We all know the likely culprits of lows: over-shooting a carb count and over-bolusing is a big one. Intense exercise or extended exercise is another. Sometimes being ill can cause wide swings in BGs which we over-correct and then bottom out from, especially if you can’t keep anything down.
But there’s one major predictor of lows that I often forget about: having a previous low in the past 24 hours is a risk factor for another low. Strange but true, lows beget lows. If you wake up dipping low, it’s likely you’ll have another one later in the day. My CDE and I have talked extensively about this. He will take his yellow highlighter and prove the point in my log book by marking the two, sometimes three or four lows I often get in the same day after a long stretch without one.
It’s a sneaky risk factor, because you’d think once you level out that you should be back to “normal” (whatever the heck “normal” is defined as when you have diabetes). But having one low makes you susceptible to another one later in the day. Its almost as if a low BG increases sensitivity to insulin, or decreases sensitivity to carbs.
I’m actually unsure of the physiology of why this happens, and if anyone knows please share – I’d love to know more. But in the meantime it’s all about being more cognizant of lows when they happen. It’s a factor I don’t often take in to account by the time the next bolus rolls around. I test, think about what I’m eating, if I’ve worked out, but rarely do I reflect on whether I’ve had a low in the past 24 hours and factor that in to my bolus.
It’s also another good reason to treat lows with only enough carbs to bring you back up safely. When we overdo the correction, we often end up high, bolusing, then crashing out again. And there’s nothing worse than being on that high-low sea-saw.
Actually there is something worse: four lows in one day. Its just like the old saying says: “where there’s one low….there’s another on the way later that day”…or something like that