Wednesday, October 28, 2009

Blood Sugar Wrangling

For those who don't live with diabetes, here are some reminders:
basal rate = background insulin, usually fast-acting, delivered 24/7 by an insulin pump
bolus = equivalent of an injection of insulin, usually rapid-acting
CGM = continuous glucose monitor, which gives glucose readings every 1 to 5 minutes
BG = blood glucose, measured by a BG meter; aka "blood sugar." Normal is 70 to ~120 depending on various conditions. BG is affected by insulin concentration, stress, exercise, food, illness,...
insulin = hormone that facilitates movement of BG from blood to cells; fast-acting insulin starts working fairly quickly, peaks in about an hour or so, and sticks around for 3-4+ hours (for me). Exercise makes insulin much, much more potent.

The other night, I woke up around 1 AM feeling weak and hungry, as if I had low blood sugar. I checked and it was okay at 100. Not sure if my BG was rising or falling, since I am not, sadly, using a CGM right now, I ate half of a gel--about 10-15 g carbs--and went back to sleep. When I checked again before starting a morning swim, I was startled to see 279 on the meter. If anything, I have been waking up low in the morning recently since I significantly increased my basal rates. I was about to hop in the pool and figured leaving my basal rate at 100%, instead of reducing by 20-30%, plus skipping a pre-exercise snack, would help knock it down. Although I might typically give a little insulin to get things started, I decided to forgo it because of my elevated basal rate. I started my swim with a big set of 50's and felt thirsty and lethargic. I kept going, realizing that some days are better than others for a variety of reasons; still, I was having to work really hard to make intervals that were manageable the week before. After 45 minutes, I checked my BG, which had risen to a sticky 316. Ugh! No wonder I felt horrible. I gave a 1.2-unit bolus, drank some more water, and got back in the pool. A little disconcerted, I checked again about 20 minutes later and saw that I had already fallen to 262, and following my swim I had settled down to 122. There were many moments during the first half of this swim where I wanted to call it a day. While I am obviously a big fan of exercise, I do it for health benefits and for my enjoyment; it is not required to be an act of heroics! But sometimes, it sort of feels that way. Once I could see that my blood sugar was falling, I felt comfortable from past experience that things would improve. Throughout the day, I still felt off, and wonder if my probable prolonged overnight high BG had taken a toll.

My blood sugars were pretty oscillatory for the day and I had a late lunch/snack around 4 PM, requiring about 6 units of insulin, which is a lot considering my daily insulin is anywhere from 20 to 35 units. I was supposed to run after work, but had not been looking forward to it during the day. With my IT band troubles as of late, I haven't been able to really enjoy running, with each run ending in pain and frustration. Maybe I subconsciously ate late so I could use a massive bolus-on-board as an excuse? It's possible. For some reason, though, taking a lot of insulin made me feel a little better and I started to think that maybe I would run after all. So, about 45 minutes before I started running, I knocked my basal rate down by 90%, meaning I was basically taking little to no insulin. I didn't really think this would work, but had plenty of back-up GU handy. At 6:30, I started my run; I decided to run on the track in case I had to bail early. My BG was at about 120 and I decided I would just run and see how it fared. I just didn't want to eat more calories if I could help it. About 30 minutes into it, I had that sudden realization, "I'm low." I was at 74 and ate one gel and kept going. My blood sugar came back up nicely and I was able to finish my 50-minute run without any BG or IT band catastrophes.

In retrospect, it would have worked better to take a little insulin before my swim, and check partway through. If I needed to eat at that point, I could have. Also, during my run, I felt like it was likely that I would drop, so it might have been better to eat before I got started, rather than waiting until I was low. (Well, in the first place, it would have been better to not take 6 units of insulin that close to exercise.) In both cases, I was motivated by trying to avoid eating extra calories. I had to eat the calories anyway for the run, and getting my BG down sooner during my swim would have led to a more productive, healthier workout. And I was definitely hungry in the pool, so being able to eat a gel might have helped me swim stronger.

In the end, I was happy that I was able to get through both workouts, although the mental struggle in getting through them (and even starting them) was tough. I do love exercise, but that doesn't mean I love every workout. Anyway, Ironman Arizona is coming up quickly and at this point, each workout is key and will make a difference in how I feel race day. I am hoping that a little pain now will make race day a little less painful; I'd like to keep my focus on the wonderful experience of racing with my Triabetes team and watching out for my Triabuddy Elisa and other friends and family along the course!

Note: We're still short of our fundraising goal for the Triabetes documentary. Please click on the widget to the right or go here to donate a few bucks if you can. You can donate anonymously if you want by putting in an anonymous name on the first page. Note that Crazy Sea Lion has done just that.