Expertise and extensive experience have an important place in information about diabetes. But first impressions count too. The experts can miss key experiences when they aren’t coming fresh to a topic.
Today I am coming to you fresh from my initial experience with actually using a continuous glucose monitor. I started to wear it on Friday afternoon after two superb technicians from Medtronic MiniMed trained me for more than two hours in its use. Since then, the device tells me every five minutes what my blood glucose level is.
Continuous meters actually measure interstitial fluid, not blood glucose, but they run close together. Interstitial fluid lags about a quarter of an hour after rapid changes in blood glucose levels for two reasons. One is the body’s natural lag, and the other is the slight lag that measuring it introduces.
That’s why I didn’t throw away my old blood glucose meters. When the continuous meter reports that our levels are too low or too high, we need to double-check with a fingerstick. We also need to calibrate the continuous meter two to three times per day to get it to give us more and more accurate readings. However, in exchange for these two or three fingersticks, we get 288 blood sugar values per day.
The continuous glucose monitor that I’m using is the Guardian REAL-Time.
It wasn’t my only choice, but I picked it because it’s the most advanced one available. This is Medtronic MiniMed’s second generation device, replacing the Guardian RT (which confusingly stood for real time too). This new device also pairs with the company’s Paradigm pump, the world’s only system to integrate an insulin pump with real-time continuous glucose monitoring.
DexCom makes the other continuous choice, which I also like a lot. So much, in fact, that I have owned stock in that company since even before the Food and Drug Administration approved that monitor. But I don’t have any conflict of interest to disclose in writing about my new Medtronic MiniMed device.
Most people use continuous monitors to bring down their A1C level. But my A1C level is already where I want it to be. I want to reduce my glycemic variability, the measure of the quality of the A1C, as Dr. Irl Hirsch calls it.
I want to be able to see variations in my levels overnight, in the morning for the dawn phenomenon, after big meals, and before and after strenuous exercise. So yesterday, when I began to be able to see my levels at five-minute intervals, was an exciting day for me.
With the continuing help of Byetta, I am still eating small meals, so I haven’t yet noticed mealtime spikes. This weekend I am relaxing after four days of strenuous hikes in Rocky Mountain National Park last week, so I can’t report yet on the effects of exercise. I don’t seem to have the dawn phenomenon any more.
But I got some surprises. For the so-called “happy hour” yesterday before dinner I “rewarded” myself with a 1.5 ounce shot of my favorite single-malt Scotch whisky. I know that alcohol on an empty stomach reduces glucose levels, but I didn’t know by how much or when. It was a small amount, but I felt what I thought was being tipsy. In fact, it was probably feeling low.