Posted by on Monday 22 February 2010

Some units are more equal than others

All units of insulin are equal, you would think. But it seems some are more equal than others.

A week or so ago I had a very odd hypo. In fact it was that experience and some of the conversations we had about it afterwards that were the catalyst for us as a family to begin this blog. A place where we could write about our own experience of living with diabetes. Look at it from different angles, poke it with a stick, turn it over and over. The very act of writing these things down means you have to think about them quite carefully. To consider how you feel. To wonder what they mean. This in itself probably makes the writing worthwhile. Not in some maudlin, self-pitying, navel gazing way, but because when you've lived with a condition for a decade or two there is a tendency to begin to ignore it. To stop really thinking about it in any front-of-mind way. It's just there, the elephant in the room, squashing furniture, generally making a mess and getting in the way but largely ignored.

So even if you weren't reading this, it would still have been worth my writing it. Well not this bit actually, this is just the preamble. But the next bit definitely. In fact probably best if you just skip forward to the next paragraph and save us both some time. Here is an amazing thought though. A week or so ago I had an odd experience with a condition that I've been living with for about 20 years. And now, just a few days later you can read about that even if you live on the other side of the world. And if you have shared an experience that you read here, you can make a comment and you and I will know that someone else has been there. That it's not just us.

When the dust had settled on the hypo of the weekend before last we wondered why some of the symptoms of low blood sugar had extended for hours after normal and even quite high blood sugars had been restored. Why it had taken almost until the evening for me to fully 'get my words back'. It didn't help that when asked whether he thought this might ever happen again the doctor gave a pretty unequivocal, "Yes". It seems possible (though we are only guessing really) that a slight miscalculation of the size of jacket potato the night before might have led to a quite extended period of hypoglycaemia overnight. I woke with a start from a dream at one point which might have been my body trying to kick me back into consciousness to get something sugary, though my hypo-addled brain made up a convincing story about Derren Brown, subliminal mind control, advertising, Apple products and Twitter(!) and I just turned over. Maybe the length of period I spent with low blood sugars meant that part of my brain got stuck in hypo mode?

Overnight hypos are never a good thing. I'm lucky in that they are a far rarer thing for me now than they have been in the past, and they were never more than a few times a year even then. Nevertheless we have been left with a desire to try to tighten control again. If I am honest my focus has always been on keeping my sugar levels down rather than avoiding an occasional low blood sugar. Avoiding long-term complications and accepting hypos as a price to be paid for aiming at the tiny target range. Now I felt like I was being pulled in the opposite direction. Wanting to avoid having a hypo like that ever again.

I've been on Lantus glargine, a peakless basal insulin for a few years now. Peakless has always made a lot of sense to me in the context of a basal-bolus system and I certainly believe that it has helped cut out some night time hypos associated with a long-acting insulin which has a peak of activity. Of course peakless doesn't really mean peakless, it's just that the peak of activity for glargines is much less marked and the activity profile is far more level than other long-acting insulins. The shift to glargine involved the inevitable period of experimentation in terms of getting the new levels right. After the switch I found I was usually high first thing in the morning. I increased my night time dose from 10 units in increments of two in an attempt to get things back in line again. Initially I settled on 16 units, but all that extra insulin sloshing around made hypos during the day more common and after some more weeks (and quite a bit of chocolate) I settled on 14 units of glargine. Any diabetics reading will not be surprised to know that it wasn't quite as simple as that though... in that classic altering-your-doses-Kerplunk way, there was another unexpected consequence. Since beginning on a basal-bolus pen-injection system I had always taken my short acting injections before eating. Since I began using NovoRapid this has been immediately as I started eating. Now I was finding that if I injected before eating (especially if my levels were in the 4-6 target range) I would end up going low just after the end of the meal. It was almost as if the short-acting insulin, on top of the glargine was pushing sugars out of my bloodstream so rapidly that my digestive system couldn't keep up. The obvious answer was to give my digestive sytem a bit of a head start and wait till after the meal to inject. Obvious, yes; but after fifteen years of injecting before a meal I can't tell you how hard it was to try to remember the injection once it was all over and time for the washing up. I forgot to inject ridiculouosly often. Several times I even double-dosed forgetting that I had remembered. Not good.

After perhaps a year I spoke to my doctor about the difficulty and wondered whether there might be a different, slightly less aggressive short acting insulin I could switch to. Her advice was that it was more likely to be the higher level of background insulin and that I would be better reducing my night-time dose of Lantus. I tried it for a day or so, but immediately my morning sugar levels rose up and I went back to 14 units. Better the devil I knew.

So here I was again looking at my doses and thinking, maybe the 14 units of glargine was the reason for the hypo from hell. Maybe I did need to reduce that dose after all. It was time to give it a bit more of a thorough test. I tried it all last week. It was very interesting, and really quite confusing.

Two units of Lantus glargine make an impossibly big difference.

Over the last year or two it has not been uncommon for me to wake up with slightly low blood sugar. Something in the 3.5-3.9 range. Once or twice a week sometimes. A little fun-size bar with my morning coffee and I'm quickly back to normal. A few times a year I've woken up a little lower still and my brain function has started to fall to pieces. Repetitive action, confusion, talking nonsense and general family hilarity all round. So from that, I reduce my glargine night-time dose by 2 units and wake every morning with sugar levels pushing into the teens.

But it didn't end there.

Of all my meals, breakfast must be my most consistent in terms of matching units of short-acting insulin with carbohydrate. More often than not it's a bowl of high fibre cereal weighed on a set of scales, with skimmed milk and low fat natural yoghurt. Dietetically I'm on my best behaviour. But suddenly the usual rules did not apply. I would over-jab and under-eat and two hours later rather than finding my earlier high sugar levels corrected things would be just as bad or even slightly worse. I would find myself adding an extra four units of NovoRapid to bring my sugar levels down in between breakfast and lunch. Four units. Four.

Again after lunch some perfectly guessable bread/sandwich/piece of fruit carbs when matched with their usual dose of NovoRapid would result in significantly higher blood sugars than I would expect. Another four extra units of NovoRapid to try to keep things under control.

Well at least you managed to stave off the hypos though you say. Nope. Not a bit of it. Possibly partly because I was struggling to stem the ever-rising tide of blood sugars with usual meal/dose calculations no longer seeming to apply. Extra correction doses seemed to work OK as long as I was sat at my desk, but any kind of physical activity - even just a short walk to get some milk - was enough to drop me into needing something sugary. Thank goodness I didn't go to the gym that week.

I don't know whether this extremely fine balance between short and long-acting doses is familiar to anyone else but I find it very odd indeed. I can't explain how the reduction of just two units on one type of insulin can have such a huge effect on requirements for other dose-and-meal combinations, adding in an extra 8-12 units over the course of a day. Previously I had only experimented it for a day or so before reverting to what I knew, but to see the same things happening over the course of a whole week convinced me that it was not just a matter of miscalculation or bad guesswork. The whole balance of how many units to how much carbohydrate with how much activity had completely shifted. I may have had a few fewer hypos, but my overall control was so much worse that I felt I couldn't continue.

So for now I'm back to square one. The usual rules are applying again, and I'm just testing a whole lot more often. I might go back to having supper again. A piece of fruit just before bed that used to stave off the overnight peak activity of Insulatard in the years before the switch to glargine and the whole what-to-do-about-waking-up-high conundrum.

Your guess is very nearly as good as mine.

Update: Curiouser and curiouser...


  1. Hello Mike,

    I am also type 1 diabetic and am also on glargine and novorapid so I read your post with interest.

    My first thought when reading was "adjust your glargine by 1 unit instead of 2". I do that with a new Lantus pen called Solostar which allows you to do that.

    I feel your pain with the Lantus though. I'm also at 14 units right now (how ironic!) and I don't always get good results, but my HA1C is 6.7 so I'll have to say it's doing okay.

    Of interest to both of us: Novo Nordisk are currently running trials for a new glargine, designed to be (in their view) even better than Lantus. I was offered to participate in a trial of this new insulin if I contined to feel annoyed with Lantus. This is great news I find.

    I feel I could say much more, but I have gone on and on! I do love to talk diabetes! Good luck and health to you.

  2. Thanks for your comment.

    Yes I would have tried that, but I'm forced to use the dreadful 'Autopen 24' which, aside from being awkward to use, hard to read and not allowing you to alter a dose if you misdial it, only allows doses in increments of 2 units.

    You may have read my follow-up post of a few days later... well I've arranged an appointment with my GP in the next week or so to talk through options/regime changes so I'll post again after that.

  3. Mike, I don't know if you're still using the Autopen 24, but I've recently switched to the Sanofi Aventis ClikStar, which has single units as I had similar problems....

  4. Hi Clara

    When I went for my appointment I switched to the green Autopen 24 which, while still terrible, at least gives 1u increments. VERY useful as since posting this I've discovered that my basal requirements change up and down by a unit quite often.