I now regularly use them for exercise and when I am ill and need an increased amount of insulin to keep me in range. I sometimes do this successfully and sometimes blindingly badly, but I give it a shot. But there is another time that I have found them to be particularly useful; when warding off an unwelcome overnight blood glucose level drop.
There are times when I go to bed and my continuous glucose monitor (CGM) trace shows that I am dropping, or that I have been dropping and am now teetering above 'low', but a little too close to it for comfort. At times like these in the past I would feed to raise my BGs just a little. A biscuit, a piece of toast or an apple would often suffice, but in all honesty 11pm isn't a time of night I particularly want to be snacking. That's not also considering how much weight might creep on in a year from several biscuits a week to curb a low blood sugar at night. So in recent weeks when I have seen a drop or a number I'm not too confident about leaving as it is, I've been experimenting with TBRs to restrict the amount of insulin going in, on a temporarily basis, therefore allowing my numbers to level out, or bump up just a touch.
Last night was a great example of this. At just after midnight Jamie and I crawled into bed. I'd seen a spike after my badly calculated dinner and was all too aware of the insulin I had stacked one bolus on top of another trying to get it down. Finally it was coming down, but at this time of night? C'mon!
I was 9.1mmol (164mg/do) and showing a downward arrow. Great. I don't want to eat because 9.1mmol is a little on the high side anyway and I don't particularly want to go up overnight. But I'm also fairly sure the downward trend is going to continue, with just a little insulin on board still burning a hole in my CGM picture. I could ignore, which would no doubt end in a 2am hypo, or I could eat, which I don't really want to do. So I opted for secret option C: reducing my basal rate to 0% for 1.5 hours. It seems a long time to be getting no insulin for, but something seemed instinctively right about it. That's something I believe us PWDs (people with diabetes) have a lot of, instinct.
I awoke two hours later all of a sudden. I don't know why, but after accidentally punching my husband in the back of the head after a bad dream, I figured I must have been low. I turned over, clawed around for my Dexcom receiver and with bleary eyes, squinted at the screen.
Well I'll be damned. I had nailed it, spot on. The downward trend had continued. It had continued for around two hours, having briefly danced with a 3.9 mmol around 30 minutes ago and was now heading back up, nice and safely within the very respectable 5mmol (90mg/dl) range. And back to sleep I went.
Basal rates are funny things. Something which can take days to fully adjust when you make any strategical changes can also impact your blood glucose within a matter of hours. In this case I hadn't needed to eat and was able to nod off to sleep with the use of a carefully timed basal reduction.
Game. Set. Match.