I’ve really been enjoying the posts from @Terry4 and others about how they manage such good control on a daily basis. So I thought I’d throw something out there in hopes that it’s useful to others.
Hormones and Blood Sugar
Before I got the CGM, I often felt that my blood sugar was totally random. I felt like insulin doses worked one day but not the next, and that things were very inconsistent even when I was consistent. It was very frustrating. Since getting the CGM, I’ve learned that I was actually partially right. One of the biggest things I’ve learned is how much hormonal changes impact my control as they shift throughout the month. Since getting the Dexcom six months ago, I’ve begun to respond to these shifts as quickly as I can, and I think it’s the biggest reason that my A1c has seen such improvement (from 23.5 years of being mostly above 7.0 to being 6.1 and 6.0, my lowest ever two consecutive times in a row). I’ve read that the main hormone that causes havoc throughout the month is progesterone, which is a steroid, so no wonder it has a huge impact on some women’s diabetes control!
Here is an illustration of the type of changes I need to make and the type of clues I use to help me learn when to make them. Typically, I need to increase my pump settings significantly two or three times throughout the month, and then over the course of two or three days things crash back down to where they started. But the exact dates and amounts are not always consistent, so it’s not as simple as marking dates on a calendar.
The green area on Diasend is 4.0 - 8.0 mmol/L or about 70 to 145 mg/dl. I do not eat low carb, but I do pre-bolus for meals (usually 30-45 minutes), eat moderate to low GI meals, and try to limit meals to about 30 grams of carbohydrates. I also try to pre-empt highs and lows by treating or correcting before my blood sugar crosses the alert limit and by using temporary basal rates if I think I might go high or low from exercising or stress. All days I ate the same meals and was at work (except for today, Saturday), so my schedule was identical.
Wednesday was a pretty usual day for me. The spike after breakfast was from not pre-bolusing and the evening highs were from snacking, but the rest of the day was good.
Another regular day on Thursday, except that I had a larger than usual spike after dinner that required a correction to come down into range. In hindsight, this was my first clue that my insulin sensitivity had changed, but I don’t make drastic changes after just one high, so I brushed it off at the time as a fluke.
On Friday, I rose overnight and woke up to my Dexcom alarm at 4:00 AM to take a correction bolus. Another clue that my insulin sensitivity had changed. And then I spiked after breakfast, despite adding a unit extra (trying to prevent a spike when I don’t have a lot of time to pre-bolus in the morning), and had to correct twice more during the morning to get back into range at lunch. At that point I increased all my basal rates by 0.1 u/hr. But it continued in the afternoon: spiking after lunch and needing multiple corrections to get back into range for dinner, including completely overriding my pump’s IOB tracking. At dinner I again had a big spike and had to correct multiple times. At bedtime I was still not down into range, even with a site change, so decided that it must be hormones. I increased all my basal rates by 0.1 u/hr again and also (from prior experience) adjusted my insulin to carb ratio from 1:10 to 1:8 and my insulin sensitivity factor from 2.0 mmol/L to 1.5 mmol/L. I did a final correction before bed using these new settings.
This morning I woke up to find that I’d had a great overnight period. Alwyas a good sign. Breakfast went as expected. Although the day isn’t over, I suspect the rest of the day will be as expected. But I’ll be prepared for the need to bump settings up probably twice more over the next week or two, and after that will be on the lookout for the need to quickly lower everything back down.
In all, I raised my total daily insulin dose by about 10 units over the course of one day, between the basal changes and the changes to pump settings. My total daily dose is about 40 units at its low end amd about 65 units at its high end, so it’s a change of more than 50% throughout the month. Incidentally, as I’m writing this my Dexcom is again trending upward without having eaten anything, which makes me think I may be increasing my basal rate another notch depending on how lunch and the rest of the day goes.