Wednesday 5 May 2010


So I have now reached the half way mark towards the end of my CGM sensor trial, and man am I torn!

When I started the trial, I had hoped that I would be able to wear the sensor for longer than the recommended 6 days, because getting even 12 days out of one sensor would halve the potential cost, meaning it would be much more manageable. Bearing in mind that it can cost in the region of £180 per month to use CGM, which is a fair old price by any stretch of the imagination, just those extra few days could be a deal breaker for me!

As expected, my pump cried out one of the many baffling alarms yesterday to let me know that my sensor had expired. Truth be told, there are so many alarms on my pump, I usually NEVER know what I'm being warned about without looking at the pump. This one, I had been expecting.

I swatted up all about CGM before the trial and already knew that many people have managed to trick the pump into thinking the old sensor is in fact a new one. So as long as the enzymes in the sensor which communicate with my glucose are still there, I should be able to get a few more days out of each sensor. There's actually a strange sense of accomplishment when you convince the sensor it's 'new', almost like finding a five pound note or getting a free meal. Really, if I can double the life of this sensor - it's like finding £20!

So far the sensor went for an extra day, but it crashed and burned pretty much 24 hours after it was due to expire. The pump was warning me there was a 'weak signal' all day, and it finally kicked the sensor bucket at 1pm this afternoon - right before one of the meetings during which knowing my sugar levels at a needle free glance would be very handy!

I am currently trying to convince it to live again - but it's not looking good.

As for the CGM itself, there have been ups and downs, leaving me very torn about approaching decision. On one hand, I have found it to be incredibly precise at times. This morning I was 6.9 on the pump and 6.8 on the meter. After a meal, even if my blood sugar is climbing too quickly for the sensor to show the true 'value' yet, the graph screen on the pump does show that I am rising quickly, which is still informative, even if it isn't spot on.

After the sensor died this afternoon, I really did 'miss' having the graph to look at. Especially when I sat in my meeting, unsure of what my levels were and not in the right company to whip out my testing kit and bleed in front of people. Gross I know, but it's every day for a diabetic. The convenience makes for excellent peace of mind and having it there reassures me - most of the time.

The drawbacks I have found, are that when my sugars are moving rapidly, the sensor gets confused or doesn't react very quickly. For example, I got home from work yesterday and took a quick glance at the screen. Now, I know from personal experience that I drop in the afternoons, because I haven't yet perfected my basal levels. The pump was telling me I was 7.5 and dropping quickly. "OK", I thought, "I'm not far off having dinner so may as well hang on". But a couple of seconds later I reconsidered my choice and did a test, just to be sure.

I was already 3.1mmol, according to blood glucose. Now that's not good. Yes, the sensor did recognise I was falling and it did give me enough information to make the decision to test, but it was all a little late.

For me, it's really important that I know what is going on when I am going up or down too quickly. Why? When did it start? Is it a pattern? The fact that the sensor gets 'confused' is something I'm not sure that I am OK with yet. Not for £40 per week anyway.

I still have another sensor to go and on one hand I can see so many benefits. But for me as it stands, the convenience of looking at a graph and seeing a straight line, isn't quite value for money. If it could tell me more precisely when I am going up and down at speed, I could probably gain more from it.

I guess we'll have to see what the next week has in store


  1. this is really interesting to read. i would love to try a CGM (i'm still on MDI) for a day or two but like you what puts me off is the inaccuracy it can have. as you also said i like that it will show a general trend, but i don't think i'd be willing to shell out the ££ at this stage (even if by some miracle i was offered a pump!)

  2. You are spot on there. I turned it off in the end as it kept alarming all evening after a low and then the next morning told me I was 8.9 when I was actually 19.4! It was just because my sugars were going up and down so quickly, but it's still not precise enough to rely on.

    You can go for it without a pump, you just get a handset with it rather than having the information on the pump. Worth a free trial to see if it works for you. I'd like to know how you got on.....