Decreasing Sugars

I was happy last week because my spot-sugar was a “normal” (i.e. non-diabetic) value, about 5½ mmol/l (100 mg/dl). (After the last post, I’m going to try to quote both units.) But I observed at the time that a one-off value is just that, and not particularly important except in the context of all my other values.

Today, my average sugar – all the readings over the last month – dipped below 9 mmol/l (160 mg/dl), for the first time since I started calculating averages. This is not a particularly significant number in diabetes terms, so again this is mainly me playing with numbers rather than anything significant, but nice to see my average getting lower. I note once again that it takes two insulin injections per day to get to this level.

I also measure a statistical property called the standard deviation. It’s quite straightforward to calculate, but not trivial. An application like Excel will calculate it for you. It is basically a measure of how much your sugar varies with each measurement. Obviously, if you take one measurement and you’re at “really low”, and the next measurement at “really high”, then you have an average which probably isn’t very remarkable, but it’ll hide these extreme values.

So possibly of a greater cause for note is that I’ve got this variance down to about 1.4 mmol/l (25 mg/dl). So my average is 8.9 ± 1.4 mmol/l (160 ± 25 mg/dl). In a healthy person, your pancreas produces sufficient insulin that your body’s sugar is pretty constant, so the smaller the it varies, the better. For me, whose pancreas doesn’t produce enough insulin, 1.4 represents the smallest variance since I started taking measurements back in 2016. Because I take readings every day, I end up with 30 or so per month, so typically the standard deviation will only change by a tiny fraction per day, so it takes a while to notice much difference in the numbers.

International Readers

Side-by-side from my blogging, I am developing a Diabetes Management application. There are basically two different units in use (for glucometer readings) worldwide. This is not exhaustive but the UK, Australia, China use the units mmol/l. Most of the rest of the world uses the units mg/dl, including mainland Europe and the USA.

I’m developing this app, which I want to support both units, so I’ve read up on both units. But I got to thinking, and my wife confirmed this, that many people, even health professionals, are intimate with the one unit but know nothing about the other.

Starting from basics, both units are used to measure the same thing. This is like miles and kilometers. HBA1C is measuring something different. So there is a relationship between the two units, which is basically:

1 mmol/l = 18 mg/dl
So, to give an example, I’ve talked about blood sugars of 15 mmol/l in the past (I’m almost half that now!) – this is 270 mg / dl. My current average is 8.9 ± 1.4 mmol/l – I might say more about that in a later post – which is 160 ± 25 mg/dl. So clearly, above that of a non-diabetic, but getting better. As I’m starting to work with this new unit, I’m finding it quite convenient, and in fact I’ve changed my app to store the numbers, internally, as mg/dl. although, of course, it is just a number. Each number in the database carries with it some crazy-silly precision, so 10 or 200 doesn’t make any difference to it.