Changes I’ve Made Since Using a Continuous Glucose Monitor


About 6 weeks ago I was given a trial of a continuous glucose monitor (CGM) and because I was aware that I would only receive 4 sensors that would last around 2 months, I planned to conduct a few experiments to get a finer understanding of diabetes. Experiments revolve around basal, bolus, exercise and takeaway food (got to have some fun, right?). I have used two sensors so far and don’t plan on using another until September when I go travelling for two weeks and then start my MA in dance and choreography. Anyway, I’ve had quite a few surprises over the past 4 weeks and feel that I have much better control now that I have seen so much data from the blood sugar graphs that were produced every 5 minutes from the Dexcom transmitter.

Changes I've Made Since Using a Continuous Glucose MonitorThe first day I wore my sensor I couldn’t believe how many times my blood sugar spiked after food. Even if it wasn’t particularly carby, it was up and down the whole day. However, with a bit of bolus manipulation and play with timing I was able to eliminate any major spikes. Most days I eat around 200 carbs, sometimes spreading them throughout the day, sometimes eating the majority of them in one go. It depends. Anyway, I found that if I took my bolus 20 minutes before eating I could get away with eating 100 carbs with no spike. Carbs could be from pasta, potato, cereal, oats, fruit etc. The only time I found this difficult is if I was eating out because I didn’t know how long food would take to be served. I figured that I could look around and see how quickly other people were being served and gauge it from there and I suppose if I were served quicker than I thought, I could save the carby part of the meal until last. Hmm, that would be testing.

Changes I've Made Since Using a Continuous Glucose MonitorBasal

My basal has almost doubled and as a result of this I haven’t woken up with a blood sugar above 7mmols in a few weeks. I have 7 different basal settings throughout the day and night. (see pic).


As a result of finding the correct basal, my bolus doses have dropped significantly. Especially in the morning because I am not chasing my blood sugar with correction doses. Also, I changed my evening insulin / carb ratio from 1/11 to 1/13. And instead of adjusting to 1/20 if exercising for an hour plus I now use 1/25 which seems to have worked so far.


Exercises is pretty much how I thought it would be because I test very regularly around my workouts anyway. However, because my basal is now at the correct rate I don’t have to increase my basal if I do morning cardio. I have to decrease it like any other time of the day. Currently reducing basal by 70% for cardio, dance, yoga, shopping, gardening and reducing by 30% for weight lifting (I have very little rest between sets) which is interesting because I also used to increase for this type of activity.

The 6 hour takeaway delay

Pizza and chips are foods I love, but rarely eat. Whenever I have eaten them in the past I would always see a spike at some point and I couldn’t quite catch when it was so I decided I would utilise the CGM to find out more.

Changes I've Made Since Using a Continuous Glucose MonitorWhen I was on holiday in Belgium I ate a large portion of fried chips in the afternoon and I saw the rise about 6 hours later whilst I was at a concert. I marked 6 hours down and decided to try again the next day by eating a very similar portion of chips, only this time I took a split bolus and released 50% of it 6 hours later. Guess what, no spike.

I tried this on another occasion with pizza which I estimated 100 carbs for and it did the trick. It seems obvious but estimating the correct amount of carbs for the pizza is paramount. I have underestimated in the past because of the reality of how many carbs there actually are in pizza (depending on the base). Don’t do this. Chances are, it’s more than you estimate anyway so be honest with your pump.

It did the trick for me but I think everyone will have a different digestion rate depending on what they have already eaten that day and how much pizza they actually eat. Bear in mind, this is really greasy, fatty pizza. Low fat pizzas digest at a normal rate. Even if I ate a full 10 inch one of 100 carbs.

Disclaimer – if I was eating oven chips of pizza that I cook at home I would not take a 6 hour split bolus because in comparison to a takeaway shop, there is nowhere near as much fat in an oven pizza like Ristorante.

Overall, I am grateful for what the CGM has taught me and I am looking forward to what my future HBA1C is after making a few of the tweaks mentioned above. If you can get your hands on 1 sensor for two weeks and are willing to put the work in and write the results down – I can assure you it will be worth it. I mean, I suppose you could conduct these experiments with a regular blood glucose meter, but it’s a little bit more painful and time consuming.

Rowena x

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