A Maths Test, a White Witch and the Dark Art of Diabetes

Last week I attended a lecture about diabetes and the use of motivational interviewing.  Interesting as it was, I have remembered one key thing that the lecturer said – that people with type 1 diabetes need to understand maths to GCSE level C, as a minimum, in order to manage their condition well.  I knew this of course and I also know that I struggle sometimes, despite my competence at maths; when you are tired and it’s late, working out ratios and residual insulin vs your carbohydrate intake can be a challenge.

Maths test:

Can you work out, for example, how much the total carbohydrate value is for these sandwiches?  There was, by the way, no total weight on the pack to help…..



The results from the continuous glucose monitor or CGM

Last time I blogged about my diabetes I told the story of my sensor and how challenging I had found it.  I can report that the second time it was a success!  My DSN inserted the sensor and I managed to get 12 good days readings.  I do think it must be difficult to manage some of the data on your own if you are not inclined to maths and stats.  The graphs are complex and not for the faint hearted – I think they are complicated especially when there are multiple-factors that could affect the results.  An example of a graph of my results is shown below: (pretty isn’t it 🙂 ). This was the second set of 6 days and are terrible!  They are all over the place but the adjustments I have been able to make as a result have made a real difference.  The continuous glucose monitor hopefully will have helped me to regain a better level of control.  I had accidentally disconnected the pump one night and another I just couldn’t get my blood glucose to go down.



Since I’ve been thinking more about my diabetes I have come to realise that its a lot more complicated than I lead people to believe.  As someone once said to me ‘diabetes is a dark art’.

Its not just as straightforward as taking insulin to cover the food you eat, even if that’s what many nurses learn.  Well, of course at the very simplest level it is, but there are so many other factors to think about.

Some extra factors to consider….

I found out from my sensor that I am more insulin resistant in the morning than the evening so need a different carbohydrate to insulin ratio between 6 am and 12 pm, so not only do you have to be good at sums you have to be able to tell the time too.  And of course there are some foods that just don’t seem to work out; for me pastry and fish and chips just guarantee a hike in blood glucose no matter what I seem to do.  Other people complain about pizza or pasta which I seem to manage fine – its so individual and therefore there are few hard and fast rules and its a lot of personal learning.

I also discovered that I was hypoing at night and getting a resultant rise, which meant I was sometimes waking with an unexplained (till now) high blood glucose.  I also have some dawn phenomena, a rise in blood glucose caused by the normal production and release of growth hormone which results in a rise in blood glucose in the mornings.  Its common but means that the basal (base amount of insulin given continuously via pump) has to be adjusted to different rates over the day.  I currently have a pattern that delivers 5 different amounts in the day.  Confused yet?

If I am doing something stressful at work then, counter-intuitively (you expect a low blood glucose) I need to take extra insulin.  If I am running a workshop all day for example I would increase my basal rate by 25% overall.  I’m doing a big presentation this week so I will need to test quite a bit and probably adjust to take account of a probably high otherwise I will feel poorly.

There are so many things to think about.  It really is, as I’ve said before, very complicated and no one person with type 1 diabetes is completely like another.  I don’t think about it all the time but neither can you have a day off.  So, I’ve decided that I am really a white witch who struggles to manage the dark art of diabetes. I quite fancy myself as the white witch from Narnia, slaying the dark monster diabetes.

The white witch from Narnia


Did you get the carb value right?  Its 46.6 gm CHO

10 thoughts on “A Maths Test, a White Witch and the Dark Art of Diabetes

  1. Ah the Dark Art of Diabetes indeed! Great blog as always Anne. Well done on finally getting to grips with the sensor-i knew you would. Your graph looks beautiful 😉 With regards to carb values on food, I wish we were a bit more like the States, they have carbs on everything. On the positive side we play very competitive ‘guess the carbs’ games in our family! x

  2. I really enjoyed your post Annie. We make it seem easy but there are many variables and no single formula that works every time. My maths was my weakest subject but then I got late onset T1 Diabetes AND I work in investments. I also recognise that nutrional information in the pic, and let’s just a little bit more (information) would help in this instance!

    I loved looking at your graphs, a CGM reveals all the sneaky hidden stuff that goes on inside us. I like graphical representation of data probably because I look at stock markets all day.

    P.s I guessed 40g carb but in this early stage of my Diabetes and still on a half unit insulin pen, I would have needed a correction afterwards.

  3. I made this observation about numeracy skills many years ago to a very influential prof of medicine – from their vantage point of high achievement they really don’t see the issues – great words and work Anne.

  4. Good blog about the ‘micromanagement’ requirements of Diabetes. I kinda go on how I physically feel as to how my blood sugar is. It feels very much mixed messages from the powers that be – NICE say T2’s non insulin dependent not to test but now there are sensors so you can see what you are doing minute by minute if you are insulin dependent.

    I can see if you are not numerate or haven’t had the *right* dietary information / education or even just have a busy stressful life, how this requirement for micromanagement for *good* control can be an extra burden. Any good apps out there to help with this problem?

  5. “Its not just as straightforward as taking insulin to cover the food you eat” – how true! That is most probably the hardest thing to explain to people – even HCPs. Time of day, stress levels, activity levels, illness, weather (maybe!) etc are all factors to consider and the joys of weighing with your eyes is always problematical. Asking someone who thinks it’s easy to look at their dinner plate and accurately calculate the amount of carbohydrate is always an interesting conversation. I LOVE the graphs – so jealous (#qself) Maybe when I get see my new consultant in January I might get the opportunity – yes I have the letter 🙂 Great blog as always, thank you!

  6. Great blog!

    I’ve also found that other factors affect my dosing calculations such as: other medications I take, temperature, showering, stress levels, intercurrent illness, time of the month and how active I’ve been or plan to be that day. These are just the factors that I’m aware of – I believe there are other variables that I’m not aware of.

    Sadly I don’t think this is something that doctors and nurses really understand with their simplistic carb to insulin ratios. The doctors and nurses I encounter seem to believe that patients take the same dose of insulin every day at the same time each day.

  7. Thank you!
    I know – its only the specialist nurses who really seem to understand how complicated it is, especially when you are trying to lead a normal life. My biggest issue is when I’m very tired – I just can’t summon up the energy to be accurate and end up guessing – as you not that sometimes can be a disaster!

  8. Hi Annie, great post! I’ve found it today because I’m trying to track down the original source for the GCSE-level maths point, which I heard from a friend the other day. Having had type 1 for 18 years I’m sure it’s true! I would just like to give credit in a piece I’m working on. Can you tell me the name of the lecturer on your course? Thanks!

  9. Im not on a course but it was Angus Forbes at KCL.
    Did you search maths literacy and type 1 diabetes as I found quite a few bits on google scholar although they look predominently american or canadian.
    Good luck!

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