Diabetes and lifestyle with the FreeStyle Libre

In the comments to my review of the Android LibreLink app, I pointed out to Daniel that (much as I don’t particularly like the “blogger” label), I’m not a diabetes blogger, I’m a tech blogger who suffer from diabetes, and for that reason most of the stuff I posted about it has to do with the technical sides (after all the original set of posts were titled “Diabetes control and its tech”.)

I have, though, to excuse myself for once and write a little bit about lifestyle, but probably not from the same point of view that other bloggers might take in their writing, mostly due to style and interest. But I did say I would talk a little more to how the FreeStyle Libre changed my behaviour since I started using it in January this year (some ten months and something sooner than it was available in the country I live in.)

The Libre, unlike other CGM solutions, is not a real-time solution: it uses interstitial fluids for measurement, and because of that they provide warnings about time-delay, and quick changes in blood sugar; they don’t provide that much specifics, but I noticed something along the lines of 20 minutes delay after eating for the blood sugar to push back up, and what to me looks like “smoothing” of the graph, so that sudden changes in blood sugar are not noticeable. This is also due to the sampling rate (one reading once 15 minutes.)

So while it is not a perfect solution, particularly if you’re relying on it for taking fast insulin, it makes for a good learning experience. By looking at a graph after the fact, while the damage is already done, you can at least know what to repeat and what to avoid. If you want to be buzzword-y you can define it as human deep learning.

What I found is nothing particularly new or exciting, particularly for experts of diabetes, but it did help me understanding to what extend blood sugar can sway based on activity. I wanted to at least talk about some of the experiences I had over the past few months, just for sharing. It might or might not be of help to others, but at least I can show what kind of useful lessons can be learnt with solutions like the Libre.

Some months ago I went to IKEA to buy some furniture for my apartment in Dublin, namely a cupboard, and a new sofa (the one I had before turned out to be moldy from before I moved in, so I asked my landlords to please allow me to change it.) I received them on a Saturday very early (for me) morning: 8am. I had to wake up at 7.25am and have breakfast, I had a significant breakfast, which as usual involves lots of coffee. The delivery men brought the boxes inside and took the old sofa out, but the rest was up to me. I started with the sofa, and by 11am I had it done. I had to stop midway through to eat a packet of chocolate biscuits because I felt a bit dizzy and I found that I was going low on sugar quite quickly, even though it did go over the 10 mmol/l limit after breakfast. I had another “heavy” lunch (as in, more than double my usual amount of pasta) because I was still on the lower-side of the range, and I had one more piece of furniture to build. I had to stop by 2pm again to eat some ice-cream because I was below the 4mmol/l already. Over the course of the next two days, no matter how much I’d eat: pasta, ice-cream and biscuits, I didn’t go over 9 mmol/l at all.

What does that tell me? It’s clearly not bollocks when they say that physical activity helps a lot with diabetes; assembling IKEA furniture is clearly not a sport, but it worked effectively the same way. I’m still a lazy bum and have not done any sports, part of it because I feel horribly out of place in a gym, though I did enjoy bouldering with colleagues before, I should try that again. To be honest, this was not entirely new to me either; not only I did notice that even the WiiFit exercises used to help me lower my blood sugar much quicker, back in Italy when I was not on insulin nor under a solution like the Libre, but when a couple of years ago I ended up taking the 23andMe test, one of their reports had interesting information that was actually relevant to me:

Insulin sensitivity response to exercise: Exercise is associated with a 2% improvement in insulin sensitivity, on average.

Teran-Garcia M et al. (2005) . “Hepatic lipase gene variant -514C>T is associated with lipoprotein and insulin sensitivity response to regular exercise: the HERITAGE Family Study.” Diabetes 54(7):2251-5.

Improvement in glucose tolerance with regular exercise: Glucose tolerance improved with regular exercise.

Ruchat SM et al. (2010) . “Improvements in glucose homeostasis in response to regular exercise are influenced by the PPARG Pro12Ala variant: results from the HERITAGE Family Study.” Diabetologia 53(4):679-89.

Correlation does not imply causation, but these information correlate with my personal anecdotes, take it with as much salt as you want.

Speaking of correlation, and (as you’ll see) of 23andMe. I’m sure we all have wondered at some point if the drugs prescribed by our doctors actually help, or if they rely almost exclusively on placebo effect. Well, I unwittingly went through that experiment, by forgetting my meds a couple of times — anybody who’s on any kind of daily meds would tell you that even though it’s bad, it’s not always easy or obvious to keep your meds routine straight and never forget any, I can tell you that while travelling across timezones, it’s even harder. Since I’m on both insulin detemir and gliclazide I have at some point forgot one, the other, or (much more rarely) both. And I did find something interesting: I can much more easily notice by the graph the days in which I forgot the gliclazide than those in which I missed insulin. Missing insulin looks a lot like eating too much, particularly for breakfast. Missing gliclazide looks like the Y axis got transposed so the values read at least +3 overall, if not more. You can imagine that after I did make a mental note of that I paid much more attention to the pills than the injection, in the morning (it’s easy to do the opposite, since the injection requires more minding.)

As I said, this was also notable in the 23andMe report:

Sulfonylurea Metabolism: Somewhat reduced ability to clear sulfonylurea drugs from the body.

(This one has way too many references to easily cite them all, but it looks legit, my doctor was also interested to learn more about 23andMe after I sent him the printed report about this one.)

Staying with the list of don’ts, let me tell you about dessert. It would be easy to just say that diabetics should stay away from desserts at all time, but that is not true, as anybody with a bit of direct or indirect experience on the matter would know. Among other things, even though my friend the dietician gets upset when I do that, I have explicitly limited to a light lunch to be able to get a tasty and sugary dessert. This is not good of course and so I really do that rarely.

On the other hand, even with a normal lunch or dinner, I have started finding which configurations of meal could allow me to have a dessert and which does not. Turns out, what you ear is far from the only variable either. When you eat is also a factor, so for the same dessert I can have it for lunch, as long as I do my half hour walk home, but if I have it for dinner, even though I walk home, it spikes my blood sugar so high that I was seriously worried about my life.

All in all, the lessons I can learn from this device are still plenty, but it also means I am learning to look after myself a lot more than I was doing before, with significant less effort. It makes me happy, so I’ll be happy to continue paying for this if HSE is not to cover them (which is still unclear to me.)