces of sugar. When blood sugar is high, insulin levels go up and glucagon levels go down. The opposite is true when blood sugar drops.

Type I Diabetics are able to make and store glycogen and can also secrete glucagon to break it down, but that secretion is compromised by not quite well defined mechanisms. Some researchers believe glucagon isn’t controlled properly in diabetics because of a lack of intra-islet insulin secretion; diabetics inject insulin subcutaneously rather than have it produced on the pancreas’ islet cells. Other scientists believe glucagon secretion is simply suppressed by higher than normal blood sugar commonly found in diabetics. Regardless, glucagon secretion is typically low for diabetics, which is why in emergency low blood sugar situations diabetics have an emergency shot of glucagon.

Normally, glucagon secretion is in response to the body needing energy or when blood sugar drops. Glucagon secretion would leads to glycogen breakdown and a rise in blood sugar. Exercise does generally lower blood sugar, but during exercise I don’t always have an unexpected rise. Sometimes blood sugar drops and sometimes blood sugar rises.

If I’m casually biking around town, my blood sugar drops. If I’m jogging in the park, my blood sugar drops. If I’m playing soccer on a team in high, my blood sugar jumps. If I’m at a wrestling match, my blood sugar can become really high. So what could be causing blood sugar to sometimes rise during exercise and sometimes drop?

It’s the adrenaline rush that people sometimes feel in competition. During the body’s “fight or flight” response, the adrenal glands are turned on and pump out other hormones to prepare the body for action. Adrenaline is one of the well-known hormones released during stressful moments such as in the heat of a competitive match of tennis or football. Adrenaline works to prepare the body for a predicted huge need for energy by reducing insulin secretion and breaking down glycogen in the liver by increasing glucagon secretion. For a diabetic, reducing insulin secretion isn’t really a problem because most people believe diabetics aren’t producing significant amounts of insulin anyway.

I’ve felt this rush during a tough match in high school. It’s very intense and the effect on my blood sugar is very real. At the peak of a wrestling tournament, I could find myself with a blood sugar reading of >350 mg/dL. But on a relaxing non-competitive bike ride through the forest, I actually find my blood sugar drops, as I would expect.

Bizarre jumps in blood sugar aren’t limited to sports. Most people have felt that same adrenaline rush in many different scenarios, such as during an exam, on a first date, or when stuck in an elevator. In fact, I recall being in a car accident and having a blood sugar >500 mg/dL. Our body is simply trying to make sure we have all the energy we need in the form of sugar in the bloodstream. Normally, the body would be able to properly regulate this balance with a biological rheostat, but a diabetic isn’t able to and we end up with high blood sugar.

To compound the issue, cortisol is another hormone released by the adrenal glands. Cortisol reduces transport of sugar into cells and increases a process called gluconeogenesis – the process of creating sugar from proteins and fats. These combined processes, along with cortisol’s functions on the inflammation and immune responses, ensure the bloodstream will have sugar to spare when muscles need it. Unfortunately, this adds to the unwanted blood sugar increases in diabetics.

The body and endocrine system is a highly effective machine with checks and balances teetering back and forth. For Type I Diabetics, we have a deregulated cog and in this scenario, the machine acts against us and causes trouble. We need to correct for these unwanted and unexpected highs.

The magnitude of increase and duration of stress is highly variable. There is no accurate measure to estimate the amount of change or how long the increasing blood sugar will continue, which makes it difficult to prepare for and correct.

In my personal experience, I check my blood sugar frequently during those stressful times like sports matches and job interviews, and I cautiously correct to 200 mg/dL using my normal correction ratio. I correct to 200 mg/dl rather than 100 mg/dL because I know at some point the adrenaline will subside and I’ll be exerting a physical or mental stress that may lower my blood sugar.

All in all, this is an unanticipated burden for many Type I Diabetics. However, knowing when it may happen and why it is happing can sometimes help us decide how to treat the problem. Another message to this biology lesson is that so much of our body is interconnected and that the advice from doctors to diabetics, whether it’s repetitive or not, it true. Exercise is hugely beneficial to daily life and hopefully you can also see how reducing stress can improve control.

Sometimes I like to me reminded of the “why” and not just the “what”. After talking with some of my diabetic friends, I thought this topic was useful to talk about. Not only as a basic biology lesson, but also as a way to illustrate that open discussion can illuminate so much at times.