According to the "magic formulas" which are meant to give you roughly a 50:50 ratio between basal and bolus, I should have a basal rate of roughly 1.5/hour. Seems high, right? that's because it is too high. I've said multiple times that I'm skeptical of this ratio.. not the least of which is that any one with half a brain would have said that ratio is 1:1, but whoever wrote this ratio down obviously wanted to drill home the 50% aspect of it. Gah.

Anyway, we learn by making mistakes, so I decided to put this ratio to the test.. if I'm using 100 units of insulin a day, then surely I need 1.5 units an hour (according to the formula). So I set the basal rate to this and 2 hours later, I have myself a hypo. I went from 134mg/dl down to 48mg/dl in the space of two hours. Clearly 1.5/hour is wrong.

Why is it wrong? Well, pretty much for the reasons I've said multiple times on my blog so far. The amount of carbohydrates I eat from day to day drastically changes based on my diet. If I use 60 units a day, the formula says my basal rate is meant to be 1.0/H and if I use 80 units a day, 1.33/H and 100 units a day, 1.66/H.

Do you know what 20 units of insulin would buy me using my old calculations? a rough guestimate of about 100 grams of carbs, which is, say, 2.5 slices of pizza. My meal regime can vary that much, that easily.

So, if we learn from our mistakes, then I must make the mistakes myself - I've been saying for a while now that I've been following the play book and seeing where it takes me. I'm unconvinced that the numbers provided to me by the diabetes educator are right.. so it's time to do this experiment my way.

I'll lay it out for you and tell you the results, since I'll be reporting to my blog, not the diabetes educator on this little trip:

Starting with a basal rate of 1 unit an hour, I'll take a measurement in the morning when I wake up and continue to fast and measure the rate of change every hour until I'm too hungry and I have to eat. This should give me 3..4 hours of variance. I'll probably eat at that point and then ignore any results for the next 4 hours - whether or not my bgl is high, I'll then resume the fast for another 3..4 hours worth of results at a new basal rate of 1.1 unit an hour if my bgl was running high in the first test.

I'll do no correction at this point, the 0.1/unit an hour will give me a delta rate of change and from that I'll compute a guestimate basal rate, set it and see how the night goes. Note that this rate of change also gives me my insulin sensitivity, so I'll adjust my correction rate at the same time and give myself a correction, assuming my bgl is running on the high side from brunchfast.

The next day, I'll repeat the fast and hopefully my bgl will remain steady from the night before and through the morning. If so, the basal rate will have been set and I'll move on to testing the insulin sensitivity as set for the correction factor. I'll give myself one unit of insulin and see how my bgl changes over the next 4..5 hours without food (fasting again). This will tell me my sensitivity to one unit of insulin.

Once that is set, I'll be able to go without food and stay stable and correct when the food is wrong. Finally, once these two values are correct, I'll hone in on the carbohydrate ratio to try and perfect that - now this is where things get a little dicy. The carbohydrate wizard has a carb ratio of insulin:carb. It's in whole units, so this is a rather coarse setting, which might explain why they tend to bump up the basal toward this 1:1 ratio, however, I have no interest in hypoing if I don't eat. We'll see how I go.

It's entirely possible that once all this is done my numbers will even out to a nice 1:1 ratio, but if that is a by-product of computing these values the way I describe above, then so be it - however taking the average of units used per day and pumping them through these 1500 and 1700 formulas has not gotten me close to my target so far, so I do not expect this ratio to bare out.

We will see.