Practicing What I Preach
I put the Dexcom on one week ago and love it! It’s great for those times when you’re fairly sure you know what your blood sugar is doing so testing would feel superfluous, but you want some confirmation. When I was out for a run this morning, I saw that my blood sugar was dropping, but not too quickly, so I knew about how far/long I could run before going low.
But, I’ve fallen into the very trap I wrote about last week – overreacting to the Dexcom data and generally not using the information effectively. Case in point occurred on our drive to Disneyland on Sunday morning. I’d baked paleo Almond Scones to have with coffee on our drive. They had chocolate chips in them and just a little maple syrup, but all in all, not too many carbohydrates. I bolused a couple units of insulin, figuring that I’d be sedentary in the car for about 90 minutes, plus the coffee had creamer in it. My blood sugar was around 120 mg/dl before eating (after a small bolus for dawn phenomenon). About 20-30 minutes after eating, I saw the graph on the Dexcom start to climb. At one point it read 184 mg/dl with double arrows pointing up. I tested and got a result of 212 mg/dl.
My thoughts instantly went to, “Oh, I didn’t give myself enough insulin!” “There must be more carbs in these than I thought??” So, I promptly bolused a little over 2 units of insulin to correct the high blood sugar and went back to enjoying the drive with my very excited kids.
Any guesses what happened next? Well, I glanced at the Dexcom only about 10 minutes after the correction to see that the arrow was now level and the graph peak was starting to turn around. Great! I knew right then that I’d done exactly what I said I wouldn’t do with the CGM this time around: overreacted and unnecessarily corrected! A half hour later my blood sugar was in the 150 mg/dl range on the Dexcom, but actually 113 mg/dl on my meter. I was about to hike all over Disneyland and had to consume a bunch of carbohydrates to keep my blood sugar up over the next hour. So frustrating! Here I’d already had a ton of calories in my low carb scones and then I had to eat more to feed the insulin. Ugh!
I realized my error was simply forgetting that the Dexcom lagged behind real time. I think I’m having some psychological issue with the arrows! I interpret them as meaning my blood sugar is currently rising that quickly when it’s actually telling me it was rising or falling at that rate. Which, in this case would make sense with the high blood sugar result on my meter. Since I’d already given myself enough insulin to bring my blood sugar back into range, I didn’t need a correction bolus. I HAVE to practice patience and perhaps institute some kind of rule about correction boluses- something like no extra insulin doses until 1.5 or 2 hours after a meal bolus.
Other CGMS wearers: how to you deal with this issue?