Diabetes, cycling and technology

Note:  I first wrote and posted this article to my blog at VeloReviews.com on June 15, 2010.  Since then, I’ve imported it back here to JustAnotherCyclist.com to provide more context to posts that will be appearing here.

I generally don’t spend a lot of time dwelling on my diabetes [here on JustAnotherCyclist.com]. It is not that I’m ashamed of my type 1 diabetes, or trying to hide it, but more that I mostly consider it just a part of my life. Thinking of it in that context I’m just not really compelled to post about it on web sites that I frequent, or write about it in my blog. However, every once in awhile something comes along that can potentially make my diabetes noteworthy. In this case, it is a change in the way I manage my diabetes that promises to make my cycling a whole lot better, safer and enjoyable. Well, two things actually.

After a fair amount of research I’ve decided to change from my current management routine of daily insulin injections and move to an insulin pump. To understand how this will effect cycling, I’ll need to give a little bit of background on diabetes and insulin. I’ll keep this very general – just enough information to help non-diabetics understand what’s going on here.

Basically, insulin is a hormone that allows the fuel you eat (food) to get into your cells. Yes – this is skipping over many actual details and steps in the process, but it is sufficient for our discussion. Your body (well, the body of a non-diabetic at least) releases insulin in response to – and in proportion to – the amount of food you eat. In addition, your liver releases a small, steady stream of sugars to fuel the general running and maintenance of your body even whenever you are not eating. As you might expect, your body also releases a small, steady stream of insulin in response to your liver’s small, steady stream of sugar. This background stream of insulin is called basal. It is in the management of my basal insulin that an insulin pump actually offers the biggest benefit.

I take shots of two different types of insulin a day currently. One – referred to as bolus – is taken in direct response to the amount of food I eat. However, since it is very impractical for me to take a whole stream of different shots each day to simulate basal insulin, I instead take two shots a day of dedicated basal insulin. This insulin, unlike my bolus shots, takes some time to “activate” – you can think of it as time-release insulin. I take a set amount in the morning, and a set amount at night, every day, day in and day out. This set amount has been adjusted through trial and error to match my liver’s steady supply of sugar mentioned above.

So far, so good. But there is another variable to throw in – exercise. Exercise actually allows your body to get the same amount of fuel (food, or more specifically glucose) into your cells with less insulin. It quite literally opens up more channels into your cells for sugars to get in and be burned as fuel. So, putting this together, I take a set amount of basal insulin each day that matches my baseline of sugars released by my liver. But then I go out for a nice long bike ride, and my system gets all revved up by the exercise. Suddenly, I’m burning through more glucose for the same amount of basal insulin I’ve taken in and eventually … I run out of available glucose in my blood stream. This is a condition known as insulin shock or, more properly, hypoglycemia. Definitely something to avoid.

An insulin pump alleviates this problem. The issue is that, currently, once I take my basal insulin shot I’m stuck with that amount of insulin until it wears off. However, an insulin pump more closly replicates what our bodies are supposed to do. Specifically, it releases small amounts of insulin slowly over time. That means that, when I go out for a ride, I can immediately adjust the rate of basal insulin released into my body. That’s a huge win – and significantly reduces the risk of hypoglycemia brought on by exercise.

That’s one of the two things I’m doing to help manage my diabetes that I’m hoping will have a direct positive effect on my cycling performance. The other thing – perhaps even more beneficial to my cycling specifically – is the utilization of a continuous glucose monitor. Currently, with traditional glucose monitoring, I have to prick my finger to get a drop of blood and put that blood on a strip that I’ve inserted into a glucose meter. That’s a lot of moving parts to manage, and damn near impossible when you are in the saddle. However, with a continuous glucose monitor, I’ll have a device attached directly to my skin that will sample my blood glucose levels (the amount of available sugar in my bloodstream) periodically and transmit that information to a small hand held device. With information available this frequently, the hand held device can track the trends of your blood glucose and and set alerts when my blood sugar is heading to levels too high (this causes fatigue and a general loss of power) or too low (danger!)

So, the scenarios where blood sugar levels are outside of norms will look like this by utilizing these two technologies:

Glucose Monitor alerts that blood sugar is getting low: Grab a gel from the jersey pocket and keep riding
Glucose Monitor alerts that blood sugar is getting high: Grab glucose monitor hand held unit out of jersey pocked and read value. Grab insulin pump controller out of jersey pocket and give an additional dose of insulin.

And without these devices? How do I deal with these currently?
Feel light headed and have no energy. Suspect blood sugar may be low: Stop riding, get off bike, pull out all the parts of the meter and check blood sugar. Grab gel and continue riding
Feel fatigued and listless. Is it high blood sugar, or just a hard effort: It is almost impossible for me to tell the difference between the two, so stop and check blood sugar with the meter. If it is high, pull the insulin out of the jersey and give myself a shot before climbing back on the bike.

As you can see, this is a huge leap forward. To use a cycling analogy, my current method of diabetes management in kinda like road racing before Mr. Campagnolo invented the derailleur. Back in those days, you had two different gears on the rear wheel, on on each side of the hub. You’d start the race on one. When you got to the bottom of a big climb (when you’d want a lower gear) you’d stop the bike, remove the back wheel and flip it over to make the smaller gear active. At the top of the climb – you guessed it, stop again and get into the bigger gear for the descent. That’s cycling the way I do it now. After Campagnolo’s derailleur, you keep riding right up that climb, changing gears by operating simple controls while you’re still in the saddle pedaling. That’s riding with an insulin pump and a continuous glucose monitor.

If anyone wants more information on this subject, don’t hesitate to get a hold of me, or contact your endocrinologist, diabetes educator or other medical professional.