Until recently, I was convinced that I — a type 1 diabetic — was insulin resistant. There were times when I could take 4-unit boluses on no food and not see any effect on my blood sugar for an hour afterwards. Breakfasts of 20 grams of carbs would take more than 5 units to cover. I began to suspect that I was developing insulin resistance, giving me a double dose of diabetes fun.
But I recently participated in a medical study that involved a hypoglycemia clamp, and it revealed something quite interesting. A hypoglycemia clamp means that a doctor manipulates your blood sugar levels so that you’re clamped in at a low level — in my case, around 60 mg/dl — to see how your body reacts. (In this study, they were looking to see whether or not I still had any ability to make glucagon, a hormone released by the pancreas that helps un-diabetic people avoid low blood sugars.) It means you spend a couple hours in a hospital bed with two IVs in your arm — one with a dextrose solution, and one with insulin. Considering that the insulin and sugar-water are both going directly into your vein, controlled by a computer, you’d think the doctor would be able to manipulate your levels with precision.
However, that wasn’t the case. As my doctor began to slowly increase the insulin drip, my blood sugar began to drop so fast that she had to rapidly up the dextrose drip so that I wouldn’t go too low. And then up it again. And again.
“Did you work out hard yesterday?” she asked me. “Because you’re really sensitive to the insulin.”
“No,” I said. In fact, I’d been in a different medical study the day before, so I had literally spent all day in a hospital bed, about as sedentary as I possibly could have been. “I haven’t worked out for two days.”
This continued for some time — a slight dose of insulin, followed by a recovery dose of dextrose. And then, when the study was over and I was allowed to eat lunch, I had to down three cups of apple juice — plus a dinner roll, pudding, and a slice of cheesecake (I did not pick this menu!) just to bring myself back up to normal.
It was truly bizarre — but also very validating. I now have proof that I am not actually insulin resistant. Far from it! Apparently once it’s actually in my blood, I suck it up like a sponge. The problem, it seems, is absorption: for some reason, it takes a really long time for the insulin from my pump to get into my blood stream. I’ve had this problem through multiple types of Minimed infusion sets (I’ve been on the Silhouette, the QuickSet and, most recently, the Mio). I’ve tried 6mm and 9mm cannulas. Neither is better. As for where I’m putting the site, my butt is definitely the worst (which is too bad, considering that it is essentially pristine diabetes wilderness, a vast expanse of potential sites) — but my stomach has problems, too. I’ve thought of using my pump for basals and then supplementing that with bolus injections, but that seems like a literal pain.
Instead I’ve been using Symlin, with relative success, in order to match up the curves of my food absorption with the speed of my insulin. I’ve also developed some odd habits, like taking breaks from work to do 100 jumping jacks, standing at the kitchen counter doing leg lifts on the side of my body where the pump is, or occasionally just using my fist to pound the area around the site (not out of anger, though I’m often pissed, but to try to increase circulation). As further proof that this is an absorption issue, I have had many, many afternoons where my blood sugar will stubbornly get stuck in the 180s for three hours, only to plummet (easily 100 points in 20 minutes) if I go to the gym. I guess I had a sense of what the issue is before I went through this study, but now I feel particularly validated that my original hypothesis was correct: it’s the absorption, stupid.
I’m wondering, does anyone else out there suffer from this syndrome? Any other suggestions of how to handle it? (Another one that works for me is to take a preemptive dose of Humalog about 15 to 30 minutes before I eat.) And any sense of when there might be a new version of fast-acting insulin available? I’ve heard rumors that there are some in the pipeline, and — as is true with so many aspects of diabetes care — I can’t wait.